OK, having spent an absurd amount of time bashing on a crappy article that came out while I was on vacation, let me turn my attention to an extraordinarily good one (via HillHeat): "A Solar Grand Plan," by Ken Zweibel (NREL), James Mason (Solar Energy Campaign), and Vasilis Fthenakis (Brookhaven National Photovoltaic Environmental, Health and Safety Research Center).
Some flaw in my character leaves me much less able to analyze things I like, so mostly I’ll just urge you to go read it. Here are the nut concepts, though, via the Scientific American editors:
• A massive switch from coal, oil, natural gas and nuclear power plants to solar power plants could supply 69 percent of the U.S.’s electricity and 35 percent of its total energy by 2050.
• A vast area of photovoltaic cells would have to be erected in the Southwest. Excess daytime energy would be stored as compressed air in underground caverns to be tapped during nighttime hours.
• Large solar concentrator power plants would be built as well.
• A new direct-current power transmission backbone would deliver solar electricity across the country.
• But $420 billion in subsidies from 2011 to 2050 would be required to fund the infrastructure and make it cost-competitive.
In some ways, the authors’ estimates are conservative. They do not account for any technological advances or economies of scale beyond 2020 (when the public funding stops and the industry becomes self-sufficient). They also do not account for growth in other renewable sources like wind, geothermal, and biomass. With more optimistic assumptions along these lines taken into account, it’s likely that renewables could cover 100% of electricity by 2050.
The authors do throw one hail mary though: the notion that compressed-air and molten-salt storage can be scaled up to massive, widespread industrial application in relatively linear fashion.
That’s right, it’s our old nemesis, energy storage.
They dismiss batteries with a single sentence:
Most energy storage systems such as batteries are expensive or inefficient.
That seems quite hasty to me. I’m guessing batteries are going to see huge, game-changing advances in the next few years. Batteries and capacitors are still where I’d put my long-term money.
But the authors think compressed air and molten salt are with us now and could be deployed immediately. (For more on recent developments in molten salt storage, see the Energy Blog.)
What do our energy storage experts think?