# data[].attributes.attachment_link.readable_text
Wind turbines work on a simple principle: instead of using electricity to make wind-like a fan-wind turbines use wind to make electricity. Wind turns the propeller-like blades of a turbine around a rotor, which spins a generator, which creates electricity.

Wind is a form of solar energy caused by a combination of three concurrent events:

1. The sun unevenly heating the atmosphere

2. Irregularities of the earth's surface

3. The rotation of the earth.

Wind flow patterns and speeds vary greatly across the United States and are modified by bodies of water, vegetation, and differences in terrain. Humans use this wind flow, or motion energy, for many purposes: sailing, flying a kite, and even generating electricity.

The terms "wind energy" and "wind power" both describe the process by which the wind is used to generate mechanical power or electricity. This mechanical power can be used for specific tasks (such as grinding grain or pumping water) or a generator can convert this mechanical power into electricity.

A wind turbine turns wind energy into electricity using the aerodynamic force from the rotor blades, which work like an airplane wing or helicopter rotor blade. When wind flows across the blade, the air pressure on one side of the blade decreases. The difference in air pressure across the two sides of the blade creates both lift and drag. The force of the lift is stronger than the drag and this causes the rotor to spin. The rotor connects to the generator, either directly (if it's a direct drive turbine) or through a shaft and a series of gears (a gearbox) that speed up the rotation and allow for a physically smaller generator. This translation of aerodynamic force to rotation of a generator creates electricity.

Types of Wind Turbines

The majority of wind turbines fall into two basic types:

Wind turbines can be built on land or offshore in large bodies of water like oceans and lakes. The U.S. Department of Energy is currently funding projects to facilitate offshore wind deployment in U.S. waters.

Applications of Wind Turbines

Modern wind turbines can be categorized by where they are installed and how they are connected to the grid:

Distributed Wind

When wind turbines of any size are installed on the "customer" side of the electric meter, or are installed at or near the place where the energy they produce will be used, they're called "distributed wind.

Many turbines used in distributed applications are small wind turbines. Single small wind turbines-below 100 kilowatts-are typically used for residential, agricultural, and small commercial and industrial applications.

Small turbines can be used in hybrid energy systems with other distributed energy resources, such as microgrids powered by diesel generators, batteries, and photovoltaics.

These systems are called hybrid wind systems and are typically used in remote, off-grid locations( where a connection to the utility grid is not available) and are becoming more common in grid-connected applications for resiliency.

Learn more about distributed wind from the Distributed Wind Animation or read about what the Wind Energy Technologies Office is doing to support the deployment of distributed wind systems for homes, businesses, farms, and community wind projects.

# data[].attributes.attachment_link.description
Wind turbines work on a simple principle: instead of using electricity to make wind-like a fan-wind turbines use wind to make electricity. Wind turns the propeller-like blades of a turbine around a rotor, which spins a generator, which creates electricity.

# data[].attributes.attachment_link.readable_text
Can we use sound energy to turn noise into forms of energy? Sounds crazy, but we discover different types of energy all the time - especially when it comes to renewables - and sound energy is just another kind.

Around the world, it's hard to find somewhere that noise is not part of the landscape. From the roar of traffic to the sound of musical instruments, humans make a lot of noise. There are many different types of sound ranging from the audible to the inaudible.

Sound sources may be pleasant or unpleasant to the human ear, depending on loudness, different pitches, types of sound, sound source, and sound intensity. Regardless, sound energy travels and depending on the sound source and the intensity, sound can sometimes be considered a pollutant.

So what is sound energy, exactly? Sound energy is turning sound into electricity. Though the science of turning sound energy into electricity is still emerging, it has been done. For example, microphones and speakers are examples of sound becoming electrical energy.

In fact, a group of young high-school students figured out how to produce enough electricity with sound energy to turn on a light bulb. Admittedly, that's a long way from generating enough electricity to power a home or an entire city. But it's a beginning and the science behind it is developing. Let's learn more about the intriguing world of sound, including sound energy examples.

How Do We Hear Sound Waves?

The mechanics of hearing demonstrate some of the mechanics of sound energy.

When we hear a sound, we are experiencing sound waves funneling into the ear canal and moving the eardrum, much like a drum head vibrates when struck. Different sounds make different vibrations that affect how the eardrum moves.

The vibrations travel from the eardrum via ossicles to the cochlea (a fluid-filled organ), causing surface waves that strike hair cells. Depending on the location of the hair cells in the cochlea, the brain "hears" high- or low-pitched sounds via the auditory nerve. It then translates the initial vibrations of the air molecules in the sound wave into sounds we understand.

In physics, the study of sound is known as acoustics and includes all constructs of sound.

What Is the Definition of Sound Energy?

In simple terms, sound energy comes from vibrations moving through something. Solids, liquids, and gases all transmit sound as energy waves.

Sound energy is the result when a force, either sound or pressure, makes an object or substance vibrate. That energy moves through the substance in waves. Those sound waves are called kinetic mechanical energy.

Why Are Sound Waves Called Mechanical Waves?

Sound waves are sometimes called mechanical waves because sound waves require a physical medium to propagate. Liquids, gases, or solid materials transfer the pressure variations, creating mechanical energy in waves.

Like all waves, sound waves have peaks and valleys. The peaks are called compressions, while rarefaction is the term used for the lows.

The oscillations between compression and rarefaction move through gaseous, liquid, or solid media to produce energy. The number of compression/rarefaction cycles in a given period determines the frequency of a sound wave.

Scientists measure sound energy's intensity and pressure in Pascals and decibels. Sound waves are also sometimes called pressure waves because the pressure of the sound wave moves the particles through which it passes.

How Are Sound Waves Measured?

source

Wavelength, period, amplitude, and frequency are the four primary parts of a sound wave, regardless of the wave type and the medium through which the sound travels.

Wavelength: Imagine a wave traveling along a horizontal axis; in that case, the wavelength is measured as the horizontal distance between two successive and equivalent points on the wave. Thus, in basic terms, a single wavelength is one cycle between the two equal points.

Period: A wavelength period is the time it takes a single wavelength to pass a certain point. Generally, a more extended period indicates a lower pitch.

Amplitude: We measure sound amplitude (strength or level of sound pressure) by the height of the sound wave. It's related to the relative volume of the sound. When the wave's amplitude is significant - as from a loud sound - the wave is high. The reverse is also true; softer sounds produce waves with a smaller amplitude. Lower volume equates to lower decibel (dB) levels; a decibel measures sound intensity. Zero decibels equates to the quietest sounds a human ear can hear. Decibels increase by a factor of six. A normal speaking voice is 60 dB.

Frequency: Hertz (Hz) measures a sound wave's frequency. Hertz measures a sound wave's cycles per second that pass a set point on the horizontal axis. (Remember, each process has one compression and one rarefaction.) The frequency sound waves are measured in hertz. Therefore, Hertz (Hz) indicates the number of cycles per second that pass a given location. For example, if, while speaking, your diaphragm vibrates at 900 Hz, your diaphragm generates 900 compressions (increased pressure) and 900 rarefactions (decreased pressure). Pitch is a function of how the brain interprets sound frequency. A higher pitch is the result of higher frequency; lower frequency translates as lower pitch.

Is Sound Energy Potential or Kinetic Energy?

When energy can do work but isn't actively applying force, it's called potential energy.

In physics, work is measured by the energy transferred. When something is moved over a distance by an external force, that's work.

The coiled spring of a Slinky is an example of potential energy. Until the spring is released, it's not doing work. The work occurs when the spring moves (is released), becoming kinetic energy. Kinetic energy is the energy of motion.

Sound energy can be both: either kinetic energy or potential energy.

An example might be that of a musical instrument. When the instrument is played, it generates sound waves, producing kinetic energy. But when that same musical instrument is at rest, only the potential for energy is there.

Do Sound Waves Share Characteristics and Behaviors?

In addition to a wave's primary constituents - frequency, amplitude, wavelength, and frequency - scientists categorize waves based on three distinguishing characteristics: longitudinal, transverse, and surface movement.

Using the movement of a medium's particles relative to the direction of travel is a standard method for distinguishing the kind of wave.

To understand transverse waves, we'll talk about the Slinky again. Consider a Slinky's movement as your hand alternates up and down. The energy of this "activated" Slinky moves vertically along the direction of travel, displacing the coils (which, in this case, represent wave particles) up and down.

Types of transverse waves include:

Vibrations in a guitar string

Sports fans standing up and sitting down in a synchronistic wave around a sports stadium

Electromagnetic waves, such as light and radio waves

On the other hand, longitudinal waves move the wave's energy right or left along the wave's horizontal axis. So our Slinky, when stretched out horizontally and pulsed horizontally like an accordion, will pulse horizontally along its left-right direction of travel parallel to the wave's axis.

Sound waves are longitudinal waves, as are ultrasound waves, and seismic P-waves.

The chief characteristic of a surface wave is its particles' circular motion. Only the particles on the medium's surface move circularly; the movement decreases as the particles move away from the surface.

What Are Examples of Sound Energy?
source
Sound energy occurs when an object vibrates. Noise, whether within the human range of hearing or not, is sound energy. Sonar, ultrasonic (greater than 20 kilohertz) music, speech, and environmental noise are all forms of sound energy.

Whether from an inanimate object or a sentient being, sounds come from everywhere. Some are pleasant to our hearing, some are not. Consider these sound energy examples and how they make you feel:

The high, delicate tingle or the deep, vibrant tones of a wind chime

The engine rumble, screeching tires, blaring radios, and squeaking brakes of traffic

Babies crying, babbling, screaming, and giggling

Dogs barking, growling, or howling

Telephones ringing, buzzing, or jingling

Rain patter, howling winds, and thunder

Cats purring, meowing, and scratching

Humans and animals breathing, snoring, sneezing, or wheezing

The frying, crackling, boiling, chopping, and banging of a busy kitchen

Waves crashing and withdrawing

Motors running, revving, thumping, and roaring

The soft, loud, brassy, smooth, deep, reedy, raucous, and distinct sounds of music

The low, steady white noise of air conditioning

Even when it is seemingly quiet, there is always sound.

How Does Sound Energy Produce Electricity?

Sound vibrations can become electrical energy through the principle of electromagnetic induction. Electromagnetic induction generates electrical current using a magnetic field.

When a magnetic field and a conductor, such as a wire coil, move in relationship to one another, electromagnetic induction occurs. As long as the conductor is in a closed circuit, current flows wherever the conductor crosses the lines of the magnetic force.

What Is Piezoelectricity and How Does It Relate to Sound Energy?

Piezoelectricity uses unique crystals to convert mechanical energy - in this case, sound wave energy - into electrical energy.

Under compression, the crystals act as conductors. When crystals are compressed, their structure changes and the crystal acquires a net charge. That charge can be converted to an electrical current.

Other materials, such as bone, special ceramics, and enamel, are also piezoelectric conductors. These materials have in common the ability to produce an internal electrical charge due to applied mechanical stress.

Using very-high-frequency sound waves - frequencies 100 million times higher than people can hear - piezoelectric materials become electrical signals that give off light waves in the terahertz frequency range.

Piezoelectricity unites the electrical and mechanical states of the piezoelectric material. Under compression, the material used has a current flow that changes its polarization to become an electrical charge, known as a net dipole moment.

What Is the Future of Electrical Energy Generated By Sound Energy?

As we know, sounds constantly fill our acoustic environment. Like all energy, sound energy has the potential to generate electricity. Just like the sun provides unlimited solar energy and the breeze provides wind energy, sound energy is renewable because sentient beings and insentient objects alike constantly produce sound.

While sound waves and energy production principles have long been understood, the technology to convert sound energy to electricity is in its infancy.

However, as scientists and technicians investigate and improve the technologies involved in sound-generated electricity, sound energy may produce mass electricity one day.

If that sounds like a pipe dream, remember solar and wind power were once beyond our grasp too.

