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·       Over-population

·       pollution

·       greenhouse effect

·       acid rain

·       deforestation

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choose one environmental threat and think of things you may do to help reduce or control its negative (bad) effects

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Abstract

Solar cells help us use less coal or oil when we make electricity. This way, we cause fewer problems for the environment. Most solar panels are expensive, and they cannot be used for windows because they are not transparent, so they hide your view. But solar windows can be created with special chemicals called organic colorants. These windows can catch sunlight and use its energy to make electricity, but you can still see a beautiful view through them. The windows we made are inexpensive and keep the colors of your view unchanged. Each colorless window makes 100 watts of electricity, which is enough to recharge 20 smartphones at the same time. Because we can use these cheap, colorless, solar windows everywhere, we could make a lot of clean energy!

Using Sunlight as a Clean Energy Source

A lot of people live on Earth. These people use phones, televisions, computers, and many other devices that need electricity to work. The most common way to make electricity is to burn coal, gas, or oil. Burning these fuels is a problem, because they release gases like carbon dioxide and methane when burned. These gases make our planet warmer and create other environmental problems. Because of this, many countries want to create electricity from clean energy sources, like sunlight []. To do this, we need solar panels. Typical solar panels are made with a material called silicon, which can capture sunlight. Silicon is expensive, so it is difficult to put many solar panels in poor countries. Also, silicon does not let light pass through it, so silicon solar panels cannot be used for windows, because they will hide your beautiful views ( Figure 1A).

Figure 1 - Mount Fuji is the tallest and most beautiful mountain in Japan.

Everybody loves to look at it. (A) Silicon solar panels can hide Mount Fuji because they act like mirrors. If these panels were used as windows, you would not be able to see through them. (B) When we look at Mount Fuji through a solar window made with the organic colorant β-carotene, the view through the window appears orange [2], but with the red colorants we use here, the view appears red [3].

Luckily, there are many other colored chemical substances (called colorants) that can capture sunlight. When these colored substances include carbon atoms, we call them organic colorants. You can find some organic colorants in nature. For example, chlorophyll is the colorant that gives plants their green color, and β-carotene is the colorant that makes carrots look orange. We used natural or artificial organic colorants to create colorless solar windows. The structure of our solar window is shown in Figure 2. First, we made very thin sheets of organic colorant that are 1,000 times thinner than paper [ 2, 3]. We call these sheets active layers. We must mix at least two colorants into the active layers if we want them to change sunlight into electricity. We sandwich one active layer between two other sheets, called electrodes, which catch or release from or into the active layer. Electrons are small particles which create electricity when they flow from one electrode to the other. If the two electrodes are also transparent, solar windows will be see-through ( Figure 1B). These windows make electricity from less than half of the sunlight that hits them, while they let the rest of the light pass through, so you can still see beautiful views through the solar windows.

Figure 2 - See-through solar windows contain an active layer sandwiched between two electrodes.

When sunlight hits the window, the colorants in the active layer catch photons and use their energy to create electrons that can freely move from one place to another. The electrodes show the electrons in which direction they should flow and the electron flow produces electricity.

While this may sound like an exciting breakthrough, there are two big problems with these windows. First, they eventually stop working because the oxygen in the air breaks down many organic colorants. Second, if the organic colorants do not catch all the colors of light equally, the view through the windows will look orange or red. Is it possible to make solar windows that last for a long time and that do not change the color of your view? This is what we tried to do in our research.

How Do Solar Windows Work?

To make electricity, small particles called electrons must be made to move from place to place. This flow of electrons is called an electrical current. Electrons have a negative charge, so they are usually found stuck firmly to atoms, because particles called protons within atoms have a positive charge. As you probably know, opposite charges attract each other, while similar charges repel each other. To create a flow of electricity, electrons must first be knocked free from the atoms they are attached to. Knocking the electrons free requires an input of energy. In our solar windows, the electrons are knocked free from the atoms of one colorant, let us call it colorant A, by the energy of sunlight. Once the electrons are knocked free, they are "stolen" by atoms of the other colorant, which we will call colorant B. The electron stolen by colorant B can move freely from place to place because colorant B already has electrons stuck firmly to the protons within its atom. The free electrons can now flow from one electrode to the other electrode, which creates electricity. This is the basis of creating electricity using organic solar windows...but there are a few more details you need to know.

Sunlight, like all light, is made of small particles called . Photons with different energies appear to our eyes as having different colors. For example, photons of red light have less energy than photons of blue or green light. For an electrical current to be created, the energy of the photons hitting the atoms of the colorant must be strong enough to separate the electrons from the colorant atoms. If the photons do not have enough energy to knock the electrons free, they will pass through the window without helping to produce an electrical current.

Also, as we mentioned earlier, the active layer of our solar windows is sandwiched between additional layers, called electrodes. These additional layers are important because they show the electrons in which direction they should flow. The electrodes are also the materials to which you will connect the electrical equipment that you want to power with the sunlight. For example, if you want to recharge your smartphone's battery, you will connect the battery's electrodes to the solar window's electrodes.

How Can We Make Colorless Solar Windows?

