Naturally Interesting

Seen over at Gristmill:

Nevada Solar One takes up about 400 acres, mostly for mirrors and heat engines. You would have to mine about 5,300 acres to feed a coal-fired powered plant producing the same amount of electricity. Even acre for acre, I’ll take Solar One’s pleasant campus over a coal mine.

But the best is in the comments:

If you look at this from a practical point of view, one shouldn’t underestimate the problem of solar’s lack of base- and peak-load capacity.

Molten sands are certainly interesting for energy storage but haven’t been proven on a commercial scale.

So unless a viable energy storage technology becomes available, such large solar plants remain dependent on fossil fuels for their baseloads and peakloads (or biomass).

That’s why its often difficult to compare these technologies from a practical point of view.

One should look at how big a solar plant’s minimal baseload/peakload requirement is (that is, its minimal reliance on coal, gas or biomass), add this to the equation, and then compare with pure coal, which does always deliver base and peakloads.

Leaving this crucial context out of the equation, it does seem like solar-thermal plants like the one mentioned are quite efficient when it comes to the amount of space they take up. But is this really even an argument?

It seems to me that stored energy sources (coal, oil, gas, biomass) have many other advantages that make them so attractive: they can be physically moved and traded. Solar power cannot. Can’t ship concentrated solar power from one continent to another. You’re stuck in a rather inflexible local context. But then that’s probably the context many of us want to move to: one of more locally rooted energy self-reliance, instead of energy interdependence.