At last - harnessing the awesome power
of the sea to stop global warming

Wavegen's 500-kilowatt Limpet turbine captures wave energy and converts it into electricity. The technology is to be installed on the Scottish island of Islay to provide electricity for the Inner Hebrides. Photo - Wavegen.

British companies are engaged in exploiting Scottish seas as a renewable source of electric power. Long-term plans range from generating electricity from the waves to harvesting power from the tides. Pulled constantly by the moon's gravity and warmed by thermal currents, the ocean's energy is created by winds whipping across its surface. The greater the distances involved, the higher and longer the waves will be.

Energy is stored in the waves until they reach the shallows and beaches, sometimes with destructive force. If only two trillion watts of electricity could be harvested from the sea, it would be the equivalent of twice the world's energy produced from nuclear, oil, gas, and coal-fuelled power stations.

One metre of a single North Sea wave front is strong enough to power 50 electric heaters. As a general rule, coastlines with an ocean "fetch" greater than 400 kilometres (250 miles), are suitable for exploitation. But even greater energy resources are available between latitudes 30 degrees and 60 degrees in the northern and southern hemispheres. Global warming and international conservation agreements to reduce "greenhouse gases" have encouraged industry to investigate how the oceans' powerful energies can be exploited economically.

The Inverness-based Wavegen is installing its 500-kilowatt (kW) Limpet turbo generator on the Scottish island of Islay to provide electricity for the residents of the Inner Hebrides islands. Consisting of a collector and oscillating water column, the Limpet uses wave power to force air up through the collection chamber, spinning the pneumatic turbine. It is driven in the same direction regardless of the air flow, sucking the air down and creating electricity as the waves subside.

The company, which has been conducting successful experiments on the island for the past 10 years in collaboration with Queen's University, Belfast (Northern Ireland), expects to begin feeding electricity to the island's grid within a year. Wavegen turbines installed in the Azores are now supplying 400 kW of electricity to the islanders. The installation was backed with European Union funding and the company is developing a machine that will float on the sea to generate electricity.

This article was abridged from Environmental Science & Engineering magazine, which also contains many more articles not posted on our Web Site. See our home page on how to order your subscription. We regret we can only accept orders from Canada and the United States.