Did you know that sunlight is made of many different colors? They are the colors you see in rainbows. The three primary colors are blue, green, and red (Some people say blue, yellow, and red, but we use green in science). Remember that the colors reflect the energy level of the photons. Some of the sunlight photons that hit a solar window will have enough energy to knock electrons off colorant atoms, causing an electrical current, but some photons will not. If they do not have enough energy to knock electrons off atoms, those photons will just pass right through the window-these photons are called transmitted light, and they make up the light that allows you to see through the window! We can calculate the percentage of transmitted light (T%) as follows:

We created solar windows using two red organic colorants and then shined either red, blue, or green light on these windows to determine T% for each color of light. When we tested solar windows made only with these two red colorants, we found that T% was 20% higher for red light than for blue and green light. This is because the red photons do not have enough energy to free electrons from the atoms of the red colorants in the active layer. The extra 20% of red light passes through the window and makes the window-and the view through the window-look red. We modified the active layers to contain a third colorant that can have its electrons knocked free by red photons. By doing this, we were able to make active layers that have a T% of 60% for all three primary colors ( Figure 3A). Those active layers are colorless because they transmit all the light that human eyes can see in the same amount, which makes the T% graph look like a horizontal line.

Figure 3 - (A) When we measured the amount of transmitted light through our red windows, we found that T% was 20% higher for red light than for green or blue light (red dotted line).

When we added a third chemical that can catch red photons, T% was approximately 60% for all three colors of light and the solar window was colorless. (B) Normal windows have a T% of about 70%, so the view through our solar windows appears a little darker but its colors do not change.

However, even with the proper mix of the three primary colors, the actual T% for our solar window is about 43%, because the components in the electrode layers decrease the amount of light that is transmitted. The T% of normal windows is around 70%. This means that our solar windows will look a little darker than normal windows ( Figure 3B), but the advantage is that they can transform about 4% of the sunlight that hits them into electricity!

Can Solar Windows Make Enough Electricity?

When we calculate how much electricity we use or make, we use a unit called watts (W), which is a measure of electrical power. The power that we receive from sunlight over an area of 1 m ² is 1,000 W. Our solar windows are usually 1.9 m tall and 1.3 m wide, and they can generally change 4% of the solar power into electricity. Let us calculate how much electricity one solar window can make:

Window area: 1.9 m x 1.3 m = 2.47 m ² (let us round this up to 2.5 m ²)

Using the area, the solar power received by one window becomes: 2.5 m ² × 1,000 W/m ² = 2,500 W

Thus, the electricity made by one window is: 2,500 W × 4% = 2,500 W × 0.04 = 100 W

Flat-screen televisions use around 90 W of electricity. You can charge a phone with 5 W and a tablet with 12 W. For laptops, you need around 50 W. So, if you have 1 television, 2 laptops, 1 tablet and 2 phones in your homes, you will need: 90 W + (2 × 50 W) + 12 W + (2 × 5 W) = 212 W. With 3 solar windows, you could easily use all those electronics at the same time! But wait...what if your microwave uses 500 W? This means that 5 windows would be needed to make it work. Can we make 500 W solar windows? Right now, it is difficult to make 500 W windows that have a T% over 40%, meaning these windows would make your view quite dark. We are now testing new colorants to make 250 W windows with a T% of around 40%. With only two of these windows, we could power a 500 W microwave!

Most people usually use microwaves for 5 or 10 min each day, so there are times when our solar windows would make more electricity than is needed. Batteries can be used to store excess electrical power for later use. If we use solar windows and batteries together, we should be able to power all the electronics in our homes. The electricity stored in batteries can also be used to power our electronics at night, or when there is no sunlight.

Summary

Using active layers that contain three colorants, we were able to fabricate solar windows that transmit around 40% of the light through them without changing the colors of the view you are looking at. Each of these windows can make around 100 W and we are working on ways to make more power from a single window. The organic solar windows are cheap and do not disturb your view, which means that they can be installed everywhere to power electrical equipment. As our society is using more and more electrical power, solar windows will be a key technology to make sure we can power our modern society without causing environmental problems.

Glossary

Conflict of Interest

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

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Colorless Windows That Transform Sunlight Into Electricity

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Solar cells help us use less coal or oil when we make electricity. This way, we cause fewer problems for the environment. Most solar panels are expensive, and they cannot be used for windows because they are not transparent, so they hide your view. But solar windows can be created with special chemicals called organic colorants.

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Abstract

Solar cells use freely available sunlight to make electricity. At the present time, solar electricity does not come cheap, because solar panels are rather expensive. Now imagine that we could reduce costs by printing solar panels like we print newspapers! We can do just that with plastic solar cells. In this article, we explain the basic working principles of these novel plastic solar cells and then show how a stunning threefold increase in solar energy efficiency can be achieved by including a special additive to the printing ink. The function of such a special additive seems almost magical, but as scientists we know that true magic is really rare and we simply had to find out why and how it works. That was the subject of our recent investigations and in this article we describe how we divulged the secret of the special additive.

