When one thinks of natural renewable power, the first things that come to mind are wind power and solar energy. These are technologies which have revolutionised the UK. Some homes now have solar panels installed on roofs to provide heating. Many new farms of wind turbines are being built both on land and at sea. Wind farms are subject to lucrative subsidies, as are solar energy farms. Many developers are attracted by the profits these can bring in. Yet recently, a 90,000 panel strong project was halted in Suffolk following intervention from the Local Government Secretary, Eric Pickles.
Maybe given the upset that such projects bring to the communities near the developments, the time has come to look at something else. And where better to look than the oceans? According to the Environment Agency, as of 2011 1.5% of Britain’s electricity comes from hydroelectric power. Most of these installations are in Scotland.
Hydroelectricity works under a similar principal to wind power. In the air case, rushing wind makes a turbine spin, which turns a generator. Hydroelectricity is identical, except that it is the flow of water through a wheel that turns the generator.
Unfortunately, with environmental concerns over hydroelectricity and exhaustion of suitable sites for installations, the UK does not plan any further hydroelectric installations. Concerns range from preventing fish and other aquatic life from migrating, to the actual process of water travelling through the dams (or other installations) causing the water to change in its composition, and hence quality.
Whilst hydroelectricity may be the more commonly imagined kind of oceanic energy (technically known as ocean mechanical energy), there is one other major kind of oceanic energy – ocean thermal energy. Just as ocean mechanical energy has a partner in wind energy, ocean thermal energy has a partner in solar – although the similarity doesn’t extend beyond the fact they both involve the sun.
Ocean thermal energy utilises the temperature difference between surface water and deeper water. Surface water is warmer as a result of heating from the sun overhead. As part of a heat exchange mechanism this warm seawater heats a volatile fluid, which then flows and rotates a turbine. The water itself never actually comes into contact with the generating mechanism. The only change it undergoes is cooling, though some models suggest it unbalances ocean nutrient levels.
The only operating setup of this kind is currently in Japan, although other projects are proposed. The main issue this technology possesses is that it is unproven – whilst it has been in development since the late 1800s, it is still to hit the mainstream. But in time, as other energy sources become exhausted (as hydroelectric power has), or politically untenable, ocean thermal energy is likely a technique that will develop further and may eventually become a mainstream energy source.