Brought to you by justenergy.com

All images licensed from Adobe Stock.
Featured image:

# data[].attributes.attachment_link.title
Sound Energy: Everything You Need to Know

# data[].attributes.attachment_link.description
Learn all about the intriguing world of sound, including sound energy examples and how sound relates to the future of renewable energy

# data[].attributes.attachment_link.description
Geothermal technology extracts the heat found within the subsurface of the earth, which can be used directly for heating and cooling, or converted into electricity. However, to generate electricity, medium- or high-temperature resources are needed. These are usually located close to tectonically act…

# data[].attributes.attachment_link.title
Wind explained - U.S. Energy Information Administration (EIA)

# data[].attributes.attachment_link.description
An introduction to wind energy and how it forms, and to of the daily wind cycle.

# data[].attributes.body
Tidal energy is a form of power produced by the natural rise and fall of tides caused by the gravitational interaction between Earth, the sun, and the moon.

# data[].attributes.body
https://youtu.be/xy9nj94xvKA

# data[].attributes.attachment_link.title
How do wind turbines work? - Rebecca J. Barthelmie and Sara C. Pryor

# data[].attributes.attachment_link.readable_text
Find biodiesel fuel prices and trends.

Biodiesel is a domestically produced, renewable fuel that can be manufactured from vegetable oils, animal fats, or recycled restaurant grease for use in diesel vehicles or any equipment that operates on diesel fuel. Biodiesel's physical properties are similar to those of petroleum diesel.

Find information about biodiesel blends, production and distribution, specifications, and research and development.

Explore the benefits and considerations of using biodiesel as a vehicle fuel.

Locate biodiesel fueling stations in your area and learn about biodiesel fueling infrastructure.

Learn about vehicles that can use biodiesel and how they work, and find information about their availability, emissions, maintenance, and safety.

Find laws and incentives related to biodiesel in your area.

# data[].attributes.attachment_link.description
Find biodiesel fuel prices and trends. Biodiesel is a domestically produced, renewable fuel that can be manufactured from vegetable oils, animal fats, or recycled restaurant grease for use in diesel vehicles or any equipment that operates on diesel fuel. Biodiesel's physical properties are similar to those of petroleum diesel.

# data[].attributes.attachment_link.readable_text
Image

Photograph by Hywit Dimyadi/Shutterstock

Fossil fuels are made from decomposing plants and animals. These fuels are found in Earth's crust and contain carbon and hydrogen, which can be burned for energy. Coal, oil, and natural gas are examples of fossil fuels. Coal is a material usually found in sedimentary rock deposits where rock and dead plant and animal matter are piled up in layers. More than 50 percent of a piece of coal's weight must be from fossilized plants. Oil is originally found as a solid material between layers of sedimentary rock, like shale. This material is heated in order to produce the thick oil that can be used to make gasoline. Natural gas is usually found in pockets above oil deposits. It can also be found in sedimentary rock layers that don't contain oil. Natural gas is primarily made up of methane.

According to the U.S. National Academies of Sciences, 81 percent of the total energy used in the United States comes from coal, oil, and natural gas. This is the energy that is used to heat and provide electricity to homes and businesses and to run cars and factories. Unfortunately, fossil fuels are a nonrenewable resource and waiting millions of years for new coal, oil, and natural gas deposits to form is not a realistic solution. Fossil fuels are also responsible for almost three-fourths of the emissions from human activities in the last 20 years. Now, scientists and engineers have been looking for ways to reduce our dependence on fossil fuels and to make burning these fuels cleaner and healthier for the environment.

Scientists across the country and around the world are trying to find solutions to fossil fuel problems so that there is enough fuel and a healthy environment to sustain human life and activities in the future. The United States Department of Energy is working on technologies to make commercially available natural-gas-powered vehicles. They are also trying to make coal burning and oil drilling cleaner. Researchers at Stanford University in California have been using greener technologies to figure out a way to burn fossil fuels while lessening their impact on the environment. One solution is to use more natural gas, which emits 50 percent less carbon dioxide into the atmosphere than coal does. The Stanford team is also trying to remove carbon dioxide from the atmosphere and store it underground-a process called carbon capture and sequestration. Scientists at both Stanford and the University of Bath in the United Kingdom are trying something completely new by using carbon dioxide and sugar to make renewable plastic.

Director

Tyson Brown, National Geographic Society

Author

National Geographic Society

Production Managers

Gina Borgia, National Geographic Society

Jeanna Sullivan, National Geographic Society

Program Specialists

Sarah Appleton, National Geographic Society, National Geographic Society

Margot Willis, National Geographic Society

Last Updated

October 19, 2023

For information on user permissions, please read our Terms of Service. If you have questions about how to cite anything on our website in your project or classroom presentation, please contact your teacher. They will best know the preferred format. When you reach out to them, you will need the page title, URL, and the date you accessed the resource.

Media

If a media asset is downloadable, a download button appears in the corner of the media viewer. If no button appears, you cannot download or save the media.

Text

Text on this page is printable and can be used according to our Terms of Service.

Interactives

Any interactives on this page can only be played while you are visiting our website. You cannot download interactives.

# data[].attributes.attachment_link.description
What is a fossil fuel and what is being done to make fossil fuels more environmentally friendly?

# data[].attributes.attachment_link.readable_text
It's no secret that solar energy is good for the environment. Reducing reliance on harmful fossil fuels alleviates strain on limited resources and ensures the planet will remain a healthy habitat. But when bringing solar into your own domain, there is much to be considered. Take time to get acquainted with the benefits, and natural drawbacks it can present to both business and homeowners. If you are interested in making the switch to solar energy, it is important for you to know the full scope of your investment, so we've tackled the top advantages and disadvantages of making the change.

Advantages of Solar Energy

Disadvantages of Solar Energy

Reduces Electricity Bills

High Initial Costs

Provides Tax Incentives

Time Consuming

Pairs with Solar Battery Storage

Weather Dependent

Environmentally Friendly

Stringent Criteria

The Advantages of Solar Energy

#1. Solar energy reduces your monthly power bill

One of the most significant benefits that solar energy will present to you right away is a lower utility bill. Because your energy needs are being met by your new solar system, your energy bills will drop significantly. In fact, you may even receive credits for the surplus energy that your system produces, which will offset your bill even more.

#2. Solar energy provides lucrative tax incentives

The most talked-about benefits of solar energy are the tax incentives associated with it. Right now, qualifying homeowners who opt to get solar panels can get 26% of their total initial costs back in a federal tax credit. New York State also has a $5,000 tax credit. These incentives have not only given homeowners a faster return on investment for their solar power expenditure, but have also created jobs and caused the solar energy industry to dramatically expand in a relatively short amount of time. The catch is that the incentive programs do have expiration dates, so waiting to install in the future could mean missing out on incentives and major reimbursements.

#3. Solar energy can be paired with solar battery storage

Solar panels and battery storage are an ideal combination when paired together. Battery storage allows you to store electricity and discharge it for later use, which is perfect for people who want to self-produce all of their own power and don't want to be reliant on the power grid or use fossil fuel generators. Home battery backup systems are designed to charge during the day and homeowners can either use that power at night, or save it up to power the house when the grid is down. We recommend having more than one battery installed to be sure that you have enough energy to power your home whenever you need it. Our standard package is two Tesla Powerwall units.

#4. Solar energy is environmentally-friendly

Solar energy is a clean, renewable resource. Many Americans are looking for ways they can be more environmentally-friendly, and solar power checks a lot of boxes. Solar panels are, of course, powered by the sunlight, so as you're powering your home, you greatly reduce the emissions you put out into the environment. Additionally, solar energy is not generally associated with pollution, so you will lessen your carbon footprint.

The Disadvantages of Solar Energy

With all the benefits that solar energy provides, there are some drawbacks that need to be discussed.

#5. Initial costs can be high

Even though renewable energy sources have greatly reduced in cost over the last decade, buying a solar system isn't cheap on day one. In fact, the initial cost of purchasing a solar panel system can be fairly high because you are essentially pre-paying your next 40 years of electricity. While the savings is enormous, not everyone can purchase a system outright, so financing packages are available to allow homeowners to pay-as-you-go and start saving from month one.

A solar system includes solar panels, inverters, wiring, and installation, all of which need to be paid for upfront. That being said, installing solar avoids utility electric bills, so it more than pays for itself over time. Switching to solar with a high quality company maximizes your investment and helps you make the best financial decision you can when it comes to solar. Many banks now offer great financing options and offer free online quotes so you can have all the information you need to move forward.

#6. The permitting process can be time consuming

Many people don't know this, but before installation can occur, you need to have an approved permit from your local government office. Going solar is unlike getting a new roof or replacing your home's windows. Government restrictions can add weeks to months to a project installation. Depending on how strict your local government is and how quickly permits are approved, the process can be drawn out. Because this can be a time-consuming and burdensome procedure, we take on that responsibility by managing the entire permitting process with your local government. Going into your solar project, keep in mind, that this step can add time to a project. It's important to have a clear understanding of the timeline provided by your installer and to stay in close communication with your project manager to make sure this process go as smoothly as possible.

#7. Weather Dependence

Because solar panels rely on the sun to produce energy, you may produce less electricity on cloudy or rainy days. Luckily, however, solar panels don't need 100% sunlight to work and, depending on the cloud density, your solar panels will still be able to pick up some of the sun's energy to give you ample amounts of power your home can bank. Additionally, many users generate excess energy credits in the summer months that can be used during periods of less sunlight like evening and winter time. So if the sun isn't shining, your credit bank is working for you!

#8. Not every roof will meet the criteria for solar

Individual energy needs, available roof space, roof orientation, roof material, shading, and orientation all factor in to determining if your home is suitable for solar. For example, a large, south-facing roof without roof obstructions (like vent pipes and skylights) would be ideal for solar, whereas a system on a small, west-facing roof surrounded by tall trees may not be able to produce the same amount of energy.

We'd love to power the whole world with the sun, but we'll be honest if your home isn't ideal for solar panels. Luckily, community solar is available in our region. You can subscribe to a local project to virtually offset your bill with renewable energy and save an average of 10% monthly.

Get a Free Solar Estimate Today!

There's a reason solar energy systems are becoming more and more popular. Their environmental and financial benefits prove to be worthwhile. Curious if your home or business would be a good candidate for a solar power system? Contact us to start the conversation!

# data[].attributes.attachment_link.title
The Advantages & Disadvantages of Solar Energy - 7 Pros and Cons

# data[].attributes.attachment_link.description
It's no secret that solar energy is good for the environment. Reducing reliance on harmful fossil fuels alleviates strain on limited resources and ensures the planet will remain a healthy habitat. But when bringing solar into your own domain, there is much to be considered.

# data[].attributes.attachment_link.readable_text
What is Hydropower?

Hydropower, or hydroelectric power, is one of the oldest and largest sources of renewable energy, which uses the natural flow of moving water to generate electricity. Hydropower currently accounts for 28.7% of total U.S. renewable electricity generation and about 6.2% of total U.S. electricity generation.

While most people might associate the energy source with the Hoover Dam-a huge facility harnessing the power of an entire river behind its wall- hydropower facilities come in all sizes. Some may be very large, but they can be tiny, too, taking advantage of water flows in municipal water facilities or irrigation ditches. They can even be "damless," with diversions or run-of-river facilities that channel part of a stream through a powerhouse before the water rejoins the main river. Whatever the method, hydropower is much easier to obtain and more widely used than most people realize. In fact, all but two states (Delaware and Mississippi) use hydropower for electricity, some more than others. For example, in 2020 about 66% of the state of Washington's electricity came from hydropower.

