Concentrated Solar Power (CSP)

The other day, I wrote a short post on Renewable Energy World extolling the virtues of concentrated solar power, and predicting that CSP would someday (probably in my grandchildren’s lifetimes) dominate the landscape of world energy production. Almost immediately, someone asked me why I held that belief, and I realized that I should have provided a bit of my reasoning. In brief, here it is:

1) The ultimate winner in energy will be safe, scalable, reliable, and inexpensive. This kills most energy technologies more or less immediately. Fossil fuels aren’t scalable, nuclear is neither safe nor inexpensive, etc.  And a great number of green energy technologies, e.g., run-of-river-hydro, don’t scale well.

2) With a few exceptions, the sun’s radiation is the ultimate source of all energy on Earth. Thus, the most obvious line of investigation for energy policy is determining the most direct way to convert the warmth of the sun into useful energy.

3) Most of the dozens of renewable technologies attempt to capitalize on this fact. The sun makes the wind blow, the rivers run, and builds the chemical bonds that are broken down when we convert complex organic molecules back into simpler ones (e.g., burning wood in our fireplaces, explode gasoline in our cars, or gasify waste in processing plants). But the most direct, efficient way to harness the sun’s energy is transferring those photons as directly as possible into electricity. This leaves us with solar photovoltaics and CSP.

4) It could be argued that PV is even more direct than CSP. And, if it weren’t for the problems in building large volumes of semiconductors for PV, I believe it would have won. But PV is ultimately doomed to significant manufacturing issues and materials shortages that, I believe, will limit scalability.

5) CSP, by contrast, uses low-cost and abundant materials, which can be deployed in areas that are relatively unimportant to plant and animal habitat (deserts). Of course, all energy-related technologies — even the dozens of breakthroughs in extracting coal, oil, and natural gas — are improving day by day. But CSP is still in its infancy. The gains in efficiency, the way in which solar thermal heat is stored to produce reliable baseload power, and the way in which that energy is effectively transmitted via high-voltage direct current to population centers — is improving every day.

I know there are people who disagree, but CSP is my pick for the late 21st Century. I only hope we still have a planet that supports life by that point.