Fickle weather can make for inconsistent power supply from wind and solar. Weak winds will render a turbine useless -- strong winds can damage it. Cloudy days and, well, night-time, interrupt solar generation. But, the tides keep rolling in... and out. Unless we lose the Moon or the Earth stops rotating, we can depend on the tide.
So, the folks at Snohomish PUD in Washington State have started to investigate this power source in the Puget Sound -- one of about 40 sites in the world that has proper conditions to make tidal generation worth the effort. They are studying five tidal energy sites in the Puget Sound, which, if developed, could produce enough energy for up to 70,000 homes.
Is reliability a substitute for power? The Ocean Energy Council estimates that the world's tides could generate 6,400 megawatts of power (assuming a 10% capacity factor). Wind power, even with its on-again and off-again flow, is already producing more than 5 times that amount of power in the US.
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