Powering the Country with Solar: It's Not Going To Happen–But Fortunately, It Doesn't Have To

A friend asks:  By your lights, has anything changed substantively – positively or negatively – with regard to the viability and cost of CSP, molten salt energy storage, and HVDC? Are we still fully capable of satisfying the entire US electricity demand with 10,000 square miles at about $6 trillion?

The LCOE (levelized cost of energy) of PV is about $0.05, wind is $0.03 in the right places, and CSP about $0.14.  All of these are still falling, and CSP has the best chance to fall appreciably, given that the R&D in this rather immature space has the most chance of producing a breakthrough, or at least a significant improvement in cost-effectiveness/efficiency.  Now, however, given the LCOE figures above, it’s a non-starter, and thus it’s not receiving as much R&D attention as I wish it were.  However, by virtue of its connection with molten salt, it’s appropriate for islanded applications, i.e., where there is no grid to absorb off-peak power.

Yes, we need 10K square miles of whatever form of solar, given the insolation in the southwestern deserts, the efficiency, and the capacity factor, but the cost of that is way more than $6 trillion.  We’re at about 5 terawatts (power  consumption) in the U.S. right now, so even at $2/watt that’s $10 trillion, but that’s not counting the capacity factor, say 20%, so that’s $50 trillion.  That’s without storage; no one knows the cost of scaling that up; it’s huge, to put it charitably.

Fortunately, no one is suggesting that we power the whole nation with solar.  The most credible and sane approach to all this, IMO, is Amory Lovins’ 40-year plan.