Solar power has matured as an alternative energy source over the last 20 years, but there are still obstacles to overcome before the energy from the sun can significantly supplement other sources of energy.

Collecting solar energy is only part of the process, storing it for later use is still “technically and economically challenging.”* Concentrating solar power plants, or CSPs, like the one shown here, use mirrors to focus solar radiation and generate heat that can be converted to energy, but CSPs are located where the solar radiation is most abundant year-round, which is not where most people and most of the energy demand is.

There are environmental issues, as well. Recently the California Energy Commission recommend against building a new installation in the Mohave desert because of its potential impact on turtles.

*Source: Science, 329:773, August 13, 2010, Roeb, M, and H. Muller-Steinhagen

Photo of concentrated solar power plant, and other information on solar power is available here. This structure's resemblance to Isengard is interesting...

Let the sunshine in

Why use fossil fuels when you can tap the sun’s energy directly?

Photovoltaic cells convert sunlight into electricity, and are already widely used to power small electronic devices, like calculators. Solar panels are added to roofs in certain parts of the country, for heating homes or providing hot water.

Solar energy is relatively cheap and clean, and it’s renewable as long as the sun shines, which should be for billions of years to come.

The downside to solar energy is that it is most effectively used in sunny areas, and large-scale use of solar power requires many acres of land for the solar collectors. Still, advances in solar cell research and technology forecast a (ahem) bright future for solar power.

Photo: array of solar panels, from http://is.njit.edu/competition/2009/Cat2_2_Winner_Group142/