What we now refer to as "alternative" is actually what has powered the world for millennia: the sun, and its secondary products wind, rain and biological material. Pre-industrial man farmed the sun to grow crops, cut down trees to burn, put up sails to capture wind and used mills to capture water.
Since we discovered fossil fuels, the use of these resources has decreased as a proportion of our total energy mix. We discovered much higher energy densities to be exploited by burning fossil fuels and splitting atoms.
It is this high density energy, far more than could be achieved by burning trees, which propelled us into this modern age of high energy consumption in developed states.
Why are we now returning to alternative energy sources?
Our replacements are no longer working for us. There is strong evidence to suggest that the burning of fossil fuels is affecting the climate. As we have seen in recent years, the price and availability of oil and gas are volatile, and are subject to various externalities, be they natural, economic or political.
We crave security of energy supplies as nations become ever more paranoid of losing their most ubiquitous commodity. Renewables may provide us with options.
Listed below are articles covering various aspects of these alternative energy sources. Eventually topics will include: economics, policy, law, and of course a little bit of physics here and there, because I just cannot help myself.
Alternative energy sources
Solar Energy
Wind Energy
Hydroelectric Energy
Advantages of hydroelectric energy
Disadvantages of hydroelectric energy