In a study led by the National Renewable Energy Laboratory on hydropower flexibility, preliminary analysis found that the firm capacity associated with U.S. hydropower's flexibility is estimated to be over 24 GW. To replace this capability with storage would require the buildout of 24 GW of 10-hour storage-more than all the existing storage in the United States today. Additionally, in terms of integrating wind and solar, the flexibility presented in existing U.S. hydropower facilities could help bring up to 137 gigawatts of new wind and solar online by 2035.

How Does Hydropower Work?

Hydropower technologies generate power by using the elevation difference, created by a dam or diversion structure, of water flowing in on one side and out, far below, on the other. The Department of Energy's "Hydropower 101" video explains how hydropower works and highlights some of the research and development efforts of the Water Power Technologies Office (WPTO) in this area.

What is the cost of Hydropower?

Hydropower is an affordable source of electricity that costs less than most. Since hydropower relies only on the energy from moving water, states that get the majority of their electricity from hydropower, like Idaho, Washington, and Oregon, have lower energy bills than the rest of the country.

Compared to other electricity sources, hydropower also has relatively low costs throughout the duration of a full project lifetime in terms of maintenance, operations, and fuel. Like any major energy source, significant upfront costs are unavoidable, but hydropower's longer lifespan spreads these costs out over time. Additionally, the equipment used at hydropower facilities often operates for longer periods of time without needing replacements or repairs, saving money in the long term.

The installation costs for large hydropower facilities consist mostly of civil construction works (such as the building of the dams, tunnels, and other necessary infrastructure) and electromechanical equipment costs (electricity-generating machinery). Since hydropower is a site-specific technology, these costs can be minimized at the planning stage through proper selection of location and design.

WHAT ARE THE BENEFITS OF HYDROPOWER?

The benefits of hydropower have been recognized and harnessed for thousands of years. In addition to being a clean and cost-effective form of energy, hydropower plants can provide power to the grid immediately, serving as a flexible and reliable form of backup power during major electricity outages or disruptions. Hydropower also produces a number of benefits outside of electricity generation, such as flood control, irrigation support, and water supply.

WHAT IS THE HISTORY OF HYDROPOWER?

The history of hydropower dates back thousands of years. For example, the Greeks used water wheels to grind wheat into flour more than 2,000 years ago. The evolution of the modern hydropower turbine began in the mid-1700s when a French hydraulic and military engineer, Bernard Forest de Bélidor, wrote Architecture Hydraulique. Many key developments in hydropower technology occurred during the first half of the 19th century, and more recently, the past century has seen a number of hydroelectric advancements that have helped hydropower become an integral part of the renewable energy mix in the United States.

To learn how to join the hydropower industry and more about science, technology, engineering, and mathematics (STEM) workforce development opportunities, visit the Hydropower STEM Portal.

# data[].attributes.attachment_link.description
Hydropower, or hydroelectric power, is one of the oldest and largest sources of renewable energy, which uses the natural flow of moving water to generate electricity.

# data[].attributes.attachment_link.description
On these pages you’ll find helpful publications, software, and websites for the geothermal community and stakeholders.

# data[].attributes.attachment_link.readable_text
Hydropower-energy created from fresh, moving water-is the world's oldest form of renewable energy.

Over 2,000 years ago, the ancient Greeks used the power in rivers and streams to rotate wooden wheels and crush grain to make bread. Today, we still use this water power to generate clean, affordable electricity for everything from factories (that grind far more grain than the Greeks did) to our ovens that let us bake our bread at home.

What Is Hydropower?

Humans have used water power for centuries. But we didn't start making hydropower-electricity from our rivers, streams, and lakes-until just over 100 years ago, not too long after Thomas Edison invented electric power. Today, instead of using large, wooden wheels, we use propeller-like devices called turbines, which spin as water rushes through them, generating electricity. But hydropower has a secret power: It can also store huge amounts of renewable energy to use when other sources dry up.

Right now, hydropower provides about 7% of the United States' electricity and about 40% of our renewable energy. And almost every state uses it. The oldest form of renewable energy, it's also one of the most affordable and can provide a clean, sustainable, and reliable way to power our lives for centuries to come.

In the past, we often created hydropower with large dams, but today's structures are typically far smaller, which means they can better protect fish and other critical wildlife and plants that depend on these waters to survive. Photo from Mark König, Unsplash

How Does Hydropower Work?

Most of the country's hydropower facilities were built in lakes, streams, and rivers decades ago. They often used large dams that block the water's flow, creating a pool of water above the structure. One or more pipes give that pooled water a path to surge downhill. And as the water rushes through those pipes, it spins a turbine, which runs a generator that sends clean electricity to your home.

Today, most newly constructed hydropower facilities are far smaller and use new techniques to better protect the wildlife and plants that rely on naturally flowing waterways. Fish, for example, must migrate upstream to feed and mate. To help them navigate around our dams, we build fish ladders, so they can climb over the top and swim on. Or we don't block their path at all; some new hydropower facilities divert part of a river or stream into a separate channel. That way, the river and its ecosystem can race on, undisturbed, while we generate power off to the side.

Some hydropower facilities don't just generate power; they store it in the largest "batteries" on Earth. So-called pumped storage hydropower-also known as water batteries-can hold huge amounts of renewable energy for months at a time. This storage is very important. Solar energy and wind power only create electricity when the sun shines and winds blow, but water batteries can store excess energy that can be used at night or during gentle breezes. In the United States, they can store up to 553 gigawatt-hours of energy. That could power the entire country's video gaming for about a week.

Pumped storage hydropower can be either open (left) or closed loop (right). Because closed-loop pumped storage hydropower does not connect to natural waterways, this newer technology can help protect local water quality and ecosystems. Illustration by NREL

What Makes Hydropower So Great?

Hydropower costs less than most other energy sources, making it an affordable source of renewable energy. Except during periods of extreme drought, we can count on water to flow day and night and all year round. And this consistency is critical if we want to rely purely on clean energy sources, such as solar energy and wind power, which can come and go.

New hydropower technologies keep getting better, too. They make it easier to build new facilities without too much disruption to the local environment. And they help cut construction costs, which could make hydropower even more affordable, potentially reducing energy bills across the country.

Hydropower facilities can also control how much water flows through their turbines and, therefore, how much energy they produce and when. That way, hydropower can fill energy gaps to ensure communities always get the power they need-or restore it. When ice storms, wildfires, or even hackers stop the electric grid from lighting up our lives, hydropower can help. In almost half of all blackouts, it's water that turns the lights back on. Losing power during a heat wave or at a hospital is not just inconvenient; it can be dangerous. Hydropower can save lives.

What Else Can Hydropower Do?

Water housed in hydropower facilities can be used to water crops, put out wildfires, or provide clean drinking water to local communities.

In some areas, such as the drier Western states, the warming climate is likely to cause more droughts, which could threaten water supplies. Because hydropower facilities can absorb and store extra water, they can help communities manage their supplies. In the Northeast, on the other hand, climate change is likely to cause more flooding. Hydropower can help with that, too. Its reservoirs can capture dangerous run-off, preventing those waters from surging into towns and cities where it can threaten properties and lives.

Additional Resources

For more information about hydropower, browse the following resources.

NREL's Hydropower Research - news and updates about NREL's hydropower studies and innovations

An Examination of the Hydropower Licensing and Federal Authorization Process, NREL Technical Report (2021)

Hydropower Fact Sheet, U.S. Department of Energy's Water Power Technologies Office (2021)

Hydropower Basics
U.S. Department of Energy's Office of Energy Efficiency and Renewable Energy

How Hydropower Works
U.S. Department of Energy's Office of Energy Efficiency and Renewable Energy

Hydropower Stories
In the 1970s, Hydropower Was Gold. What Happened? Hydropower Means Flexible Power for Our Clean Energy Future FLASH: Meet the New Superhero of Hydropower RAPID Changes Are Coming for Hydropower NREL Announces Winners of the Groundbreaking Hydro Prize
Read more stories about how hydropower could help communities take charge of their energy production, save money, and support a healthy planet.

# data[].attributes.attachment_link.description
Hydropower-energy created from fresh, moving water-is the world's oldest form of renewable energy. Over 2,000 years ago, the ancient Greeks used the power in rivers and streams to rotate wooden wheels and crush grain to make bread.

# data[].attributes.attachment_link.readable_text
Biomass-renewable energy from plants and animals

Biomass is renewable organic material that comes from plants and animals. Biomass contains stored chemical energy from the sun that is produced by plants through photosynthesis. Biomass can be burned directly for heat or converted to liquid and gaseous fuels through various processes

Biomass was the largest source of total annual U.S. energy consumption until the mid-1800s. In 2022, biomass accounted for nearly 5% of U.S. total primary energy consumption. Biomass is used for heating and electricity generation and as a transportation fuel. Biomass is an important fuel in many countries, especially for cooking and heating in developing countries.

Wood and wood processing waste-firewood, wood pellets, and wood chips, lumber and furniture mill sawdust and waste, and black liquor from pulp and paper mills

Agricultural crops and waste materials-corn, soybeans, sugar cane, switchgrass, woody plants, algae, and crop and food processing residues, mostly to produce biofuels

Biogenic materials in municipal solid waste-paper products; cotton and wool products; and food, yard, and wood wastes

Animal manure and human sewage for producing biogas (renewable natural gas)

Biomass can be converted to energy in different ways

Biomass is converted to energy through various processes, including:

Direct combustion (burning) to produce heat

Thermochemical conversion to produce solid, gaseous, and liquid fuels

Chemical conversion to produce liquid fuels

Biological conversion to produce liquid and gaseous fuels

Direct combustion is the most common method for converting biomass to useful energy. All biomass can be burned directly for heating buildings and water, for providing industrial process heat, and for generating electricity in steam turbines.

Thermochemical conversion of biomass includes pyrolysis and gasification. Both processes are thermal decomposition processes wherein biomass feedstock materials are heated in closed, pressurized vessels called gassifiers at high temperatures. The processes mainly differ in the temperatures and in the amount of oxygen present during conversion.

Pyrolysis entails heating organic materials to between 800&deg F and 900&deg F (400&deg C and 500&deg C) in the nearly complete absence of free oxygen. Biomass pyrolysis produces fuels such as charcoal, bio-oil, renewable diesel, methane, and hydrogen.

Hydrotreating is used to process bio-oil (produced by fast pyrolysis) with hydrogen under elevated temperatures and pressures in the presence of a catalyst to produce renewable diesel, renewable gasoline, and renewable jet fuel.

Gasification entails heating organic materials to between 1,400&deg F and 1,700 F (800&deg C and 900&deg C) with injections of controlled amounts of free oxygen or steam into the vessel to produce a carbon monoxide- and hydrogen-rich gas called synthesis gas or syngas. Syngas can be used as a fuel for diesel engines, for heating, and for generating electricity in gas turbines. It can also be treated to separate the hydrogen from the gas, and the hydrogen can be burned or used in fuel cells. The syngas can be further processed to produce liquid fuels using the Fischer-Tropsch process.

A chemical conversion process known as transesterification is used for converting vegetable oils, animal fats, and greases into fatty acid methyl esters (FAME) to produce biodiesel.

Biological conversion of biomass includes fermentation to make ethanol and anaerobic digestion to produce biogas. Ethanol is used as a vehicle fuel. Biogas, also called biomethane or renewable natural gas, is produced in anaerobic digesters at sewage treatment plants and at dairy and livestock operations. It also forms in and may be captured from solid waste landfills. Properly treated renewable natural gas has the same uses as fossil fuel natural gas.

Researchers are working on ways to improve these methods and to develop other ways to convert and use more biomass for energy.

Biomass provided about 5% of U.S. energy in 2022

In 2022, biomass accounted for 5% of U.S. energy consumption, or about 4,930 trillion British thermal units (TBtu). The types, amounts, and the percentage shares of total biomass energy consumption in 2022 were:

Biofuels-2,419 TBtu-49%

Wood and wood waste-1,984 TBtu-43%

Municipal solid waste, animal manure, and sewage-411 TBtu-8%

The industrial sector is the largest consumer of biomass for energy in the United States

The amounts-in TBtu-and percentage shares of total U.S. biomass energy use by consuming sector in 2022 were:

The industrial sector accounted for the most, in terms of energy content and percentage share, of total annual U.S. biomass consumption in 2022. The wood products and paper industries use biomass in combined heat and power plants for process heat and to generate electricity for their own use.