Cheap Solar Electricity

While you are reading this article, your computer is using electricity. Where does this electricity come from? In 2013, around 67% of the electricity used in the U.S. was generated by burning coal or natural gas []. What if the supply of coal and natural gas runs out? And what about the pollution and climate change caused by burning gas and coal? There is a much friendlier source of energy: the sun! Best of all, it is free! The sun always shines and provides energy to the earth in the form of light, even on cloudy days. Solar panels convert this light into electricity, but solar panels are still pretty expensive. If solar panels were less expensive, we could use the sun to its full potential and have very cheap electricity!

Printing Plastic Solar Cells

Scientists recently found a new way to make solar panels: by printing them! Most people think about printing things like books, but we can also use a special kind of printers to print objects made out of plastics. Plastics are made of , which are very long molecules. Under a very strong microscope, polymers look like cooked spaghetti, but, in fact, they are a million times smaller. To print plastics, you simply replace the cartridge in your printer at home with "plastic ink." The plastic ink is a combination of two polymers dissolved in a liquid. When printed, the liquid dries and the two polymers form a thin film. For solar cells, we use a special type of polymer that can convert sunlight into electricity.

Plastic solar cells can be printed on large rolls of flexible foil. Recently, 100 m-long solar panels were printed []. Using these cheap solar panels, only around 1.5% of the energy in the sunlight is converted to electricity. This efficiency is still low compared to the expensive solar panels you can buy now, which can convert 15-20% of the sun's energy into electricity. But the future looks bright. In laboratories around the world, small plastic solar cells are already being made with much higher efficiencies, up to about 12% []. One of the tricks to increase the efficiency is adding a special to the plastic ink before printing. This special additive was found by accident [], but if we want to improve the efficiency of the plastic solar panels even further, we need to know why this special additive works. Understanding how plastic solar cells work is not easy. Many scientists have worked on this topic for years. As background, we explain the most important findings in the next two paragraphs, but if you feel that you are more eager to learn about the secrets of the special additive you can skip these paragraphs and read about our investigations and our results further on.

How do Plastic Solar Cells Change Light into Electricity?

To answer this important question, we have to look how plastic solar cells are made. Plastic solar cells consist of a plastic layer on glass or a flexible foil. In the lab, we use glass plates with a transparent electric contact [the positive (+) pole]. On top of this contact, we put the ink for the , which is the part of the solar cell that converts sunlight to electricity. This ink contains two polymers, a long green one and a shorter red one. The polymers form a mixed layer, as shown in Figure 1. On top of that layer, we put a metal layer, which functions as the negative (−) pole. We then turn the whole stack of layers upside down such that sunlight can shine through the glass into the active layer.

The drawn structure of red and green polymers in Figure 1 is exactly what we want! There is a lot of , or area of contact, between the two polymers. This is necessary, because sunlight creates electrical charges only at the areas where the two polymers are in contact. When the light is absorbed (the yellow star), positive (+) and negative (−) electrical charges are generated. Normally, the + and − attract each other and the energy is lost. In plastic solar cells, the red and green polymers make sure the charges can be separated. The positive and negative charges then move to the + and − poles. Now, light is converted to moving charges, which is electricity! Think about how useful this is - we use free sunlight and two cheap plastics to make electrical energy!

Can we See These Small Polymers?

The green and red polymers are so small that we cannot see them easily, even when using a normal microscope. But we can see them with an , which does not use light, but electrons to "look" at the solar cells. In Figure 2, we show electron microscopic images of real plastic solar cells. These are images looking down on the active layer. The two polymers show up as dark and bright areas and not as red and green because electrons are "colorblind." On the left, a poorly working plastic solar cell is shown. The large droplets create very little interface and the efficiency is low: 1.5%. On the right, a much better plastic solar cell is shown. The structure between dark and bright areas is now so small that it is actually hard to see, but it means that there is a lot of interface. This allows for more charges to be made and triples the efficiency to over 5%. These solar cells are still not the best, but they can help us to understand how plastic solar cells work.

The Special Additive

How did we go from the bad solar cell in the left image to a good solar cell in the right image of Figure 2? The "magic" trick is to use a special additive while making the active layer. The additive is a slowly drying liquid, which is added to the ink in a small amount. This smart trick was first shown in 2007 [ 4], but nobody understood exactly how it works. Let us first have a look what it does and then try to see if we can understand why. The active layers are made by a process called the ink, as shown in Figure 3. Spin coating is a technique to make thin films from an ink. The regular spin coating process is shown on the top row of Figure 3. A drop of ink that contains the green and red polymers in a liquid is put on a glass plate. By very fast rotation, a thin wet film forms that dries within 1 s by evaporating the liquid. While drying, the red polymer forms large droplets, which cause the poor performance. The bottom row shows the same spin coating process after the additive is added to the ink. Now, drying takes longer, about 5 s. As you see, no droplets are formed when using the special additive.

