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What factors affect the choice of energy sources by different societies?

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What factors affect the choice of energy sources by different societies?

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Environmental - the devices could disrupt the movement and migration of aquatic animals. They could also alter hydrologic and sediment systems. However, research hasn’t found any major, negative environmental effects yet.

Economic - sites with stronger currents and larger wave heights will provide the lowest cost hydrokinetic energy. The devices require maintenance, management, and monitoring. Projects also have to have available state or federal tax incentives to help finance and produce electricity.

Societal - recreational use of coastal waters could be disrupted. Fisherman, recreational boaters, and shipping transports could be effected with use of large hydrokinetic energy devices.

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What does the future use and availability look like?

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What does the future use and availability look like?

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Engineering projects are underway to hopefully one day create “wave parks” that could deliver clean, renewable energy on a commercial scale.

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What advances in technology are being pursued for use of this energy source?

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What advances in technology are being pursued for use of this energy source?

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There are two main types of hydrokinetic energy devices: wave energy converters (WEC) and rotating devices (RD).

Wave energy converters (WEC):

Oscillating water column

Point absorber

Attenuator

Overtopping Device

Rotating Devices (RD):

Tidal turbine

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What specific countries use this energy source?

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What specific countries use this energy source?

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The United States (primarily Alaska and pacific coasts) - MEDC

England - MEDC

Scotland - MEDC

Portugal - MEDC

South Korea - LEDC

Canada - MEDC

Australia - MEDC

New Zealand - MEDC

Brazil - LEDC

Chile - LEDC

Mexico - LEDC

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What are 4 disadvantages to using this source of energy?

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What are 4 disadvantages to using this source of energy?

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Glacial silt and other sediments in flowing water can move through turbine devices and erode machinery

The need for large water-space could compete with possible uses of fishing or shipping, and possibly cause damage to marine life and aquatic habitats

Some versions of hydrokinetic devices are designed to reside at the mouths of water systems, which could cause changes in hydrology and salinity that negatively impact animal and plant life

Costs of innovative technology and creating devices, researching other environmental impacts, and keeping up with regular maintenance can make hydrokinetic energy quite expensive

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What are 4 advantages to using this source of energy?

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What are 4 advantages to using this source of energy?

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A readily available hydrokinetic energy project could ensure that local communities would receive uninterrupted access to a clean, renewable energy source - as opposed to needing to send the generated energy across several miles of underwater cables.

Hydrokinetic energy projects do not contribute to greenhouse gas emissions and have very little effect on the local environment - depending on the geography of a site. These devices work to fit in with the environment rather than disrupt the environment.

The resources are renewable and do not produce greenhouse gas emissions

Tidal currents are highly predictable which allow device designs to be more efficient and precise

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How does each one of these generate energy?

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How does each one of these generate energy?

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Rotating devices (RD): harness the kinetic energy of a flow of water, such as a tidal stream, ocean current, or river, as it passes across a rotor. The rotor turns with the current, creating rotational energy that is converted into electricity by a generator. The rotating device designs are very similar to wind turbines.

Wave energy converters (WEC): transfer energy based on the fluctuating height of ocean waves. The optimal depth for wave energy power generation is between 40-100 meters; if closer to shore, the power production tends to decrease due to interactions with the sea bed.

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What parts (countries or locations) does the energy source come from?

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What parts (countries or locations) does the energy source come from?

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Alaska has some of the best potential for hydrokinetic development in both rivers and tidal basins because the state is home to 90% of the total U.S. tidal energy resource. The accumulation of both snow melt from glaciers and general, seasonal snow contribute to higher volumes of water in Alaskan waterways.

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What materials are needed to produce the actual energy?

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What materials are needed to produce the actual energy?

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Water must flow through a turbine or some other kind of device. The device requires a minimum current and water depth. Minimum current required to operate a hydrokinetic device is typically 2-4 knots. Adequate water level above the device extracts optimum energy. Hydrokinetic devices are ideally installed in locations that have relatively steady flow, rather than locations prone to serious flood events, turbulence, or extended periods of low water level.

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The energy comes from moving water