Huge Solar Power Farms

Last week's news in the New York Times about massive new solar installations in California is both good and bad news. The good: Solar power plants are at last beginning to rival conventional plants in terms of peak power production. Two new installations will combine to produce 800 megawatts of power when the sun is overhead, the amount a small to midsize nuclear power plant produces at its peak. About two years ago, Technology Review reported on plans for solar farms of unprecedented size, but those would produce only 100 megawatts or less. The new installations increase this output by almost an order of magnitude. Clearly, solar power is on its way to becoming a significant source of electricity.

The bad news: It's still not that much electricity. The very fact that 800 megawatts of solar power is big news indicates just how far we've still got to go. For one thing, 800 megawatts of solar is not equal to 800 megawatts of nuclear or coal. That's because solar works only during the day--and even then it doesn't generate peak levels in the morning and evening. Nuclear can keep cranking at near peak output day and night. The new solar installations will produce far less electricity than a comparably sized nuclear plant.

What's more, we're still talking about megawatts of electricity. To supply anticipated energy needs, we need to be thinking not just in thousands of megawatts--that is, gigawatts--but in thousands of gigawatts, or terawatts, of power. According to one report, all of the solar panels produced so far can only generate about 12 gigawatts.

This is all just to say we've got a problem of enormous scale on our hands. There are also concerns about cost--solar is still more expensive than electricity generated from fossil fuels.

But enough of the negative. The new installations are yet another sign of a rapidly expanding solar industry. This expansion will fuel itself by bringing down the cost of making solar panels. Meanwhile, technology continues to improve. That includes the development of cheaper ways to store solar power, so it can be used at night.