Unbridled Energy: Predicting Volatile Wind, Sun

Utilities Ramp Up Focus on Forecasting When Renewable Fuel Is at a Peak to Avoid Squandering Power That Still Can't Be Stored

By JEFFREY BALL
WSJ

For more than a century, producing power has been a matter of flipping a switch. Need more electricity? Fire up some fuel. Need less? Dial the flame back down.

Things won't be that easy in a world that gets much of its energy from renewable sources, which come and go at nature's whim. Wind tends to blow hardest at night -- a problem, since people use electricity mostly during the day. Sunshine can lose its intensity in seconds if eclipsed by a cloud -- inconvenient for people who like their air conditioners to run steadily on summer days.

To harness renewable energy more reliably, some companies are experimenting with ways to story energy when the output is high and then distribute it when output is low. WSJ's Jeff Ball reports on the efforts to build a better battery.

Many states and countries are pledging to produce 20% or more of their electricity from renewable sources within about a decade. That will be a major stretch. The recession has severely crimped renewable-energy investment. Proposals to turn over large swaths of desert and coastline to renewable-energy generation are encountering angry opposition. And the drop in fossil-fuel prices has removed much of the public appetite for a big renewable-energy bid. Yet those very pressures are pushing renewable-energy proponents to pursue their goal as efficiently as possible. And so the search for ways to accommodate the vicissitudes of wind and sun continues to shape up as one of today's great technological quests.

A convenient solution would be to overcome wind and sun's intermittence by storing the energy and then dispensing it later, on windless or overcast days. But storage technology is still embryonic.

(More here.)