A New Experimental Setup Solved the Mystery

To untangle the mystery of the role of the special additive in creating a good solar cell, we set out to study in detail how the active layer dries. To study this drying process during the spin coating process, we had to build a new experimental setup. In this setup, we shine a laser on the spinning glass plate. The reflection of the laser changes when the droplets are formed. In this way, we found that without additive the large droplets form in a late stage of the drying process, and even later, the green polymer changes color! To understand what happens when the color changes, we recall that the green component is a long polymer. We know that long polymers can fold up, similar to how a snake curls up. The folding makes the green polymers change their color to dark green. Using our special setup, we determined the time at which the color changes and the folding happens. We discovered that the effect of the special additive is to make the green polymer fold earlier than it does without the additive, and even before the droplets would normally form! The reason is that the additive and the green polymer do not like each other very much. As a result, the green polymer folds up when it "feels" the additive. Surprisingly, we saw that once the green polymer folds, the red polymer does not form droplets. The folding of the green polymer holds back droplet formation and results in better mixed layers. The mystery is solved! A diagram of the new insights is shown in Figure 4.

Summing Up and Looking Ahead

Plastic solar cells have a huge potential because they can be printed cheaply on large flexible foils. Their efficiency still needs improvement, but can be improved threefold by adding a special additive to the printer ink. Since this additive is very useful, we wanted to understand how it works. With a new experimental setup designed to study the drying of the ink, we found that the special additive controls folding of one of the two polymers. The folding prevents large droplets and increases the amount of interface between the two polymers in the active layer. The interface is very important the efficient conversion of sunlight into electricity. In the past, solar cells were optimized by lots of hard lab work and you had to be lucky to make a good cell. Now, because we understand the process of the drying, we can think of even more clever tricks to optimize these solar cells! In the future, this will hopefully lead to cheap and efficient electricity production from printed solar panels!

You can now try to answer these questions:

1. What is the advantage of plastic solar cells compared to existing solar cells?

2. What is the main problem with plastic solar cells?

3. Why is the additive a smart idea?

4. How does this research make solar cells more accessible in the future?

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Plastic Solar Cells: Understanding the Special Additive

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Solar cells use freely available sunlight to make electricity. At the present time, solar electricity does not come cheap, because solar panels are rather expensive. Now imagine that we could reduce costs by printing solar panels like we print newspapers! We can do just that with plastic solar cells.

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Abstract

The oceans represent almost 70% of the surface of our planet, and they are in constant movement through waves, tides, and currents. These movements are formed differently: waves develop because of the action of the wind; tides because of the moon and the sun, and currents because of differences in water temperature and the rotation of the planet. Ocean movements bring food and oxygen to the plants and animals that live in the oceans and on the coasts. Waves and tides also help shape the coastline by erosion and accumulation of sand. Ocean movement is also important for humans: we have fun swimming in the waves, the tides help with fishing, and the currents are useful for moving ships across the ocean. This unending movement of the ocean can also be used to produce clean, renewable electric power.

The Ocean As a Battery?

More than 70% of the surface of our planet is covered by water. Of this, most water is found in the oceans and only 2% is freshwater in lakes, rivers, and ice. There are almost 200 countries in the world, and just over 150 have access to the sea. Many species live in the oceans, in ecosystems including coral reefs and seagrass beds near the coasts, and in the open water. The global scientific community is working hard to determine the number of species in the oceans, but the task is difficult. Currently, the Ocean Biodiversity Information System reports a little more than 147,000 species. However, because it is estimated that more than 80% of the oceans remain unobserved, the number of species living in the ocean is expected to be much larger than what we know so far, maybe millions of species.

In addition to being home for many thousands of creatures, the sea is like a battery that constantly receives, absorbs, and releases energy. The sun is the main source of energy for the oceans, both directly, through light and heat energy, and indirectly, by heating the air to produce winds. The oceans also receive energy from the pull exerted on the Earth by the moon, planets, and the sun. These forces mean that the water of the ocean is in constant motion: waves rise and fall, tides come and go, and currents flow around the globe. These movements are very important for Planet Earth: they provide food and oxygen for the plants and animals of the seas and they also help mold the coastline through erosion and accretion, which is the buildup of sand. What if all this unending ocean movement could be used to produce a source of electricity, too? This is more than just a scientist's dream-keep reading to learn more!

The Formation of Waves, Ocean Currents, and Tides

Waves are produced by winds blowing across the surface of the sea. The time between each wave varies from 4 to 30 s. Waves occur both far out at sea and close to the coasts. When the wind blows hard, as occurs during a storm, the waves become higher. Tsunamis are a different type of wave. They are produced by earthquakes, volcanic eruptions, and the impact of meteorites landing in the sea. For example, when the earth shakes during an earthquake, the water moves, and then gigantic tsunami waves form in the open sea and travel toward the coasts. In this article, we will be focusing on the types of waves that normally occur, not tsunamis.

Ocean currents are mainly formed by the rotation of the Earth, variations in the seabed, and the differences in the temperature and salinity (saltiness) of the waters in the sea. Some ocean currents are very strong and the major currents even have specific names. Some currents carry warm, or even hot water; others carry cold water. These currents affect the weather. For example, the Gulf Current starts in the warm waters of the Gulf of Mexico and travels to northern Europe, giving the places it passes warmer temperatures. Near the coast, we can find powerful, shorter currents due to the shape of the seabed. These currents keep the water oxygenated and transport nutrients away from the coast.

