Among alternative sources of energy, harnessing the ocean tides is still in the early stages of development, but major progress was announced recently when Marine Current Turbines Ltd. (MCT), Bristol, United Kingdom, completed the installation of the world's first megawatt-scale tidal turbine at Strangford Narrows off the shore of Northern Ireland. The 1,000-ton SeaGen tidal turbine, capable of producing 1.2 MW, was scheduled for 12 weeks of testing before being commissioned to feed power into Northern Ireland's electric grid.

When fully operational, the tidal system's 52-foot diameter twin rotors will operate for up to 18 to 20 hours per day to produce enough clean, green electricity, equivalent to that used by a 1000 homes. This is four times greater than any other tidal stream project so far completed, including MCT's earlier 300kW Seaflow system installed off Lynmouth in Devon in 2003.

Tidal power has several advantages over wind, notes the website Ecogeek, www.ecogeek.com. “The power generation is more predictable (since you always know when the tide will turn) and it is believed that they will have less ecological impacts since roads do not need to be built to them. There hasn't been enough data yet to determine what affects they will have on marine life.”