A grand solar plan for the United States


in Economics, Politics, Science, The environment

Sign in Sophie’s Cosmic Cafe

The latest issue of Scientific American features an article about a ‘grand solar plan.’ The idea is to install massive solar arrays in the American southwest, then use high voltage direct current transmission lines to transfer the energy to populated areas. The intention is to build 3,000 gigawatts of generating capacity by 2050 – a quantity that would require 30,000 square miles of photovoltaic arrays. This would cost about $400 billion and produce 69% of all American electricity and 35% of all energy used in transport (including electric cars and plug-in hybrids). The plan depends upon storing pressurized air in caverns to balance electricity supply and demand. The authors anticipate that full implementation of the plan would cut American greenhouse gas emissions to 62% below 2005 levels by 2050, even assuming a 1% annual increase in total energy usage.

The authors stress that the plan requires only modest and incremental improvements in solar technology. For instance, the efficiency of solar cells must be increased from the present level of about 10% to 14%. The pressurized cavern approach must also be tested and developed, and a very extensive new system of long-distance transmission lines would need to be built. While the infrastructure requirements are daunting, the total cost anticipated by the authors seems manageable. As they stress, it would cost less per year than existing agricultural subsidy programs.

Depending on solar exclusively is probably not socially or economically optimal. The authors implicitly acknowledge this when they advocate combining the solar system with wind, biomass, and geothermal sources in order to generate 100% of American electricity needs and 90% of total energy needs by 2100. Whether this particular grand plan is technically, economically, and politically viable or not, such publications do play a useful role in establishing the parameters of the debate. Given the ongoing American election – and the potential for the next administration to strike out boldly along a new course – such ideas are especially worthy of examination and debate. It is well worth reading the entire article.

{ 6 comments… read them below or add one }

Milan January 4, 2008 at 11:38 am
Nonymous January 6, 2008 at 8:31 pm

$400 billion? That’s not so bad. They are thinking of spending $40 billion on systems to protect commercial jets from shoulder-mounted heat seeking missiles.

Working to limit a major reason why the Middle East is such a volatile region sounds like a better use of money.

. January 9, 2008 at 11:01 am

A solar grand plan
A roadmap to getting 70 percent of U.S. electricity from solar by 2050

Posted by David Roberts at 5:58 PM on 08 Jan 2008

Read more about: energy | solar voltaic power | renewable energy
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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).

. January 9, 2008 at 11:02 am

“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.”

. February 18, 2008 at 10:34 am

Eliminating fossil fuels is friggin’ cheap

By Gar Lipow

Scientific American’s grand plan to provide a bit over a third of U.S. energy from solar sources provides insight into what it would cost to phase out all or most U.S. greenhouse emissions. Bottom line: a lot less than current military spending.

The total cost of the SciAm plan: $420 billion over the course of that 40 years, or slightly over ten billion dollars per year — less than current fossil fuel subsidies, less than the new subsidies “clean coal” would require.

The authors suggest phasing out fossil-fuel powered electricity over the course of forty years, using a solar dominated electricity grid. They suggest Compressed Air Electricity Storage (CAES) and thermal storage to compensate for the intermittent nature of solar electricity, and High Voltage Direct Current (HVDC) transmission lines to move solar electricity from where it is generated to where it is needed.

. February 25, 2008 at 10:38 am

Running the U.S. on Solar Power

Peak U.S. demand, according to the EIA, is almost 800,000 megawatts. Actual available capacity is 900,000 megawatts. So let’s make our solar capacity equal to today’s total installed electrical generating capacity.

Assuming the entire 1,900 acres is needed for the plant (maybe not a good assumption, but all I have), then this breaks down to (280 megawatts)/(1,900 acres), or 0.147 megawatts per acre. This of course includes all of the land associated with support functions, and it may include area for future expansions. So the calculation may be conservative.

My calculator indicates that 6.1 million acres is an area of 9,531 square miles, which is equivalent to a square of just under 100 miles by 100 miles (which would be 10,000 square miles). That’s a large area, to be sure. But the possibility is there. A lot of “land” is available right now of rooftops.

A couple of caveats. First, this calculation does not make a provision for a mass migration to electric transport. That would clearly require (a lot) more power. On the other hand, we already have a lot of installed electrical capacity in the form of hydroelectric (78,000 megawatts), other renewables (24,000 megawatts), and nuclear power (100,000 megawatts). This lessens the power requirement from solar.

Other conclusions from the previous essay remain the same. There are around 100 million houses in the U.S., so there is quite a bit of surface area readily available, right where the power is needed. Your results will obviously vary depending on whether you live in Maine or Nevada. The cost is still a staggering $6 trillion. However, to put that number in perspective, at $100/bbl, the U.S. would spend $6 trillion on oil in less than 8 years.

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