Thursday, September 11, 2008

A Lotta Green throws out some staggerling large numbers in its editorial about the true impact of California's quest for generating as much as 25% renewable power.

To hit Prop 7's goal of 50% renewable by 2025, approximately 500 gigawatt hours of renewable power will be required daily. To put that in perspective, 500 gigawatt hours of wind power requires an investment of $300 billion; solar would cost even more (but costs are likely to come down over time). And this doesn't even touch the cost of storage infrastructure:

"In California the demand peak is around 50 gigawatts, and the off-peak minimum can get as low as 20 gigawatts. The time of peak demand is between 5 p.m. and 10 p.m., when appliances are operating along with flat screen TVs and PCs. During this period, when the sun is down and the wind yields aren’t yet at maximum output, at least 25% of California’s daily electricity draw is consumed, about 250 gigawatt-hours. It is reasonable to assume most of the renewable energy used to fulfill this demand will have to come from stored wind, and stored solar. So what would it cost to store 100 gigawatt-hours of energy?

Yesterday we had the opportunity to speak briefly with David MacMillan, CEO of Megawatt Storage Farms, Inc., a company that is developing large scale electricity storage using NAS (sodium-sulphur) batteries. He claims that “not including site acquisition and preparation,” storage technology using NAS batteries would come to about $350,000 per megawatt-hour. This means the cost to load balance California’s grid, should 50% of her energy come from solar or wind sources, would probably run about $35 billion dollars. This figure doesn’t include transmission upgrades, nor does it include site acquisition and preparation..."

To quote former Sen. Everett Dirksen, " A billion here, a billion there-- pretty soon it adds up to real money."

Megawatt Storage Farms []