Solar energy in its non-fossilized forms – wind, hydro, biofuels, tidal, and direct use of the sun’s rays – are called “renewable,” meaning that it does not require vast geological ages to recreate them.
The term, however, can be misleading. All can only be renewed at a pace that natural cycles allow. The amount of solar energy that shines down upon the earth may seem inexhaustible, but it is extremely dilute. In order to match the highly concentrated power of fossil fuels, it must collected over vast areas and then brought together.
It is the collection process that is not inexhaustible and not always renewable. Hydroelectric dams, the most successful form of non-fossilized solar power, back up reservoirs covering hundreds of square miles in order to generate the same amount of electricity produced by a mile-square coal plant (not counting the area required to mine the coal).…