Distortions of cheap energy.

I recommend this short paper (the first 8 pages of a multi-item newsletter) on renewable energy. Two takeaways:

The concept of energy return on energy invested (EROEI) is new to me, but intuitive. The more energy you get from any amount of energy invested, the better. The EROEI of wind and solar are about 3.5:1, while natural gas is around 30:1 and nuclear is 100:1.
The cost of renewable energy is largely driven by the cost of energy needed to produce solar panels and wind turbines, so the past decade's sharp decline in renewable energy costs may have been driven less by the learning curve - as is commonly believed - than by historically low prices for energy along with an unusually low cost of capital. If so, increases in energy prices in general could cause renewable energy prices to climb back above their competitive point (as might be expected for something that has such a low EROEI).