It's a truism among renewable energy wonks that in order to run our society on renewable energy, we'll need a revolution in energy storage technology.
The reason? Solar and wind are intermittent power sources. The sun goes down and the wind stops blowing, but we don't ever stop using electricity. That means, so the thinking goes, that either we need to get most of our power from something other than solar and wind, or we need to store electrical power generated on bright windy days for use on calm nights. Problem is, storing enough power to supply an energy demand the size of California's would be mind-bogglingly expensive.
But an expert who just might be the world's foremost renewable energy wonk says the truism is wrong, and that society can be kept fully powered entirely on renewables, using minimal storage. There will be no technological revolutions required; just a bit of choreography.
Amory Lovins, who's been a widely respected renewable energy expert since the 1970s, offers a persuasive argument that we need not worry about the intermittent nature of wind and solar power. The grid can handle it, he says, using current technology to forecast both power production and demand, shifting from one solar plant or wind turbine to another as wind and sunshine vary from region to region.
Instead of relying on expensive base-load power plants to generate most of our supply, which usually means natural-gas-fired plants in California, that carefully choreographed use of energy from renewable sources over a wide region can supply almost all of the power an industrial society needs.
In a video posted to YouTube last week by Lovins' energy think-tank, the Rocky Mountain Institute, Lovins uses Texas' grid as an example. Choreographed solar and wind could produce 86 percent of Texas' power handily, says Lovins, assuming a few common sense conservation measures. The remaining 14 percent comes from reliable sources of renewable energy that we can turn on and off for power when we want them. These "dispatchable" sources of renewable energy include geothermal, biomass, and biogas.
Lovins says storage has a role to play in this vision of a choreographed grid, but not by way of massive high-tech battery banks. Instead, he envisions tapping the power stored in electric cars plugged into smart chargers, and using a type of thermal energy storage in which air conditioning units create ice when power is abundant, then use that ice to cool buildings during periods of peak demand.
Here's the video, peppered with real-world examples of successfully choreographed renewable energy grids:
"A breakthrough in cheap bulk storage of electricity would be helpful, but not vital," says Lovins. "We needn't wait for it, and the market isn't waiting."