How green are alternative energy sources?

By using a technique known as life cycle assessment, a pair of Greek researchers look at the total environmental impact of alternative energy technologies as compared to the impact of an equivalent energy output through burning fossil fuels.

• Wind and geothermal energy are indeed green alternatives. The efficiency of these systems — over their entire life cycle — is comparable to that of fossil fuels.
• Solar power did not fare as well. The electricity produced by photovoltaic cells is less efficient when production, running, and recycling is taken into account.

However, solar energy has the benefit of economy of scale; if you produce enough solar cells and have them covering a large enough area, the total life cycle efficiency for the generated electricity tips in the favor of solar cells when compared to traditional fossil fuels. Also, the authors noted that the pollution of solar systems is far, far less then traditional fossil fuels, even though they represent a lower thermodynamic efficiency.

The authors state, “A significant advantage of the use of renewable energy systems is that they are environmentally friendly because overall they result in lower dangerous pollutant emissions, this and one other major factor, they are essentially inexhaustible.”

Source: Int. J. of Global Energy Issues, 2007. DOI: 10.1504/IJGEI.2007.014865

Go to original by Matt Ford, ArsTechnica

This entry was posted on August 16, 2007 at 6:31 am and is filed under Science & Technology. You can follow any responses to this entry through the RSS 2.0 feed.