Alternative energy issues

Pie in the sky will remain so. We need more nuclear. [Link]

As oil prices recede from all-time dollar highs and some of the hot air gets let out of energy policy debates, it’s a good time to remember that here’s a key concept missing from almost every popular discussion of the subject: energy density. Specialist economists get it, but almost nobody else does. It is important to understanding why most forms of “alternative energy” are mirages, and what a sane energy policy would actually look like.

The background to this is that the few technologies we have for storing electricity (batteries, pump-fed ponds above hydroelectric turbines) are lossy and don’t scale well. Worse, power transmission is significantly lossy as well. These mean several things, all of them bad.

Absence of a decent storage technology means we can’t really time-shift electricity demand. When more electricity is needed (for example, to run air conditioning during the day in the American Southwest) more power plants have to be running and feeding power to the grid in real time. There’s no way to run plants at night and store the generated power for daytime use.

Transmission losses mean our ability to space-shift demand is limited, too, though not as severely. Electricity-intensive industries (the classic example is aluminum smelting) need their own dedicated power plants nearby.