The transportation sector accounted for the second-highest amount and percentage share of biomass (as biofuels) consumption in 2022.

The residential and commercial sectors use firewood and wood pellets for heating. The commercial sector also consumes, and in some cases, sells renewable natural gas produced at municipal sewage treatment facilities and at waste landfills.

The electric power sector uses wood and biomass-derived wastes to generate electricity for sale to the other sectors.

The United States is a net exporter of biomass energy

On an energy content basis, U.S. total biomass energy exports exceeded total biomass energy imports in 2022.

Densified biomass fuels (wood pellets and other densified biomass fuels) have become a U.S. export commodity in recent years. In 2022, the United States exported about 8.8 million tons of wood fuel pellets ( Table 8).
Last updated: June 30, 2023, with data from the Monthly Energy Review, April 2023; data for 2022 are preliminary.

# data[].attributes.attachment_link.description
How is biomass, such as plants, wood, paper and lumber mills waste, and municipal garbage converted into heat, into biogas, or into liquid biofuels.

# data[].attributes.body
https://www.ducksters.com/science/environment/biomass_energy.php

# data[].attributes.attachment_link.description
Kids learn about biomass energy and how this renewable power can help the environment. Teach students about biodiesel, ethanol, and methane gas.

# data[].attributes.attachment_link.readable_text
How wind turbines work

Wind turbines use blades to collect the wind's kinetic energy. Wind flows over the blades creating lift (similar to the effect on airplane wings), which causes the blades to turn. The blades are connected to a drive shaft that turns an electric generator, which produces (generates) electricity.

Diagram of wind turbine components

Electricity generation with wind

The amount of wind electricity generation has grown significantly in the past 30 years. Advances in wind energy technology have decreased the cost of producing electricity from wind, and government and other incentives in the United States and in other countries have encouraged growth in wind power.

Total annual U.S. electricity generation from wind energy increased from about 6 billion kilowatthours (kWh) in 2000 to about 338 billion kWh in 2020. In 2020, wind turbines were the source of about 8.4% of total U.S. utility-scale electricity generation. Utility scale includes facilities with at least one megawatt (1,000 kilowatts) of electricity generation capacity.
Last updated: March 17, 2021

# data[].attributes.attachment_link.title
Electricity generation from wind - U.S. Energy Information Administration (EIA)

# data[].attributes.attachment_link.description
Wind turbines use blades to collect the wind's kinetic energy. Wind flows over the blades creating lift (similar to the effect on airplane wings), which causes the blades to turn. The blades are connected to a drive shaft that turns an electric generator, which produces (generates) electricity.

# data[].attributes.body
https://www.eia.gov/energyexplained/use-of-energy/homes.php

# data[].attributes.attachment_link.readable_text
More than half of energy use in homes is for heating and air conditioning

U.S. households need energy to power numerous home devices and equipment, but on average, more than half (51% in 2015) of a household's annual energy consumption is for just two energy end uses: space heating and air conditioning. These mostly seasonal and energy-intensive uses vary significantly by geographic location, home size and structure, and equipment and fuels used.

Water heating, lighting, and refrigeration are near-universal and year-round home energy uses. In 2015, these three end uses combined accounted for 27% of total annual home energy use. The remaining share-21%-of home energy use was for devices such as televisions, cooking appliances, clothes washers, and clothes dryers, as well as a growing list of consumer electronics including computers, tablets, smartphones, video game consoles, and internet streaming devices.

Many factors affect the amount of energy a household uses

Geographic location and climate

Type of home and its physical characteristics

Number, type, and efficiency of energy-consuming devices in the home and the amount of time they are used

Number of household members

Because of higher space-heating demand, households in the Northeast and Midwest regions of the United States consume more energy on average than households in the South and West regions. Larger homes and larger households tend to use more energy overall than smaller homes and smaller households.

Space heating and air conditioning account for a much smaller share of household energy use in apartments than in detached single-family homes. Apartments are generally smaller than single-family homes, and they are often partially insulated from weather by adjacent apartments. In 2015, the average household living in a single-family detached home consumed nearly three times more energy than a household living in an apartment building that has five or more apartments.

Electricity and natural gas are the most-used energy sources in homes

Electricity is used in almost all homes, and electricity accounted for 41% of household end-use energy consumption in 2019. Natural gas, which was used in 58% of homes in 2015, accounted for 44% of residential sector end-use energy consumption in 2019. Petroleum was the next most-consumed energy source in the residential sector in 2019. Petroleum includes fuel oil, kerosene, and liquefied petroleum gas (LPG), which is mostly propane. Natural gas, fuel oil, and LPG are all primarily used for space heating and water heating, but electricity powers heating devices and many more end uses.

Overall, three-quarters of U.S. homes use two or more energy sources, but mobile homes and homes in the South are most likely to only use electricity to meet all of their household energy needs. Fuel oil use for heating is more common in the Northeast. LPG use for grilling food outdoors is common throughout the country, while many homes in rural areas use LPG to meet the majority of heating and cooking needs.

Energy use per household has declined

Improvements in building insulation and materials

Improved efficiencies of heating and cooling equipment, water heaters, refrigerators, lighting, and appliances

Population migration to regions with lower heating-and thus lower total energy-demand

The decline in average household site energy consumption has offset the increase in the number of homes overall, resulting in relatively flat residential sector energy consumption since the mid-1990s.
Last updated: August 4, 2020

# data[].attributes.attachment_link.title
Use of energy in homes - U.S. Energy Information Administration (EIA)

# data[].attributes.attachment_link.description
U.S. households need energy to power numerous home devices and equipment, but on average, more than half (51% in 2015) of a household's annual energy consumption is for just two energy end uses: space heating and air conditioning. These mostly seasonal and energy-intensive uses vary significantly by geographic location, home size and structure, and equipment and fuels used.

# data[].attributes.attachment_link.readable_text
The potential issues surrounding the use of fossil fuels, particularly in terms of climate change, were considered earlier than you may think. It was a Swedish scientist named Svante Arrhenius who was the first to state that the use of fossil fuel could contribute to global warming, way back in 1896.

The issue has become a hot-button topic over the course of the last few decades. Today, there is a general shift towards environmental awareness and the sources of our energy are coming under closer scrutiny.

This has led to the rise of a number of alternative energy sources. While the viability of each can be argued, they all contribute something positive when compared to fossil fuels.

Lower emissions, lower fuel prices and the reduction of pollution are all advantages that the use of alternative fuels can often provide.

Here we examine eleven of the most prominent alternative fuel sources and look at the benefits they offer and potential for increased uptake in the coming years.

Here are some examples of Alternative Energy Sources and Their Importance

1. Hydrogen Gas

Unlike other forms of natural gas, hydrogen is a completely clean burning fuel. Once produced, hydrogen gas cells emit only water vapor and warm air when in use.

The major issue with this form of alternative energy is that it is mostly derived from the use of natural gas and fossil fuels. As such, it could be argued that the emissions created to extract it counteract the benefits of its use.

The process of electrolysis, which is essential for the splitting of water into hydrogen and oxygen, makes this less of an issue. However, electrolysis still ranks below the previously mentioned methods for obtaining hydrogen, though research continues to make it more efficient and cost-effective.

2. Tidal Energy

While tidal energy uses the power of water to generate energy, much like with hydroelectric methods, its application actually has more in common with wind turbines in many cases.

Though it is a fairly new technology, its potential is enormous. A report produced in the United Kingdom estimated that tidal energy could meet as much as 20% of the UK's current electricity demands.

The most common form of tidal energy generation is the use of Tidal Stream Generators. These use the kinetic energy of the ocean to power turbines, without producing the waste of fossil fuels or being as susceptible to the elements as other forms of alternative energy.

3. Biomass Energy

Biomass energy comes in a number of forms. Burning wood has been used for thousands of years to create heat, but more recent advancements have also seen waste, such as that in landfills, and alcohol products used for similar purposes.

Focusing on burning wood, the heat generated can be equivalent to that of a central heating system. Furthermore, the costs involved tend to be lower and the amount of carbon released by this kind of fuel falls below the amount released by fossil fuels.

However, there are a number of issues that you need to consider with these systems, especially if installed in the home. Maintenance can be a factor, plus you may need to acquire permission from a local authority to install one.

4. Wind Energy

This form of energy generation has become increasingly popular in recent years. It offers much the same benefits that many other alternative fuel sources do in that it makes use of a renewable source and generates no waste.

Current wind energy installations power roughly twenty million homes in the United States per year and that number is growing. Most states in the nation now have some form of wind energy set-up and investment into the technology continues to grow.

Unfortunately, this form of energy generation also presents challenges. Wind turbines restrict views and may be dangerous to some forms of wildlife.

5. Geothermal Power

At its most basic, geothermal power is about extracting energy from the ground around us. It is growing increasingly popular, with the sector as a whole experiencing five percent growth in 2015.

The World Bank currently estimates that around forty countries could meet most of their power demands using geothermal power.

This power source has massive potential while doing little to disrupt the land. However, the heavy upfront costs of creating geothermal power plants has led to slower adoption than may have been expected for a fuel source with so much promise.

6. Natural Gas

Natural gas sources have been in use for a number of decades, but it is through the progression of compression techniques that it is becoming a more viable alternative energy source. In particular, it is being used in cars to reduce carbon emissions.

Demand for this energy source has been increasing. In 2016, the lower 48 states of the United States reached record levels of demand and consumption.

Despite this, natural gas does come with some issues. The potential for contamination is larger than with other alternative fuel sources and natural gas still emits greenhouse gases, even if the amount is lower than with fossil fuels.

7. Biofuels

In contrast to biomass energy sources, biofuels make use of animal and plant life to create energy. In essence they are fuels that can be obtained from some form of organic matter.

They are renewable in cases where plants are used, as these can be regrown on a yearly basis. However, they do require dedicated machinery for extraction, which can contribute to increased emissions even if biofuels themselves don't.

Biofuels are increasingly being adopted, particularly in the United States. They accounted for approximately seven percent of transport fuel consumption as of 2012.

8. Wave Energy

Water again proves itself to be a valuable contributor to alternative energy fuel sources with wave energy converters. These hold an advantage over tidal energy sources because they can be placed in the ocean in various situations and locations.

Much like with tidal energy, the benefits come in the lack of waste produced. It is also more reliable than many other forms of alternative energy and has enormous potential when used properly.

Again, the cost of such systems is a major contributing factor to slow uptake. We also don't yet have enough data to find out how wave energy converters affect natural ecosystems.

9. Hydroelectric Energy

Hydroelectric methods actually are some of the earliest means of creating energy, though their use began to decline with the rise of fossil fuels. Despite this, they still account for approximately seven percent of the energy produced in the United States.

Hydroelectric energy carries with it a number of benefits. Not only is it a clean source of energy, which means it doesn't create pollution and the myriad issues that arise from it, but it is also a renewable energy source.

Better yet, it also offers a number of secondary benefits that are not immediately apparent. The dams used in generating hydroelectric power also contribute to flood control and irrigation techniques.

10. Nuclear Power

Nuclear power is amongst the most abundant forms of alternative energy. It creates a number of direct benefits in terms of emissions and efficiency, while also boosting the economy by creating jobs in plant creation and operation.

Thirteen countries relied on nuclear power to produce at least a quarter of their electricity as of 2015 and there are currently 450 plants in operation throughout the world.

The drawback is that when something goes wrong with a nuclear power plant the potential for catastrophe exists. The situations in Chernobyl and Fukushima are examples of this.

