Photovoltaic (PV) power is created from a burst of coal-sourced energy priced at 4 cents/kWh, which you get back as an intermittent and declining dribble over the following 20 years at 15 cents/kWh.  The numbers vary with location, but the basic relationship remains the same – at best, the energy produced by PV panels is at least four times the cost of the power consumed in making them.

That is one thing.  The main thing is that over their lifetimes, PV panels now produce slightly more energy than what it took to make them. 

So a civilization that relies upon PV power is just getting its energy back, but at four times the cost.  If PV power were used only to make PV panels, and even assuming no energy losses in the process, then PV power at 15 cents/kWh would produce panels that made power at 60 cents per kWh, and so on to infinity.  So there is nothing renewable about PV power.

There are some applications in PV power is very useful, such as pumping irrigation water, in which the requirement is too small to justify a diesel pump or the cost of extending grid power to the site.  In fact, PV power is well under the cost of power from diesel – you just can’t access it at a time of your choosing.  It also has a role where high-priced grid power and reticulation costs make it competitive.  But it can’t pretend to be renewable or sustainable.  Apart from those niche applications, it bleeds energy and treasure from our civilisation. 

The economics of wind power might be a net positive, but a wind-powered economy would have a standard of living similar to that of 17^th-century Holland.  One rule of thumb is that each megawatt of wind power used in the grid requires half a megawatt of gas turbine backup.  That is why some of the major oil companies have been so much in favor of renewable energy.  It tricks us into burning a higher-cost fossil fuel. 

Making cheap energy from a process requires that the energy produced from that process be at least five times the amount of energy that went into making it.  Anything less than that, and civilization will go backward very rapidly.  Instead of mandating renewable energy and installing PV panels, we should be concentrating on developing the technology that will sustain civilization in the post-fossil fuel eternity.

In that regard, we have a choice: either plutonium breeder reactors or thorium breeder reactors.  We should make the choice and get on with it. 

David Archibald, a Visiting Fellow at the Institute of World Politics in Washington, D.C., is the author of Twilight of Abundance: Why Life in the 21^st Century Will Be Nasty, Brutish, and Short (Regnery, 2014).