Marine Energy Projects Pick Up Momentum
Hopes of harnessing the churn and flow of the seas to generate power are pushing forward work in the small but growing tidal and wave energy industry. Despite a tough investment climate, proponents expect the technologies to begin contributing significant amounts of clean energy to power grids around the world within a decade.
Tidal energy technology harvests power from the rise and fall of the sea caused by the gravitational forces of the Moon and the Sun and the rotation of the Earth. Wave power systems harness the energy of surface waves.
The immense force of the tides has long tantalized those hoping to harvest energy from them, but although a few small projects are operational, the technical barriers are high. Two distinct technologies exist — traditional dam-based plants and more recent “tidal stream” generators, built like underwater windmills. But tidal dams can be ecologically harmful while in places suitable for tidal stream plants, currents can sometimes be so strong that they risk destroying the generating turbines.
Capturing energy from waves may be even trickier. But proponents say that if wave projects are successful, the energy available for harvest would be even greater than with tidal stream power, which requires particular physical conditions, like a narrows where water runs quickly. While not as predictable as the tides, waves can be anticipated several days in advance as they move across the sea, and they tend to be strong in winter, when demand for electricity is high.