11. Solar Power

When most people think of alternative energy sources they tend to use solar power as an example. The technology has evolved massively over the years and is now used for large-scale energy production and power generation for single homes.

A number of countries have introduced initiatives to promote the growth of solar power. The United Kingdom's 'Feed-in Tariff' is one example, as is the United States' ' Solar Investment Tax Credit'.

This energy source is completely renewable and the costs of installation are outweighed by the money saved in energy bills from traditional suppliers. Nevertheless, solar cells are prone to deterioration over large periods of time and are not as effective in unideal weather conditions.

In Conclusion

As the issues that result from the use of traditional fossil fuels become more prominent, alternative fuel sources like the ones mentioned here are likely to gain further importance.

Their benefits alleviate many of the problems caused by fossil fuel use, particularly when it comes to emissions. However, the advancement of some of these technologies has been slowed down due to the amount of investment needed to make them viable.

Through combining them all we may be able to positively affect issues like climate change, pollution and many others.

Please do contribute to the discussion below and let us know your thoughts on alternative energy sources in the comments section or by sharing this article on social media.

Resources

# data[].attributes.attachment_link.title
11 Alternative Energy Sources (With Examples)

# data[].attributes.attachment_link.description
The potential issues surrounding the use of fossil fuels, particularly in terms of climate change, were considered earlier than you may think. It was a Swedish scientist named Svante Arrhenius who was the first to state that the use of fossil fuel could contribute to global warming, way back in 1896.

# data[].attributes.attachment_link.readable_text
Wind turbines work on a simple principle: instead of using electricity to make wind-like a fan-wind turbines use wind to make electricity. Wind turns the propeller-like blades of a turbine around a rotor, which spins a generator, which creates electricity.

Wind is a form of solar energy caused by a combination of three concurrent events:

1. The sun unevenly heating the atmosphere

2. Irregularities of the earth's surface

3. The rotation of the earth.

Wind flow patterns and speeds vary greatly across the United States and are modified by bodies of water, vegetation, and differences in terrain. Humans use this wind flow, or motion energy, for many purposes: sailing, flying a kite, and even generating electricity.

The terms "wind energy" and "wind power" both describe the process by which the wind is used to generate mechanical power or electricity. This mechanical power can be used for specific tasks (such as grinding grain or pumping water) or a generator can convert this mechanical power into electricity.

A wind turbine turns wind energy into electricity using the aerodynamic force from the rotor blades, which work like an airplane wing or helicopter rotor blade. When wind flows across the blade, the air pressure on one side of the blade decreases. The difference in air pressure across the two sides of the blade creates both lift and drag. The force of the lift is stronger than the drag and this causes the rotor to spin. The rotor connects to the generator, either directly (if it's a direct drive turbine) or through a shaft and a series of gears (a gearbox) that speed up the rotation and allow for a physically smaller generator. This translation of aerodynamic force to rotation of a generator creates electricity.

Types of Wind Turbines

The majority of wind turbines fall into two basic types:

Wind turbines can be built on land or offshore in large bodies of water like oceans and lakes. The U.S. Department of Energy is currently funding projects to facilitate offshore wind deployment in U.S. waters.

Applications of Wind Turbines

Modern wind turbines can be categorized by where they are installed and how they are connected to the grid:

Distributed Wind

When wind turbines of any size are installed on the "customer" side of the electric meter, or are installed at or near the place where the energy they produce will be used, they're called "distributed wind.

Many turbines used in distributed applications are small wind turbines. Single small wind turbines-below 100 kilowatts-are typically used for residential, agricultural, and small commercial and industrial applications.

Small turbines can be used in hybrid energy systems with other distributed energy resources, such as microgrids powered by diesel generators, batteries, and photovoltaics.

These systems are called hybrid wind systems and are typically used in remote, off-grid locations( where a connection to the utility grid is not available) and are becoming more common in grid-connected applications for resiliency.

Learn more about distributed wind from the Distributed Wind Animation or read about what the Wind Energy Technologies Office is doing to support the deployment of distributed wind systems for homes, businesses, farms, and community wind projects.

# data[].attributes.attachment_link.description
Wind turbines work on a simple principle: instead of using electricity to make wind-like a fan-wind turbines use wind to make electricity. Wind turns the propeller-like blades of a turbine around a rotor, which spins a generator, which creates electricity.

# data[].attributes.body
https://www.irena.org/wind

# data[].attributes.attachment_link.description
Wind is used to produce electricity by converting the kinetic energy of air in motion into electricity. In modern wind turbines, wind rotates the rotor blades, which convert kinetic energy into rotational energy. This rotational energy is transferred by a shaft which to the generator, thereby produc…

# data[].attributes.body
Tides are easily predictable.

# data[].attributes.headline
cannot store for more than 6 months without adding different chemicals

# data[].attributes.subject
cannot store for more than 6 months without adding different chemicals

# data[].attributes.body
https://www.sciencedirect.com/topics/earth-and-planetary-sciences/biodiesel

# data[].attributes.attachment_link.title
Biodiesel - an overview | ScienceDirect Topics

# data[].attributes.attachment_link.description
Biodiesel is the monoalkyl esters of long-chain fatty acids derived from renewable feedstocks, such as vegetable oil or animal fats, for use in engine.

# data[].attributes.attachment_link.readable_text
Nuclear energy is the energy in the nucleus, or core, of an atom. Atoms are tiny units that make up all matter in the universe, and energy is what holds the nucleus together. There is a huge amount of energy in an atom's dense nucleus. In fact, the power that holds the nucleus together is officially called the "strong force."

Nuclear energy can be used to create electricity, but it must first be released from the atom. In the process of nuclear fission, atoms are split to release that energy.

A nuclear reactor, or power plant, is a series of machines that can control nuclear fission to produce electricity. The fuel that nuclear reactors use to produce nuclear fission is pellets of the element uranium. In a nuclear reactor, atoms of uranium are forced to break apart. As they split, the atoms release tiny particles called fission products. Fission products cause other uranium atoms to split, starting a chain reaction. The energy released from this chain reaction creates heat.

The heat created by nuclear fission warms the reactor's cooling agent. A cooling agent is usually water, but some nuclear reactors use liquid metal or molten salt. The cooling agent, heated by nuclear fission, produces steam. The steam turns turbines, or wheels turned by a flowing current. The turbines drive generators, or engines that create electricity.

Rods of material called nuclear poison can adjust how much electricity is produced. Nuclear poisons are materials, such as a type of the element xenon, that absorb some of the fission products created by nuclear fission. The more rods of nuclear poison that are present during the chain reaction, the slower and more controlled the reaction will be. Removing the rods will allow a stronger chain reaction and create more electricity.

As of 2011, about 15 percent of the world's electricity is generated by nuclear power plants. The United States has more than 100 reactors, although it creates most of its electricity from fossil fuels and hydroelectric energy. Nations such as Lithuania, France, and Slovakia create almost all of their electricity from nuclear power plants.

Nuclear Food: Uranium

Uranium is the fuel most widely used to produce nuclear energy. That's because uranium atoms split apart relatively easily. Uranium is also a very common element, found in rocks all over the world. However, the specific type of uranium used to produce nuclear energy, called U-235, is rare. U-235 makes up less than one percent of the uranium in the world.

Although some of the uranium the United States uses is mined in this country, most is imported. The U.S. gets uranium from Australia, Canada, Kazakhstan, Russia, and Uzbekistan. Once uranium is mined, it must be extracted from other minerals. It must also be processed before it can be used.

Because nuclear fuel can be used to create nuclear weapons as well as nuclear reactors, only nations that are part of the Nuclear Non-Proliferation Treaty (NPT) are allowed to import uranium or plutonium, another nuclear fuel. The treaty promotes the peaceful use of nuclear fuel, as well as limiting the spread of nuclear weapons.

A typical nuclear reactor uses about 200 tons of uranium every year. Complex processes allow some uranium and plutonium to be re-enriched or recycled. This reduces the amount of mining, extracting, and processing that needs to be done.

Nuclear Energy and People

Nuclear energy produces electricity that can be used to power homes, schools, businesses, and hospitals. The first nuclear reactor to produce electricity was located near Arco, Idaho. The Experimental Breeder Reactor began powering itself in 1951. The first nuclear power plant designed to provide energy to a community was established in Obninsk, Russia, in 1954.

Building nuclear reactors requires a high level of technology, and only the countries that have signed the Nuclear Non-Proliferation Treaty can get the uranium or plutonium that is required. For these reasons, most nuclear power plants are located in the developed world.

Nuclear power plants produce renewable, clean energy. They do not pollute the air or release greenhouse gases. They can be built in urban or rural areas, and do not radically alter the environment around them.

The steam powering the turbines and generators is ultimately recycled. It is cooled down in a separate structure called a cooling tower. The steam turns back into water and can be used again to produce more electricity. Excess steam is simply recycled into the atmosphere, where it does little harm as clean water vapor.

However, the byproduct of nuclear energy is radioactive material. Radioactive material is a collection of unstable atomic nuclei. These nuclei lose their energy and can affect many materials around them, including organisms and the environment. Radioactive material can be extremely toxic, causing burns and increasing the risk for cancers, blood diseases, and bone decay.

Radioactive waste is what is left over from the operation of a nuclear reactor. Radioactive waste is mostly protective clothing worn by workers, tools, and any other material that have been in contact with radioactive dust. Radioactive waste is long-lasting. Materials like clothes and tools can stay radioactive for thousands of years. The government regulates how these materials are disposed of so they don't contaminate anything else.

Used fuel and rods of nuclear poison are extremely radioactive. The used uranium pellets must be stored in special containers that look like large swimming pools. Water cools the fuel and insulates the outside from contact with the radioactivity. Some nuclear plants store their used fuel in dry storage tanks above ground.

The storage sites for radioactive waste have become very controversial in the United States. For years, the government planned to construct an enormous nuclear waste facility near Yucca Mountain, Nevada, for instance. Environmental groups and local citizens protested the plan. They worried about radioactive waste leaking into the water supply and the Yucca Mountain environment, about 130 kilometers (80 miles) from the large urban area of Las Vegas, Nevada. Although the government began investigating the site in 1978, it stopped planning for a nuclear waste facility in Yucca Mountain in 2009.

Chernobyl

Critics of nuclear energy worry that the storage facilities for radioactive waste will leak, crack, or erode. Radioactive material could then contaminate the soil and groundwater near the facility. This could lead to serious health problems for the people and organisms in the area. All communities would have to be evacuated.

This is what happened in Chernobyl, Ukraine, in 1986. A steam explosion at one of the power plants four nuclear reactors caused a fire, called a plume. This plume was highly radioactive, creating a cloud of radioactive particles that fell to the ground, called fallout. The fallout spread over the Chernobyl facility, as well as the surrounding area. The fallout drifted with the wind, and the particles entered the water cycle as rain. Radioactivity traced to Chernobyl fell as rain over Scotland and Ireland. Most of the radioactive fallout fell in Belarus.

The environmental impact of the Chernobyl disaster was immediate. For kilometers around the facility, the pine forest dried up and died. The red color of the dead pines earned this area the nickname the Red Forest. Fish from the nearby Pripyat River had so much radioactivity that people could no longer eat them. Cattle and horses in the area died.

More than 100,000 people were relocated after the disaster, but the number of human victims of Chernobyl is difficult to determine. The effects of radiation poisoning only appear after many years. Cancers and other diseases can be very difficult to trace to a single source.

Future of Nuclear Energy

Nuclear reactors use fission, or the splitting of atoms, to produce energy. Nuclear energy can also be produced through fusion, or joining (fusing) atoms together. The sun, for instance, is constantly undergoing nuclear fusion as hydrogen atoms fuse to form helium. Because all life on our planet depends on the sun, you could say that nuclear fusion makes life on Earth possible.

