I was very pleased to learn of Ken Salazar's proposal to fast-track solar energy initiatives. It's definitely a step in the right direction.
But how big a step is it, really? Let's look at the numbers.
The claim is that this could lead to Solar generation capacity able to power up to 29 million homes. (This is almost certainly hugely optimistic as it assumes all the applications actually result in completed projects.)
The average US home uses 936 kWh per month, meaning this would provide 325,728 TWh/year.
Sounds like a lot, doesn't it? Not really. According to the Energy Information Administration, in 2007 the United States used 4,156,745 TWh of electricity. Of that amount some 2,016,456 TWh was generated by burning coal.
In other words, under the most optimistic estimates, and ignoring the minor issue that the sun only shines during the day, this will produce only 8% of the electricity needed (in 2007), and could only replace 16% of what was generated by burning coal.
It's not enough. Even if you add in a huge increase in PV solar generation (and ignoring the issues this wlll create for the eletric grid), it's still not close.
So how about wind power? Salazar has previously stated that he believes wind power, in particular east coast offshore production, has the potential to replace all use of coal to generate power in this country. But according to factcheck.org, this claim is hopelessly optimistic:
We calculate that converting wind to enough electricity to replace all U.S. coal-fired plants would require building 3,540 offshore wind farms as big as the world's largest, which is off the coast of Denmark. So far the U.S. has built exactly zero offshore wind farms.
Factcheck.org continues:
Another government study last year concluded that to supply just 20 percent of U.S. electricity with wind turbines would require land-based equipment taking up an area "slightly less than the area of Rhode Island," plus scores of offshore wind farms.
Wind power definitely has a major role to play, but it's still not enough.
So what about geothermal? According to the Geothermal Energy Association, a mere 3959.7 MW of geothermal power is currently in development. This is only a fraction of the 97 TW of power we're hoping to get from solar. So it doesn't look like geothermal is going to help much.
And keep in mind that the energy needs of the United States haven't exactly leveled off. Energy consumption increased almost every year, 2.2% from 2006 to 2007 alone, and while the current recession has probably driven the numbers down, that won't last.
If you think of this in terms of Robert Socolow and Stephen Pacala's wedge model there simply aren't enough alternative energy "wedges" to reduce fossil fuel consumption sufficiently to avoid a environmental catastrophe.
This is where nuclear power and "clean" coal enter the picture. Advances in reactor design have eliminated many, but by no means not all, of the issues with nuclear power. But for better or worse, right now it doesn't look like we have a choice. Expanded use of nuclear has to be on the table.
So what about "clean" coal? As I have remarked elsewhere, I and many other people are deeply skeptical that there really is such a thing. The people promoting this need to make the case a lot better before I'll believe it is worth pursuing. But if the case can be made - I doubt it can but let's suppose - it needs to be on the table as well.
And last but definitely not least, there's conservation. This is where we all have to do better, not just by reducing our personal energy use, but by putting pressure on politicians to regulate and otherwise incent industry and agriculture to conserve.