Tides are produced mainly by the magnetic attraction of the moon and the sun on earth's oceans. As the moon and the sun move, the water in the oceans is drawn toward or away from the coasts, producing a rise and a fall in the level of the sea. Depending on the coastline, high and low tides can occur once or twice a lunar day, 24 h 50 min, which is the time it takes the moon to go around the earth. The tidal changes in sea level are very small in some places, while in others they are extremely noticeable. For example, some islands, such as Mont Saint Michel in northern France, are joined to the mainland at low tide by a road that crosses the sands. But at high tide, the road is covered by deep water and the people on the island are cut off for about 9 h.

Producing Electricity From Waves, Currents, and Tides

The unending movement of waves, currents and tides can be used to produce clean, renewable electricity for our homes, schools, and industries []. To harvest the energy from the ocean, special devices are used. To capture the energy, certain parts of these devices move as the water moves, and the movement generates electricity that is then transported to the coast. Buoys and turbines are two examples of devices that can be used to capture the energy from the ocean's movement.

are structures that float on the sea and move up and down with the motion of the waves. These buoys are attached to various mechanisms such as a cylinder that moves a driving a generator that can convert the movement into electricity. The buoys can be attached to long columns called , which are anchored to the seabed ( Figure 1), or the entire device can be free-floating in the ocean (Video 1). These devices can be placed in the deep waters of the open sea, or closer to the coast.

Figure 1 - An example of how electricity can be generated using wave movement.

The floating buoy is attached to a spar, which is a long column attached to the seabed containing electricity-generating machinery. Electricity is produced as the waves move the buoy up and down the spar, which moves a piston that drives a generator. Then the electricity is sent to the coast through an underwater cable.

Video 1 - Producing electricity from ocean waves.

can also be used to harness the energy of ocean currents ( Figure 2, Video 2). Turbines have blades, kind of like propellers, that can be turned by the force of the ocean currents. The spinning turbine is attached to an electricity-generating device, and as the turbine spins like a propeller, a series of gears increase the rotation of the rotor allowing the turbine generator to produce electricity. Ocean currents are almost constant in direction, speed, and flow, and they carry large amounts of energy. Turbines can also be used to harvest the energy from currents that are produced by tides. Sometimes a type of dam called a is constructed to store water at high tide; at low tide, the gates of the barrage are opened, and the stored water flows out fast enough to move a series of turbines.

Figure 2 - Energy can be generated from ocean currents and tides using turbines.

The blades of the turbine are turned by the currents, and the energy is captured by an electricity-generating device which is attached to the blades.

Video 2 - Producing electricity from ocean currents and tides.

Once electricity has been produced by these devices, it can be transported to the coast through an underwater cable or stored in special batteries.

Ocean Energies: Challenges and Opportunities

While these devices may seem quite simple, inventing machines that will work in all weather conditions, sometimes in deep water, it is a real challenge for scientists. The costs involved in designing, installing, and maintaining these technologies can be extremely high. The ocean environment is often harsh and dangerous, and conditions can be unpredictable, meaning strong structures are required to withstand the aggressive nature of the ocean. Support and funding are still needed for further research, to test prototypes, and to develop full-scale devices that can provide a stable supply of clean, renewable electricity.

Additionally, precautions must be taken to avoid undesirable effects on the environment. For example, these devices may alter ocean currents, causing food and larvae to stop following their natural patterns. Also, if the turbines produce noise, it can disorientate marine animals, causing them to collide with devices or nearby land. Early research has shown that fish and marine mammals can avoid hitting the devices; but sometimes they do not. It is important for scientists continue to research how local plants and animals respond to these devices. As new information is collected, we will know how to build and install these devices so that energy production does not have a negative effect on the plants and animals of the ocean.

Despite these challenges, there is great potential for generating electricity using techniques that harvest the movement of the oceans. In theory, the energy of ocean movements could supply the world's energy demand many times over! Energy harvested from the movement of the oceans is renewable, meaning it will not run out like fossils fuels eventually will. Another big advantage is that creating electricity from ocean energy does not generate CO ₂, and therefore does not contribute to global warming and climate change. Continued research into these electricity-generating technologies is worth the effort because climate change is a growing problem. It is critical that we reduce the emission of CO ₂ into the atmosphere, to protect the future of the earth and all its creatures! So, the next time you are at the ocean, in addition to having fun and enjoying the fantastic beauty of the sea's natural features, remember that someday the ocean might even help us to obtain the electricity we use in our everyday lives! There are endless possibilities!

Glossary

Conflict of Interest

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Acknowledgments

We appreciate the help of Jill Taylor in proof-editing the text for style and grammar. We also thank Valeria Chávez for developing the concept for the videos, Edgar Muñoz for his work on the graphics of the figures and videos, as well as Miriam Silva for lending her voice to the production of the videos.

Footnote

References

[1] ↑ Uihlein, A., and Magagna, D. 2016. Wave and tidal current energy-a review of the current state of research beyond technology. Renew. Sustain. Energy Rev. 58:1070-81. doi: 10.1016/j.rser.2015.12.284

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How Can We Use Ocean Energy to Generate Electricity?

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The oceans represent almost 70% of the surface of our planet, and they are in constant movement through waves, tides, and currents. These movements are formed differently: waves develop because of the action of the wind; tides because of the moon and the sun, and currents because of differences in water temperature and the rotation of the planet.