Nuclear power plants do not have the capability to safely and reliably produce energy from nuclear fusion. It's not clear whether the process will ever be an option for producing electricity. Nuclear engineers are researching nuclear fusion, however, because the process will likely be safe and cost-effective.

# data[].attributes.attachment_link.title
Nuclear Energy | National Geographic Society

# data[].attributes.attachment_link.description
Nuclear energy is the energy in the nucleus, or core, of an atom. Atoms are tiny units that make up all matter in the universe, and energy is what holds the nucleus together. There is a huge amount of energy in an atom's dense nucleus.

# data[].attributes.body
While nuclear power remains a great subject of debate as to how safe it is to use, and whether or not it is really energy efficient when you take into account the waste it produces – the fact is it remains one of the major renewable sources of energy available to the world.

# data[].attributes.body
Hydropower, or hydroelectric power, is a renewable source of energy that generates power by using a dam or diversion structure to fix the natural flow of a river or other body of water.

# data[].attributes.attachment_link.readable_text
HOW DO WE GET ENERGY FROM WATER?

Hydropower, or hydroelectric power, is a renewable source of energy that generates power by using a dam or diversion structure to alter the natural flow of a river or other body of water. Hydropower relies on the endless, constantly recharging system of the water cycle to produce electricity, using a fuel-water-that is not reduced or eliminated in the process. There are many types of hydropower facilities, though they are all powered by the kinetic energy of flowing water as it moves downstream. Hydropower utilizes turbines and generators to convert that kinetic energy into electricity, which is then fed into the electrical grid to power homes, businesses, and industries.

HOW EXACTLY IS ELECTRICITY GENERATED AT HYDROPOWER PLANTS?

Because hydropower uses water to generate electricity, plants are usually located on or near a water source. The energy available from the moving water depends on both the volume of the water flow and the change in elevation-also known as the head-from one point to another. The greater the flow and the higher the head, the more the electricity that can be generated.

At the plant level, water flows through a pipe-also known as a penstock-and then spins the blades in a turbine, which, in turn, spins a generator that ultimately produces electricity. Most conventional hydroelectric facilities operate this way, including run-of-the-river systems and pumped storage systems.

# data[].attributes.attachment_link.description
Hydropower, or hydroelectric power, is a renewable source of energy that generates power by using a dam or diversion structure to alter the natural flow of a river or other body of water.

# data[].attributes.attachment_link.description
Our top clean energy source is nuclear power. Available 24/7, nuclear supports our climate goals, national security and leadership in innovation.

# data[].attributes.body
https://www.nei.org/advantages

# data[].attributes.attachment_link.description
Nuclear energy powers our way of life while barely leaving a trace. It holds the key to our high-tech future and drives us to a brighter world.

# data[].attributes.attachment_link.readable_text
Tidal energy is created using the movement of our tides and oceans, where the intensity of the water from the rise and fall of tides is a form of kinetic energy. Tidal power surrounds gravitational hydropower, which uses the movement of water to push a turbine to generate electricity. The turbines are likened to wind turbines, except they are positioned underwater.

The weather in the Scottish Isles allows for the largest production of tidal power in the UK - did you know that the latest figures have shown that Scotland produced enough energy from wind farms in the first half of 2019 to power up to 4.47m homes? Nearly double the amount it has. Across the world, tidal energy is improving, as engineers develop new concepts and technologies to increase energy demand. Here in Northern Ireland, in 2007 at Strangford Lough, the world's first-ever commercial-scale tidal power station (SeaGen) was developed, consisting of two 600kW turbines.

Tidal can be harnessed in three different ways; tidal streams, barrages, and lagoons. However, as we are still waiting on tidal energy to become more economical, there are a few alternative ways that we can capture tidal energy, highlighted in the video below.

What are the advantages of tidal energy?

Predictable energy output - tides are predictable and constant, thanks to gravitational forces. Only needing to assess the low or high tide, makes it easier for engineers to design efficient systems.

As technology advances for tidal, it will get increasingly cheaper and efficient.

Protects coastal flooding due to the stability of the rock armour under different design conditions. Tidal lagoons can withstand 1 in 500 storm surges and waves a year.

Equipment and facilities of tidal power can last a lot longer and be more cost-competitive than other renewable technologies. With an asset life of 120 years, developments are made for future increases in sea-level.

What is stopping us from making the most of tidal energy?

It is currently expensive to construct tidal power plants as they require high capital investments.

Environmental issues such as habitat change, particularly with tidal barrages.

Maintaining and repairing equipment can be a challenge.

Limited energy demand. Powerful tides only happen normally 10 hours out of each day, this means the tidal energy storage capacity must be developed.

Difficult to provide tidal energy to coastal communities, as the energy produced by the tides is often a long distance from where the electricity will be used inland.

Large-scale tidal power

Currently, the Sihwa Lake project remains the world's largest tidal power station in operation, located on the west coast of South Korea. The 254 MW Sihwa project, consisting of 10 water turbine generators, has enough power to support the domestic needs of a city with a population of 500,000 people. "The 552.7 GWh of electricity generated from Sihwa tidal power plant is equivalent to 862,000 barrels of oil, or 315,000 tons of CO₂ - the amount produced by 100,000 cars annually." Around 160 million tonnes of water flows in and out of the floodgate and waterwheel, which is responsible for half of the total water quantity in Sihwa Lake. The ongoing circulation of water between the lake and the outer sea during the energy generation process has improved the water quality. With limited energy resources, South Korea is looking to transition to tidal power, to provide an alternative to fossil fuels and develop emission-free clean energy.

What is next for tidal energy?

Tidal energy has the potential to offer all the power we need, eliminating the need for fossil fuels. As stated by Simec Atlantis Energy; "The tide moves a huge amount of water, twice a day. Harnessing it could provide a great deal of energy - around 20% of Britain's needs"

However, as tidal technology has only been available for a few decades, many challenges remain. British companies and Universities are currently developing a new wave of technology, supported by grants from the £50m Marine Renewables Deployment Fund. Almost 10 years ago, the South West Regional Development Agency installed the Wavehub, the most technologically sophisticated open-access site for testing offshore renewable technologies, 16km off the Cornwall coast. Another company also making a splash in the United Kingdom, is the European Marine Energy Centre(EMEC) in Orkney.

There are definite opportunities associated with tidal and wave stream technologies, which could offer potential solutions in combatting against the world's climate crisis, whilst achieving the UK's net-zero target in 2050.

Why not read more about harnessing water to generate energy in our Hydropower blog, or learn about the challenges involved in installing micro-hydropower in water networks in our REDAWN EU project blog.

# data[].attributes.attachment_link.title
Everything you need to know about Tidal Energy - Action Renewables

# data[].attributes.attachment_link.description
Tidal energy is created using the movement of our tides and oceans, where the intensity of the water from the rise and fall of tides is a form of kinetic energy. Tidal power surrounds gravitational hydropower, which uses the movement of water to push a turbine to generate electricity.

# data[].attributes.body
https://nuclear.gepower.com/company-info/nuclear-power-basics#:~:text=Nuclear%20power%20is%20a%20clean,atoms%20in%20a%20nuclear%20reactor.

# data[].attributes.attachment_link.readable_text
Nuclear power is a clean and efficient way of boiling water to make steam, which turns turbines to produce electricity.

Nuclear power plants use low-enriched uranium fuel to produce electricity through a process called fission-the splitting of uranium atoms in a nuclear reactor. Uranium fuel consists of small, hard ceramic pellets that are packaged into long, vertical tubes. Bundles of this fuel are inserted into the reactor.

A single uranium pellet, slightly larger than a pencil eraser, contains the same energy as a ton of coal, 3 barrels of oil, or 17,000 cubic feet of natural gas. Each uranium fuel pellet provides up to five years of heat for power generation. And because uranium is one of the world's most abundant metals, it can provide fuel for the world's commercial nuclear plants for generations to come.

Nuclear power offers many benefits for the environment as well. Power plants don't burn any materials so they produce no combustion by-products. Additionally, because they don't produce greenhouse gases, nuclear plants help protect air quality and mitigate climate change.

When it comes to efficiency and reliability, no other electricity source can match nuclear. Nuclear power plants can continuously generate large-scale, around-the-clock electricity for many months at a time, without interruption.

Currently, nuclear energy supplies 12 percent of the world's electricity and approximately 20 percent of the energy in the United States. As of 2018, a total of 30 countries worldwide are operating 450 nuclear reactors for electricity generation.

For decades, GE and Hitachi have been at the forefront of nuclear technology, setting the industry benchmark for reactor design and construction and helping utility customers operate their plants safely and reliably.

# data[].attributes.attachment_link.title
What is Nuclear Power and Energy? | GE Hitachi Nuclear Energy

# data[].attributes.attachment_link.description
Nuclear power is a clean and efficient way of boiling water to make steam, which turns turbines to produce electricity. Nuclear power plants use low-enriched uranium fuel to produce electricity through a process called fission-the splitting of uranium atoms in a nuclear reactor.

# data[].attributes.attachment_link.title
Tidal power - U.S. Energy Information Administration (EIA)

# data[].attributes.attachment_link.description
Tidal power for electricity generation and locations of tidal power facilities around the world.

# data[].attributes.attachment_link.readable_text
The amount of sunlight that strikes the earth's surface in an hour and a half is enough to handle the entire world's energy consumption for a full year. Solar technologies convert sunlight into electrical energy either through photovoltaic (PV) panels or through mirrors that concentrate solar radiation. This energy can be used to generate electricity or be stored in batteries or thermal storage.

Below, you can find resources and information on the basics of solar radiation, photovoltaic and concentrating solar-thermal power technologies, electrical grid systems integration, and the non-hardware aspects ( soft costs) of solar energy. You can also learn more about how to go solar and the solar energy industry. In addition, you can dive deeper into solar energy and learn about how the U.S. Department of Energy Solar Energy Technologies Office is driving innovative research and development in these areas.

Solar Energy 101

Solar radiation is light - also known as electromagnetic radiation - that is emitted by the sun. While every location on Earth receives some sunlight over a year, the amount of solar radiation that reaches any one spot on the Earth's surface varies. Solar technologies capture this radiation and turn it into useful forms of energy.

# data[].attributes.attachment_link.description
Learn solar energy technology basics: solar radiation, photovoltaics (PV), concentrating solar-thermal power (CSP), grid integration, and soft costs.

# data[].attributes.body
Using Solar Electricity at Home | Department of Energy

https://www.energy.gov › energysaver › using-solar-electr...

# data[].attributes.attachment_link.readable_text
Solar energy is a powerful source of energy that can be used to heat, cool, and light homes and businesses.

More energy from the sun falls on the earth in one hour than is used by everyone in the world in one year. A variety of technologies convert sunlight to usable energy for buildings. The most commonly used solar technologies for homes and businesses are solar photovoltaics for electricity, passive solar design for space heating and cooling, and solar water heating.

Businesses and industry use solar technologies to diversify their energy sources, improve efficiency, and save money. Energy developers and utilities use solar photovoltaic and concentrating solar power technologies to produce electricity on a massive scale to power cities and small towns.

Learn more about the following solar technologies:

Converts sunlight directly into electricity to power homes and businesses.

Provides light and harnesses heat from the sun to warm our homes and businesses in winter.

Harnesses heat from the sun to provide hot water for homes and businesses.

Uses solar energy to heat or cool commercial and industrial buildings.

Harnesses heat from the sun to provide electricity for large power stations.

Additional Resources

For more information about solar energy, visit the following resources:

Solar Energy Technology Basics
U.S. Department of Energy Office of Energy Efficiency & Renewable Energy
U.S. Department of Energy Solar Decathlon
Energy Kids Solar Basics
U.S. Energy Information Administration Energy Kids

Clean Energy Education and Professional Development
U.S. Department of Energy's Office of Energy Efficiency and Renewable Energy

# data[].attributes.attachment_link.description
Solar energy is a powerful source of energy that can be used to heat, cool, and light homes and businesses. More energy from the sun falls on the earth in one hour than is used by everyone in the world in one year. A variety of technologies convert sunlight to usable energy for buildings.

