How much alternative energy could the oceans of the world produce?

The Nov. 14 8.1 magnitude earthquake which struck the Kuril Islands of northern Japan generated a storm surge with enough lasting power to collapse two docks in the northern California town of Crescent City two days later.

And less than two years ago, the world was horrified at the cataclysmic destruction from the Indian Ocean tsunami created from an underwater earthquake of, geologists now estimate, some six trillion watt-hours in magnitude.

But such mind-boggling amounts of energy expenditures are all in a day’s–or a couple of hours’–work for the oceans of the world. Six trillion watt-hours of alternative energy captured from the oceans would satisfy the electrical demands of ten million U.S. homeowners for six months. Yet it only takes the oceans two hours to release an equivalent amount of energy with the crashing of its tides.

Think about it: enough alternative energy being produced in 24 hours to provide electricity to 240 million U.S. households–if there be that many–for six months.

And it’s from an alternative energy source which, unlike fossil fuels, is inexhaustible, and to which any country with a coastline has immediate access.

So what, if anything, is being done to harness this might?

So far, not much–but things are picking up.

The longest-running facility using tidal power as an alternative energy source is the Barrage du Rance, in operation since 1976 on the tidal estuary of the Rance River in Brittany. The alternative energy created there is enough to supply three percent of Brittany’s needs, at 600 million kilowatt-hours each year–or a single one-millionth of the amount of tidal energy released along the world’s coastlines every two hours.

Smaller facilities are in operation in Nova Scotia and at Kislaya Guba on the Barents Sea. And Scotland’s alternative energy policy calls for 10% of its power to be tidal-based by 2010.

Changing the fossil-fuel-based culture of the 21st century is a matter of overwhelming urgency. And, if Scotland’s decision be any example, the tide against alternative energy may be turning.