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Young people aged 8 to 18 from all over the world took part in do your :bit 2021. They came up with amazing, innovative solutions that worked towards the Global Goals and solved problems facing the world.

Our judges chose winners from six global regions - Africa, Asia & Pacific, Europe, Latin America, Middle East and North America - in the three challenge categories. Find out about the winners, runners up and their entries below.

To see more from the winning projects, including entry videos and additional photos, read the news articles from September 2021 here

8-14 year olds, micro:bit solutions
Young people were challenged to design and make a solution using the micro:bit in this category.
Africa
Nigeria
Marvelous created and coded an amazing tech solution to help prevent kidnapping. Marvelous was concerned with previous incidents in Africa and designed, built and tested a device that could help. The device uses a transmitter and receiver to send distress signals and alert parents to danger.

Asia and Pacific
Taiwan
Cheng-En, Ko-Hsin and Zi Qing realised that rapid climate change was contributing to rising water levels, putting birds who previously relied on the river for their habitats in danger. Using the micro:bit, the 'Best birds guardian' senses rising water and pulls the birds' nest to safety on the river shore.
China
Jingyu Xiao liked seeing plant walls in his city but wanted to protect them from the frequent typhoons that hit. He created a smart living wall that could automatically retract and extend according to the weather forecast. He also added a soil moisture sensor to ensure the plant wall was appropriately watered.

Europe
Italy
Theo, Harry, and Timofei wanted to create an efficient and affordable solar panel to make reusable energy more appealing. Using the micro:bits light sensors and servos, their solar panel moves to always face the sun, improving productivity and efficiency.

Latin America
Costa Rica
Arieh and Samuel built a prototype to work towards achieving Global Goal 13: Climate Action. Together they created a 3D printed solar-powered electric boat. They created 2 prototypes and tested them on the water before choosing the most effective elements of each one for their final design.

Middle East
Iraq
Mustafa and Mand created the ' Angry Tree', a device that monitors trees and alerts humans to issues such as dry soil, high heat, and attempted tree felling. They recognised the importance of trees in the battle against climate change and created a complex solution to the problem of tree destruction.

North America
USA
Clara built the innovative 'Hermes' shoe that charges your phone as you walk. The shoe encourages people to exercise and increase their step count by charging their phone at the same time - improving mental health and generating renewable energy!
USA
Kenna and Margot created a portable filtration device, dedicated to achieving Global Goal 6: clean water and sanitation. In their creation, a micro:bit controls UV LEDs that work to sterilize drinking water. The device is also solar-powered - making it affordable and portable.

8-14 year olds, paper prototypes
In this category, we asked young people to create a paper prototype to explain their idea.
Africa
Nigeria
Rajunor, Theophania and Jinelle thought up a solution to alert people to environmental changes that could cause asthma attacks. The team discovered that asthma patients suffered more in cloudy seasons and so came up with the idea that uses a temperature sensor and alert system to solve the problem.

Asia and Pacific
Australia
Indiana wanted to help her family members who struggled with severe anxiety. She created 'Total Relax: Massage box', a wearable solution that measures your heart rate and reminds you to relax.

Europe
United Kingdom
Brodie, Charley and Zoey created a paper prototype for 'The Healthy micro:bit'. This device reminds you to go outside for some fresh air and vitamin D every 90 mins. The solution records how long you have been outside and suggests activities you could take part in.

Latin America
Uruguay
Emily, Melanie and Valentina created a huge model to illustrate how their idea, a safe environment for bees, would work. The device measures temperature and humidity and counts the number of bees visiting.

Middle East
Lebanon
Jana drew plans for a reusable, virtual facemask. Our do your :bit judges were impressed with the amazing creativity and innovative thinking Jana brought to her entry to solve the very real problem of disposable mask waste.

North America
USA
Zong was inspired by the tentacles on an octopus to create his paper prototype for a soft drain cleaner. A micro:bit would control four motors that can delicately move around intricate spaces. The device was designed for cleaning drains but Zong thought it could also be used for medical surgery.

15-18 year olds, micro:bit solution
15-18 year olds were challenged to design and make a solution using the micro:bit.
Africa
Tunisia
Ghassen created an innovative solution that uses braille to allow visually impaired people to share text messages. The do your :bit judges were impressed with the well-constructed prototype and solution for people who would not be able to participate in an activity that many of us take for granted.

Asia and Pacific
Malaysia
Ahmad, Mifzal and Muhammad invented an 'Oxygen Percentage Analyser' to detect deforestation in a more efficient way than using satellite images. The creation uses two micro:bits - one placed in the forest, and one with the forest ranger who will be able to constantly monitor the oxygen levels of the forest.

Europe
Ireland
Aoife and Emma built a micro:bit creation to encourage physical activity and limit screentime. 'Exercise is the key', which makes use of the micro:bit accelerometer rewards physical activity with 15 minutes of screentime. The girls identified that using the micro:bit allowed them to make their creation small, and therefore more practical for the user.

Latin America
Uruguay
Sebastian wanted to create something to help people stay healthy and hydrated. The 'Smart water bottle' uses micro:bits for two functions - one to measure the intensity of the sunlight and remind you to shelter and stay hydrated, the other checks the water level in your bottle and reminds you to take a sip.