# data[].attributes.attachment_link.readable_text
Energy from the sun

The sun has produced energy for billions of years and is the ultimate source for all of the energy sources and fuels that we use. People have used the sun's rays (solar radiation) for thousands of years for warmth and to dry meat, fruit, and grains. Over time, people developed technologies to collect solar energy for heat and to convert it into electricity.

Source: NASA

Solar thermal (heat) energy

A solar oven (a box for collecting and absorbing sunlight) is an example of a simple solar energy collection device. In the 1830s, British astronomer John Herschel used a solar oven to cook food during an expedition to Africa. People now use many different technologies for collecting and converting solar radiation into useful heat energy for a variety of purposes.

Water for homes, buildings, or swimming pools

Air inside homes, greenhouses, and other buildings

Fluids in solar thermal power plants

Solar photovoltaic systems

Solar photovoltaic (PV) devices, or solar cells, convert sunlight directly into electricity. Small PV cells can power calculators, watches, and other small electronic devices. Larger solar cells are grouped in PV panels, and PV panels are connnected in arrays that can produce electricity for an entire house. Some PV power plants have large arrays that cover many acres to produce electricity for thousands of homes.

Benefits and limitations

Solar energy systems do not produce air pollutants or carbon dioxide.

Solar energy systems on buildings have minimal effects on the environment.

The availability and amount of sunlight that arrives at the earth's surface varies depending on time of day, location, season of the year, and weather conditions.

The amount of sunlight reaching a square foot of the earth's surface is relatively small, so a large surface area is necessary to absorb or collect enough energy to be useful.

Last reviewed: December 27, 2022

# data[].attributes.attachment_link.description
An introduction to solar energy and types of solar energy conversion technologies including solar thermal and solar photovoltaics (PV).

# data[].attributes.attachment_link.readable_text
Fusion energy is perhaps the longest of long shots. To build a fusion reactor is essentially to create an artificial star. Scientists have been studying the physics of fusion for a century and working to harness the process for decades. Yet almost every time researchers make an advance, the goal posts seem to recede even farther in the distance.

Still, the enormous potential of fusion makes it hard to ignore. It's a technology that could safely provide an immense and steady torrent of electricity, harnessing abundant fuel made from seawater to ignite the same reaction that powers the sun. It would produce no greenhouse gases and minimal waste compared to conventional energy sources.

With global average temperatures rising and energy demands growing, the quest for fusion is timelier than ever: It could help solve both these problems at the same time. But despite its promise, fusion is often treated as a scientific curiosity rather than a must-try moonshot - an actual, world-changing solution to a massive problem.

The latest episode of Unexplainable, Vox's podcast about unsolved mysteries in science, asks scientists about their decades-long pursuit of a star in a bottle. They talk about their recent progress and why fusion energy remains such a challenge. And they make the case for not only continuing fusion research, but aggressively expanding and investing in it - even if it won't light up the power grid anytime soon.

With some of the most powerful machines ever built, scientists are trying to refine delicate, subatomic mechanics to achieve a pivotal milestone: getting more energy out of a fusion reaction than they put in. Researchers say they are closer than ever.

Fusion is way more powerful than any other energy source we have

Nuclear fission is what happens when big atoms like uranium and plutonium split apart and release energy. These reactions powered the very first atomic bombs, and today they power conventional nuclear reactors.

Fusion is even more potent. It's what happens when the nuclei of small atoms stick together, fusing to create a new element and releasing energy. The most common form is two hydrogen atoms fusing to create helium.

The reason that fusion generates so much energy is that the new element weighs a smidgen less than the sum of its parts. That tiny bit of lost matter is converted into energy according to Albert Einstein's famous formula, E = mc ². "E" stands for energy and "m" stands for mass.

The last part of the formula is "c," a constant that measures the speed of light - 300,000 kilometers per second, which is then squared. So there's an enormous multiplier for matter that's converted into energy, making fusion an extraordinarily powerful reaction.

These basics are well understood, and researchers are confident that it's possible to harness it in a useful way, but so far, it's been elusive.

"It's a weird thing, because we absolutely know that the fundamental theory works. We've seen it demonstrated," said Carolyn Kuranz, a plasma physicist at the University of Michigan. "But trying to do it in a lab has provided us a lot of challenges."

For a demonstration, one only has to look up at the sun during the day (but not directly, because you'll hurt your eyes). Even from 93 million miles away, our nearest star generates enough energy to heat up the Earth through the vacuum of space.

But the sun has an advantage that we don't have here on Earth: It is very, very big. One of the difficulties with fusion is that atomic nuclei - the positively charged cores of atoms - normally repel each other. To overcome that repulsion and spark fusion, you have to get the atoms moving really fast in a confined space, which makes collisions more likely.

A star like the sun, which is about 333,000 times the mass of Earth, generates gravity that accelerates atoms toward its center - heating them up, confining them, and igniting fusion. The fusion reactions then provide the energy to speed up other atomic nuclei and trigger even more fusion reactions.

What makes fusion energy so tricky

Imitating the sun on Earth is a tall order. Humans have been able to trigger fusion, but in ways that are uncontrolled, like in thermonuclear weapons (sometimes called hydrogen bombs). Fusion has also been demonstrated in laboratories, but under conditions that consume far more energy than the reaction produces. The reaction generally requires creating a high-energy state of matter known as plasma, which has quirks and behaviors that scientists are still trying to understand.

To make fusion useful, scientists need to trigger it in a controlled way that yields far more energy than they put in. That energy can then be used to boil water, spin a turbine, or generate electricity. Teams around the world are studying different ways to accomplish this, but the approaches tend to fall into two broad categories.

One involves using magnets to contain the plasma. This is the approach used by ITER, the world's largest fusion project, currently under construction in southern France.

The other category involves confining the fusion fuel and compressing it in a tiny space with the aid of lasers. This is the approach used by the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory in California.

Replicating a star requires doing this research at massive scales, so fusion experiments often involve the most powerful scientific instruments ever built. ITER's central solenoid, for example, can generate a magnetic force strong enough to hoist an aircraft carrier 6 feet out of the water.

Building hardware to withstand these extreme conditions is its own scientific and engineering challenge. Managing such massive experiments has also been a struggle. ITER started with an initial cost estimate of 6.6 billion euros, which has since more than tripled. It began construction in 2007 and its first experiments are set to begin in 2025.

An upside to the intricacy of fusion reactions is that it is almost impossible to cause a runaway reaction or meltdown of the sort that have devastated fission power plants like Chernobyl. If a fusion reactor is disrupted, the reaction rapidly fizzles out. In addition, the main "waste" product of hydrogen fusion is helium, an inert gas. The process can induce some reactor materials to become radioactive, but the radioactivity is much lower, and the quantity of hazardous waste is far smaller, compared to conventional nuclear power plants. So nuclear fusion energy could become one of the safest sources of electricity.

For policymakers, investing in an expensive research project that may not yield fruit for decades, if at all, is a tough sell. Scientific progress doesn't always keep up with political timelines: A politician who greenlights a fusion project might not even live to see it become a viable energy source - so they certainly won't be able to brag about their success by the time the next election rolls around.

In the United States, funding for fusion research has been erratic over the years and far below the levels government analysts say is needed to make the technology a reality. The US Department of Energy currently spends about $500 million on fusion per year, compared to almost $1 billion on fossil fuel energy and $2.7 billion on renewables. Investment in fusion seems even tinier next to other major programs like NASA ($23 billion) or the military ($700 billion).

So from its basic physics to government budgets, fusion energy has a lot working against it.

Fusion energy should be treated as a solution, not just an experiment

Working in fusion's favor, however, are scientists and engineers who think it's not just possible, but inevitable.

"I'm a true believer. I do think we can solve this problem," said Troy Carter, a plasma physicist at the University of California Los Angeles. "It will take time, but the real issue is getting the resources brought to bear on these issues."

Investors are also getting in the game, placing billion-dollar bets on private startup companies developing their own fusion strategies.

The journey toward fusion has yielded benefits for other fields, particularly in plasma physics, which is used extensively in manufacturing semiconductors for electronics. "Plasma processing is one of the things that make your iPhones possible," said Kathryn McCarthy, a fusion researcher at Oak Ridge National Laboratory.

And despite the hurdles, there have been some real advances. Researchers at NIF reported last summer that they achieved their best results yet - 1.3 megajoules of output from 1.9 megajoules of input - putting them closer than ever to energy-positive fusion. "We're on the threshold of ignition," said Tammy Ma, a plasma physicist at NIF.

To break out of its rut, fusion will need to be more than a science experiment. Just as space exploration is more than astronomy, fusion is much more than physics. It should be a leading tool in the fight against the world's most urgent problems, from climate change to lifting people out of poverty.

Increasing energy access is closely linked to improving health, economic growth, and social stability. Yet close to a billion people still don't have electricity and many more only have intermittent power, so there is an urgent humanitarian need for more energy.

At the same time, the window for limiting climate change is slamming shut, and electricity and heat production remain the dominant sources of heat-trapping gases in the atmosphere. To meet one of the goals of the Paris climate agreement - limiting warming to less than 1.5 degrees Celsius this century - the world needs to cut greenhouse gas emissions by half or more by 2030, according to the Intergovernmental Panel on Climate Change. Many of the world's largest greenhouse gas emitters are also aiming to zero out their contributions to climate change by the middle of the century. Making such drastic cuts in emissions means phasing out fossil fuels as quickly as possible and rapidly deploying much cleaner sources of energy.

The technologies of today may not be up to the task of resolving the tension between the need for more energy and the need to reduce carbon dioxide emissions. A problem like climate change is an argument for placing bets on all kinds of far-reaching energy solutions, but fusion may be the technology with the highest upside. And on longer time scales, closer to the 2040s and 2050s, it could be a real solution.

With more investment from governments and the private sector, scientists could speed up their pace of progress and experiment with even more approaches to fusion. In the US, where much of the research is conducted at national laboratories, this would mean convincing your representatives in Congress to get excited about fusion and ultimately to spend more money. Lawmakers can also encourage private companies to get into the game by, for example, pricing carbon dioxide emissions to create incentives for clean energy research.

The key, according to Carter, is to ensure support for fusion remains steady. "Given the level of importance here and the amount of money invested in energy, the current investment in fusion is a drop in the bucket," Carter said. "You could imagine ramping it up orders of magnitude to get the job done."

He added that funding for fusion doesn't have to cannibalize resources from other clean energy technologies, like wind, solar, and nuclear power. "We need to invest across the board," Carter said.

For now, the big fusion experiments at NIF and ITER will continue inching forward. At NIF, scientists will continue refining their process and steadily work their way up toward energy-positive fusion. ITER is scheduled to begin operation in 2025 and start hydrogen fusion experiments in 2035.

Artificial star power might not illuminate the world for decades, but the foundations have to be laid now through research, development, and deployment. It may very well become humanity's crowning achievement, more than a century in the making.

# data[].attributes.attachment_link.title
Fusion energy is a reason to be excited about the future

# data[].attributes.attachment_link.description
Fusion energy is perhaps the longest of long shots. To build a fusion reactor is essentially to create an artificial star. Scientists have been studying the physics of fusion for a century and working to harness the process for decades. Yet almost every time researchers make an advance, the goal posts seem to recede even farther in the distance.

# data[].attributes.attachment_link.title
sound energy: definition, uses, and examples - studentlesson

# data[].attributes.attachment_link.description
Today you’ll get to know the definition, uses, importance, and examples of sound energy. Sound from an air conditioning fan, an airplane taking off are

# data[].attributes.attachment_link.readable_text
Wind is the largest source of renewable energy in the United States, providing clean electricity from land and offshore to individual homes, remote farms, small communities and large cities alike.

