WAVE POWER
By: Joe LampsterWATER may cover 70 per cent of the Earth's surface, but so far it has made precious little contribution to human energy needs. The wind and the sun, not to mention the heat in rocks far underground, are being harnessed as the world races to reduce its reliance on polluting fossil fuels. Now it’s the turn of the sea.
While wind and solar power have struggled to compete with the economics of burning coal and gas, or damming a river for hydro generation, wave and tidal schemes have long been considered hopelessly uneconomic. The world still waits for the first commercial-scale wave or tidal plant to function successfully.
However, several companies now believe they have cracked the problem in using the vast energy that is generated by the movement of the seas and oceans.
The British are about to create the world's first large-scale energy farm off the coast of Cornwall. Wave and tidal energy concepts are the most advanced of all the various ways that engineers believe they can harness the power of the oceans. Tidal requires large tidal flows, and there are limited places at which those occur; in the US, for example, tidal energy is feasible only in Maine and Alaska according to the California Energy Commission.
Coming up in the rear is ocean thermal energy conversion, but this is viable usually only in the tropics. It is estimated by the US National Renewal Energy Laboratory that the world's oceans absorb solar radiation equivalent to about 250 billion barrels of oil in energy terms. Ocean thermal energy conversion, or OTEC, uses different temperatures at various depths -- so long as the temperatures between the warm surface and the cold deep water varies by at least 20C -- to drive a power-producing cycle. But the economics are against the technology at this stage, according to the laboratory, and research into OTEC has been suspended. There have also been thoughts of producing electricity using the deep ocean currents, ocean winds and salinity gradients -- but so far these remain little more than pipe dreams.
28 March 2008
3 comments
3 comments so far
Tom Williamson
2008-05-07 03:43:25The government, individual, companies should support more on renewable energy. Instead of companies processing oil and making plastic they can build windmills. In fact, with the rapid growth in the wind industry, which is the leading owner and operator of renewable energy projects in the US, are having trouble finding trained technicians to assemble windmills. With this growing demand, it opens up an entirely new job market with new financial opportunities.
Bill Dalton
2008-04-21 08:36:20What didn't get much publicity was a new $72 million fund set up in the Australian State of Victoria to breathe new life into large-scale renewable energy projects across the state, such as solar energy, wave power, geothermal and biomass conversion. The money will come from The Clinton Climate Initiative was run by former US president Bill Clinton's William J. Clinton Foundation. Victoria will use the foundation's purchasing consortium to deliver items such as hybrid buses, use new financing models to accelerate the transition to low energy street lighting and procure alternative waste treatment technologies. The irony is that Victoria is heavily reliant on brown coal and much of the State’s human energy and money is going into the folly of make coal clean. There’s no evidence at all the turning coal into gas and synthetic diesel, while capturing the carbon underground in natural gas wells would provide a carbon-neutral solution. It’s technologically as feasible as flying to Pluto.
Jim Bannister
2008-03-31 02:52:35Kenichi Horie is a brilliant man! It might seem obvious to think that a boat powered by the most abundant energy source in the ocean: the waves. But the 69 year old sailor will attempt to travel between Hawaii and Japan (4,350 miles) this month in his Mermaid II, the world’s most advanced wave-powered boat. And if he makes it, he will get the Guinness world record for the longest distance traveled this way. And one more thing: it will be the most ecological boat since sail ships. Even though it won’t set any speed world record with a top speed of five knots, being 2-3 times slower than diesel boats, Horie wants to prove that wave power can work in real life. The Suntory Mermaid II uses a pair of movable fins mounted under the bow to generate forward propulsion using dolphin like kicks. Solar power is used to power the onboard equipment. And to prove that Horie actually cares about the environment, he made his boat out of recycled aluminum. Best of luck sailor!