In comparison, biofuels and other alternative energy sources remain minor players in the overall economy. (discovermagazine.com)
I previously wrote on regulatory obstacles to wind power and other alternative energy sources here. (volokh.com)
Economical, large - scale energy storage would also even out variability in certain other alternative energy sources such as wind power (for which tractor - trailer - size sodium sulfur batteries are currently being tested). (gm-volt.com)