Wind energy is old-so old that ancient Egyptians used this bountiful, blustery resource, according to the U.S. Energy Information Administration, to propel their boats down the Nile River. The first wind turbines (or windmills, as they were originally called) were made from abundant materials, such as wood or reeds, which were woven into tight blades and spun to pump water for farms, grind grain, and, eventually, power entire communities.

Today's wind turbines use sleek, modern materials to generate clean, renewable energy almost anywhere in the world.

What Is Wind Energy?

To answer this question, it's best to start with another: What is wind?

Wind is born when pockets of the Earth's craggy surface get different amounts of sun and cool or heat faster than others nearby. To balance those differences, like mixing hot and cold water in a bathtub, air moves around the world-gaining or losing speed as it dips through valleys and sprints over rivers. That creates-you guessed it-wind.

Wind can be powerful enough to whisk birds through the sky, move sailboats across the ocean, and even rip trees from the ground. In comparison to all that, pushing wind turbine blades is easy! It's that movement of the turbines that creates electricity.

Want to know how much wind energy is humming across your state? Check out NREL's wind maps on WINDExchange.

How Do Wind Turbines Work?

Wind turbines, like windmills, catch the wind's energy with propeller-like blades. These blades can have a horizontal axis, like a fan, or vertical one, like a merry-go-round. The most common design is a tall tower with three large blades on a horizontal axis. But some vertical-axis wind turbines look like eggbeaters, while others look like the windmills that populated farms a century ago.

Unlike fans, which use electricity to move air, wind turbines use moving air to generate electricity. When the wind blows, its force turns the blades, which runs a generator and creates clean electricity. But some turbine designs can produce more clean energy than others. For example, because winds can be more powerful and less volatile higher in the atmosphere, placing turbines on towers 100 feet (or 30 meters) tall-about the height of the Statue of Liberty-can help them generate more electricity. Wind turbine operators can also shift their machines to face directly into the wind-a technique called yawing.

Can't picture this? Watch the U.S. Department of Energy's wind energy animation to see wind turbines in action.

How Do We Get Our Wind Energy?

There are several ways to get power from wind energy. Wind turbines can be built on land, on lakes or in the ocean, in remote wilderness far from the power grid, within cities, or across vast plains.

One wind turbine can power an individual home or farm, but several built close together form a wind energy plant, or wind farm. Wind plants can be land-based or offshore, and they can be hybrid plants (meaning, they include other sources of energy, such as solar energy). Wind energy researchers are trying to learn how many wind turbines built in which arrangements can maximize energy production in wind plants.

Today, most grid-connected wind plants are at least 1 megawatt or larger. The biggest wind farm in the United States spans 100,000 acres (enough to cover half of New York City) and can power more than 250,000 homes.

What Are the Major Applications of Wind Energy?

Wind energy has three major applications: land-based, distributed, and offshore.

Land-Based Wind Energy Is the Most Common

The majority of turbines are installed on land. And land-based wind energy is one of the lowest-cost sources of electricity generation, as highlighted by the U.S. Department of Energy.

Researchers at NREL are categorizing wind resources on land and advancing wind turbines to more efficiently generate electricity at even lower cost.

Distributed Wind Energy Powers Remote and Local Communities

Distributed wind energy is a distributed energy resource, meaning it produces a smaller-scale unit of power. In this case, it comprises one or more wind turbines, which range from a kilowatt to several megawatts in capacity.

These typically land-based turbines operate locally to provide energy for individual buildings or small communities, though they can be connected to a power grid at the distribution level. Some wind turbines can even pop up as mobile, on-demand sources of clean power in disaster or defense scenarios.

Homeowners, farmers, businesses, and industries make use of clean, distributed wind energy to pump water (to use as drinking water, to irrigate farms, and more), to lower electric bills, and to reduce air pollution.

Distributed wind turbines are improving all the time, growing stronger, less costly, more resilient, and more efficient.

Offshore Wind Energy Is Newer but Growing

Wind turbines used in offshore wind energy can be even larger than on land, with towers one-and-a-half-times the height of the Washington Monument and blades as long as a football field (as noted in to the U.S. Department of Energy's list of 10 things you may not have known about wind energy).

These behemoths depend on strong sea breezes to spin turbines that are either anchored to the seafloor (called fixed-bottom wind turbines) or installed on platforms that float (called floating wind turbines). Offshore wind turbines can provide electricity to power ocean-based research and equipment, such as unmanned robots used for marine exploration; remote or island communities disconnected from the grid; or entire cities back on land.

The offshore wind energy industry is growing. Researchers are identifying massive amounts of potential wind energy off U.S. coastlines, and the Biden administration has set a goal to install 30 gigawatts of wind energy by 2030. That will require us to grow the offshore wind energy workforce as well as the supply chain to build and infrastructure to deploy new offshore wind farms.

The U.S. Department of Energy indicates that, as of 2022, nearly 80% of the nation's electricity is used to power our coastal and Great Lakes states, where most Americans live. So, even though offshore wind energy is a relatively new industry in the United States, it could soon provide clean, renewable electricity to many U.S. communities. America's first offshore wind farm, located off the coast of Rhode Island, powered up in December 2016. Today, many more projects are in development along the U.S. East Coast that could send power back to the grid. And, with technology advancements for floating offshore wind energy, wind farms are coming to the West Coast as well.

Why Do We Need Wind Energy?

Wind energy is one of the largest sources of clean, renewable energy in the United States, making it essential to a future carbon-free energy sector. Wind turbines do not release emissions that pollute our air or water, and they can be built with minimal impact to the environment or livelihoods of nearby residents. Farmers and ranchers, for example, can lease their land to wind farms and, because the turbines take up minimal space, continue to grow crops or raise livestock while earning a steady income.

But wind energy can be even better.

The wind energy industry is working to figure out what areas of research need more attention to expand the use of wind energy. This includes understanding how wind interacts with a turbine behind (downwind from) another one, evaluating the best ways to verify new technologies, and incorporating feedback from communities living near or using wind turbines.

Researchers are studying different materials and designs that could make wind turbine blades lighter, longer, more durable, and better at creating energy. New technologies could also make wind turbines less expensive to manufacture, install, operate, and maintain, making wind energy more accessible to more people. As a bonus, some new materials and processes could make wind turbines more reusable or recyclable, which can cut down on waste, too.

Scientists are also studying ways to limit the impact wind turbines can have on wildlife. For example, sound and light could warn birds and bats to fly around wind turbines. And even though wind turbines must be installed far enough from homes that they produce noise no louder than a refrigerator's hum, researchers have discovered ways to further reduce their noise levels. Because wind turbines are a significant source of clean energy, they lower pollution to help keep the Earth (and, therefore, its birds, bats, and humans) healthy.

Additional Resources

For more information, visit NREL's Wind Energy Research site or the following resources:

Wind Energy Basics
U.S. Department of Energy's Office of Energy Efficiency and Renewable Energy

Small Wind Electric Systems
U.S. Department of Energy's Energy Savers Program

Wind Energy Educational Resources
U.S. Department of Energy's WINDExchange Initiative

U.S. Department of Energy's WINDExchange Initiative.

# data[].attributes.attachment_link.description
Learn about the history of wind energy and how wind turbines use wind energy to generate electricity.

# data[].attributes.headline
- "renewable energy from plants and animals"

# data[].attributes.subject
- "renewable energy from plants and animals"

# data[].attributes.body
- using biomass avoids using carbon dioxide emissions from fossil fuel use

# data[].attributes.body
https://www.nrel.gov/research/re-geo-elec-production.html

# data[].attributes.attachment_link.readable_text
Geothermal power plants use steam to produce electricity. The steam comes from reservoirs of hot water found a few miles or more below the earth's surface.

Flash steam power plant with bottoming binary unit in Nevada. Photo by Dennis Schroeder, NREL

The steam rotates a turbine that activates a generator, which produces electricity. There are three types of geothermal power plants: dry steam, flash steam, and binary cycle.

Dry Steam

Dry steam power plants draw from underground resources of steam. The steam is piped directly from underground wells to the power plant where it is directed into a turbine/generator unit. There are only two known underground resources of steam in the United States:

1. The Geysers in northern California

2. Yellowstone National Park in Wyoming, where there's a well-known geyser called Old Faithful.

Since Yellowstone is protected from development, the only dry steam plants in the country are at The Geysers.

Flash Steam

Flash steam power plants are the most common and use geothermal reservoirs of water with temperatures greater than 360°F (182°C). This very hot water flows up through wells in the ground under its own pressure. As it flows upward, the pressure decreases and some of the hot water boils into steam. The steam is then separated from the water and used to power a turbine/generator. Any leftover water and condensed steam are injected back into the reservoir, making this a sustainable resource.

Binary Steam

Binary cycle power plants operate on water at lower temperatures of about 225-360°F (107-182°C). Binary cycle plants use the heat from the hot water to boil a working fluid, usually an organic compound with a low boiling point. The working fluid is vaporized in a heat exchanger and used to turn a turbine. The water is then injected back into the ground to be reheated. The water and the working fluid are kept separated during the whole process, so there are little or no air emissions.

Currently, two types of geothermal resources can be used in binary cycle power plants to generate electricity: enhanced geothermal systems (EGS) and low-temperature or co-produced resources.

Enhanced Geothermal Systems

EGS provide geothermal power by tapping into the Earth's deep geothermal resources that are otherwise not economical due to lack of water, location, or rock type. The U.S. Geological Survey estimates that potentially 500,000 megawatts of EGS resource is available in the western U.S. or about half of the current installed electric power generating capacity in the United States.

Low-Temperature and Co-Produced Resources

Low-temperature and co-produced geothermal resources are typically found at temperatures of 300F (150C) or less. Some low-temperature resources can be harnessed to generate electricity using binary cycle technology. Co-produced hot water is a byproduct of oil and gas wells in the United States. This hot water is being examined for its potential to produce electricity, helping to lower greenhouse gas emissions and extend the life of oil and gas fields.

Additional Resources

For more information about geothermal technologies, visit the following resources:
NREL's Policymakers' Guidebook for Geothermal Electricity Generation NREL Geothermal Research
Low Temperature and Coproduced Resources
U.S. Department of Energy

Enhanced Geothermal Systems
U.S. Department of Energy

# data[].attributes.attachment_link.description
Geothermal power plants use steam to produce electricity. The steam comes from reservoirs of hot water found a few miles or more below the earth's surface. The steam rotates a turbine that activates a generator, which produces electricity. There are three types of geothermal power plants: dry steam, flash steam, and binary cycle.

# data[].attributes.body
table 8,Niki, Bryce,Sophia, Ayramie,Los Angeles

# data[].attributes.body
Maryn Lakeman
Luis Cervantes
Richard Gonzales
Isaiah Edwards
City: Chicago, Illinois

# data[].attributes.body
Honolulu
Chris S
Matt T
Energy sources
Main source is Oil
Better energy sources
Solar energy, Tidal energy, and Wave energy.

# data[].attributes.headline
Table 10/ Joey B, Jax S, Caesar N/ San Diego

# data[].attributes.subject
Table 10/ Joey B, Jax S, Caesar N/ San Diego

# data[].attributes.body
-$13.3 million in relief money
- 9.3 billion gallons of water a year

# data[].attributes.body
Table 4
Joshua Reed
Pedro Salas Jr
johanna gonzalez
Gabril Casares
Atlanta Georgia

# data[].attributes.body
Andrea, Andrew, Daylen, Matthew

Baton Rouge, Louisiana

# data[].attributes.headline
Aidan Zavala, Fa'alaga Su'e, Alexis Helmer 

# data[].attributes.subject
Aidan Zavala, Fa'alaga Su'e, Alexis Helmer 

# data[].attributes.body
new York city

# data[].attributes.body
Table 9
Jacqueline Perez
Bella Emery
Lily Oclaray
Zahnder Jensen
Miami Florida