Not quite back to the caves

A couple days ago, I fretted that civilization is going to collapse without some spiffy technology like thorium riding in to save us like oil did a century ago. Ever since the food crisis (which is really an energy crisis) began, I've been dwelling on this more and more.

But I think it's worth remembering that under no circumstances will we go back to the Stone Age when fossil fuels run dry. Even without magical new energy sources, there exists a "backstop" technology that will allow us to continue to live a modern existence. That technology is Concentrated Solar Power, or CSP - a.k.a., focusing sunlight to heat a liquid.

As this article notes, CSP has been available as a large-scale power source since the 1800s. Cheap fossil fuels came along and made CSP economically unviable for over a century, but with those fossil fuels getting less cheap by the day, CSP is making a big comeback.

Can we run our civilization off sunlight and mirrors? Not as easily as we've been able to run it off of fossil fuels, but yes. Cars will have to run off batteries and/or capacitors, which is fine. Ships and planes will probably have to run on hydrogen electrolyzed by solar electricity, which will make shipping and flying more expensive. CSP has an EROI (energy return on investment) of 4 or 5, about half of where oil and coal are now - meaning we'll need a lot more investment to maintain a CSP-powered infrastructure than our current fossil-fuel-based infrastructure. Living standards will have to shrink or stagnate for most people, although the fact that CSP emits zero carbon might more than make up for that.

So we should be seriously planning for a CSP-based future, helping the technology to improve, and switching to electric cars. Whatever happens, it won't be the Stone Age.