Middle East
Lebanon
Mahmoud and Yasmina worked together to create 'G.A.N.T - Gas and Noise Trapper '. The device protects people from noise and air pollution. G.A.N.T uses sound and gas sensors attached to the micro:bit to measure smoke and noise levels. If it detects dangerous levels the micro:bit triggers a servo to shut the window.
Lebanon
Ali devised a large-scale automatic tree farm that uses a network of micro:bits to control and maintain the trees' growth. He envisaged that the farm could be used to grow trees to replace those lost in bushfires.

North America
Canada
Alicia and Esmée created 'Micro:Calm', an all-in-one micro:bit device that provides users with multiple coping mechanisms to deal with anxiety. This included a fidget toy, emotion check-in, box breathing and a game. The girls hoped this could be used by people of any age and work towards achieving Global Goal 3 - Good health and well-being.

Runners up

8-14 years old, paper prototype category

Africa

Martha, Gift & Mary, Nigeria - a mosquito alert system that releases insecticide to protect its user.

Daniella & Victoria, Kenya - social distancing sensor to monitor crowds during the pandemic.

Asia and Pacific

Wan Ahmad Faris, Malaysia - a cooking oil container that measures the amount of oil used.

Sameen, Lowriance & Niva, Australia -a car made of eucalyptus leaves to protect koalas from bushfires.

Europe

Sophie, Verity & Lilly, UK - the 'Shell Cam', a camouflaged wildlife tracker to monitor endangered species.

Lily, UK -'Moody Bear', a bear that provides positive messages to help people feeling lonely.

Middle East

Mustafa, Fatma & Deniz, Turkey - a solar-powered highway lighting system.

Dalal, Haya & Noura, Lebanon -'The Para Feel' helping paralysed people to express their feelings.

North America

MiLeigh, USA - the'Courage create' feelings selector to support people with their mental health.

Noah & Alexander, USA - a package carrier drone to help reduce the amount of delivery trucks on the roads.

8-14 years old, micro:bit solution category

Africa

Oumayma, Tunisia - a facemask that moves to cover your mouth when you sneeze.

Mariem, Tunisia - the'Safe:bit cap' to prevent you from falling asleep when whilst driving.

Asia and Pacific

Wu Tao, China - the 'Smart Care Butler', a device that supports elderly people living alone.

Europe

Andrej & Nina, Slovakia - a device that recycles bottles in return for sweets.

Adit, UK - a smart village that alerts its residents to natural disasters and saves energy by automatically turning lights off.

Latin America

Hannah, Costa Rica -'Water to the Rescue', a water saving device that monitors how long you're using water for in many household activities.

Rafael, Antonio & Vinicius, Brazil - a people counter controller to avoid overcrowding in public spaces during the pandemic.

Middle East

Ali & Mohammed, Bahrain - the 'Thermo hat' that monitors temperature and warns users to have a break and drink water when it gets too hot

Amr, Saudi Arabia - the micro:bit greenhouse that can take care of plants and fish

North America

Aidan, USA - an in-car eC02 measurer that keeps drivers aware of the c02 emissions

15-18 years old, micro:bit solution

Africa

Farah, Tunisia - a micro:bit necklace that monitors and discourages shouting.

Peace & Gracemary, Nigeria - a micro:bit device to detect blocked pipes and reduce flooding.

Asia and Pacific

Chi Kei & Ho Tung, China - an intelligent parcel cabinet that disinfects its contents.

Yuxi & Yiyun, China - a smart walking stick to help people with visual impairments.

Europe

Marius, Lithuania - an automatic bottle and can sorting recycling bin.

Emanuele & Barnabas, Hungary - a micro:bit counter to measure meals intended for refugee camps.

Latin America

Miguel & Valentina, Colombia - a micro:bit water purification system using affordable and easy-to-find resources.

Felix, Peru - a programmable lighting slalom course to encourage exercise.

North America

Victoria, USA -'The Meat Machine' which weights how much meat you are consuming.

Julia, USA - a micro:bit device that to monitors the type and amount of fish caught.

Special Mention
Okorafor, Gladsome and Chibuike, Nigeria
The do your :bit judges wanted to give a special mention to this team in Nigeria for creating a device that they could easily see being used in real life. Okorafor, Gladsome and Chibuike created the 'Headcount micro:bit' to help reduce overcrowding.

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Young people aged 8 to 18 from all over the world took part in do your :bit 2021. They came up with amazing, innovative solutions that worked towards the Global Goals and solved problems facing the world.

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1000s of children across the world took part in do your :bit 2019/20. Find out more about the winners and runners up from each region.

Africa

Success, Chris-Jacob and Sharon from Nigeria found out that under water pipeline vandalism was causing harm to sea-life around their country's coast line. They knew they could use the micro:bit to create an alarm system but they didn't have any micro:bits at their school. They designed their winning solution using the micro:bit simulator on the MakeCode editor and the judges loved their creativity.

Asia & Pacific

Anqi from China designed a device that prevents birds from colliding with glass windows. She used a micro:mate board and an ultrasonic distance sensor alongside the micro:bit and some LEDs to create a truly unique solution.

