EAI presents Cleantech Snapshots: a quick summary of some of the most interesting and innovative areas in clean technology that will drive the sustainability movement in future.
This snapshot focuses on Wave Power. Within this page you will find
- An overview of Wave power
- How it works
- Types of wave energy converters
- Basic technologies used in wave energy
- Regions with significant wave potential
- Drawbacks
Overview
- Wave power is renewable energy derived from ocean waves. It is the kinetic energy of wind interacting with water and creating waves
- Electricity from waves is generated by capturing the movement of waves to do useful work, usually turning a turbine
- Worldwide potential with existing technology is estimated to be above 2 TW, but could increase significantly with improvements in technology and accessibility
- Wave energy is the transport of energy by ocean surface waves, and the capture of that energy to do useful work – for example, electricity generation, water desalination, or the pumping of water. Machinery that can exploit wave power is generally known as a wave energy converter
- Wave energy is currently nascent, and is present only in a few regions worldwide, mostly in northern Europe. But expect it to grow in significance soon for many more regions around the world
Wave Power System (Image source)
Working
- Wave power works by placing a power generating device in the water where there are a lot of waves. As the waves pound the device, the device bobs up and down in the water
- Most of the energy comes from the rising and falling water level and requires exposure to the waves
- It refers to the harnessing of the power of water waves. Waves hold a huge amount of untapped energy, some of which we can use to power at least a portion of the world’s everyday electricity. Though estimates vary about how much power waves could contribute to the world’s energy consumption, some say it could realistically contribute about 10 percent
Types of wave energy converters
- Attenuator
- Point absorber
- Terminator
Basic technology used in wave energy
- Oscillating body: The device, either submerged or on the surface, is moved up and down or back and forth by waves. Its motion is used to drive an electric generator. Pelamis Wave Power is developing a snake-like oscillating body that would rest on top of the water, while other devices look more like buoys
- Oscillating water column: Air enters a chamber through a hole and is compressed and decompressed by wave movement. A high-powered turbine catches the air as it is decompressed
- Over topping device: A large structure, shore-based or in the ocean, that channels waves into a basin. When the basin’s water level becomes higher than the ocean’s, the basin is drained. The technology is similar to a hydropower system, in which draining water runs a turbine
Regions with significant potential for wave power generation
- Western seaboard of Europe
- Northern coast of the UK
- Pacific coastlines of North and South America, Southern Africa, Australia, and New Zealand
Drawbacks
- High initial costs
- Device breakdown
- Marine life affected
- Noise pollution