Europe

Danylo, Oleksandra, Volodymyr designed a 3D printed cleaner-boat to help clean a polluted river near where they live in Ukraine. The team worked hard to create a prototype in their robotics class at school and updated the boat after it was tested to make it more efficient.

Middle East

Zayd created the Z Palm Tree - an innovative solution towards Global Goal 15, Life on Land, which enables a tree to 'communicate' its needs. Zayd used multiple external and internal sensors to create the Z Palm Tree, including a vibration sensor and a flame sensor. The tree even shows emotion via two LED matrices that create a face that moves its mouth when talking.

North America

Lynn created a complex device as a solution towards Global Goal 15, Life on Land. Lynn's creation aims to not only solve the issue of deforestation but also raise awareness of it. Lynn used a gator:microphone, a camera and a Raspberry Pi to detect loud sounds in forests. The invention takes a photo when it detects a sound and posts it to a Twitter account for a park ranger to review.

Latin America

Mauro and Jan decided to design a solution after discovering that hammerhead sharks are in danger in the waters of Isla de Cocos off Costa Rica where they live. The solution uses the radio function of the micro:bit to connect a collection of buoys and boats in the area the sharks inhabit. The micro:bit on the buoys can also alert the police station if boats do not change direction when advised to by their onboard micro:bit.

Runners Up

AFRICA: Happyness, Steven and Janeth, Tanzania - 'Providing lights in rural areas'. This team project was designed to ensure that people in Tanzania can access electric lights in the evenings.

ASIA AND PACIFIC: Sze Kay Chan, Sharol and Jayven, Malaysia - 'Project Aquagreen'. This complex automated aquaponics system automates the routine tasks required to operate an aquaponics system.

EUROPE: Plamena, Bulgaria - 'Save the Brown Bear'. Plamena designed a safety collar that used the micro:bit radio function to protect brown bears that live in Bulgaria.

MIDDLE EAST: Hussain, Saudi Arabia - 'Trash Watcher'. This creation measured the mass of waste in bins and sent a message to the recycling team to collect them when full.

NORTH AMERICA: Arushi, Canada - 'MY SCALE' is an affordable and portable water quality measuring device which used simple accessories found in a pencil case.

LATIN AMERICA: Florencia, Thiago and Morena, Uruguay - 'Mini Automated Greenhouse'. This team project helps protect existing forests and support the cultivation of more trees to repopulate forests that have been destroyed.

Special Mention

The judges also gave a special mention to Raul and Zach from America for their creation - The Sea Turtle Gender Cooling system! Raul and Zach wanted to prevent Sea turtles from becoming extinct by ensuring that there are enough male turtles in the world to mate. They read that if a turtle egg incubates above 30C the turtle hatchling will be female but if it goes under 27C, they will be male. Raul and Zach created a system that can cool or heat the turtle nest to determine the turtles' gender.

Raul & Zach's prototype sketch.

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1000s of children across the world took part in do your :bit 2019/20. Find out more about the winners and runners up from each region. Success, Chris-Jacob and Sharon from Nigeria found out that under water pipeline vandalism was causing harm to sea-life around their country's coast line.

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Children across the world took up the micro:bit challenge in 2018/19. Find out more about the winners from each region.

Africa

Joseph was introduced to the micro:bit by his ICT teacher and designed a health monitor for school children to wear for his winning challenge entry. His monitor used the micro:bit to quickly detect illness in children so they could get prompt treatment and avoid missing too much school! His success was celebrated at the Teens Can Code event in Nigeria.

Asia & Pacific

Team Food Waste Watchers from Singapore designed a monitor to solve the problem of food waste at their school. They created a device which used the micro:bit, a sensor and a screen to weigh the amount of food being thrown into a bin. The school implemented the Food Waste Watcher device and it helped reduce food wastage in the school canteen. They even got to present their device to Lee Hsien Loong, the Prime Minister of Singapore.

Europe

Team Veliki in Croatia created the spine:bit to prevent bad posture and help fix slouching after their friends' dad was suffering with a bad back. Their invention used the micro:bit accelerometer and LEDs in a wearable accessory.

Middle East

Zayd created Dr Robot to help children who suffer from asthma, especially in places like Saudi Arabia where frequent dust-storms can cause attacks. The robot included multiple micro:bits, a dust sensor, touch sensor, distance sensor, servos and motors. It notifies parents of their child's health and prompts children to take their medicine on time!

North America

Elizabeth created an affordable home security system after one of her friends' houses was nearly robbed. The alarm, made with the micro:bit and a strip of LEDs, flashed red, white, and blue to emulate police lights. Since taking part in the challenge, Elizabeth thinks she would like to work for Apple or Google in the future!

Latin America

Kathellen, from Brazil, designed a solution to help keep her local river clean after she noticed lots of rubbish being dumped in it. She created Buoy:bit using the micro:bit, an LED light and a foam buoy. Buoy:bit uses the micro:bit's accelerometer to detect when rubbish is thrown in the water and and plays an alert to let people know.

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Children across the world took up the micro:bit challenge in 2018/19. Find out more about the winners from each region. Joseph was introduced to the micro:bit by his ICT teacher and designed a health monitor for school children to wear for his winning challenge entry.