Behind the Numbers on Energy Return on Investment

When I proposed an article to Scientific American on energy return-on-investment, also known as EROI, I didn't realize how much legwork would be involved in gathering the numbers needed for an infographic to accompany the story.

On the surface, the measurement of EROI seems simple. It is just the energy output divided by the energy input. (For gasoline, for example, the output would be the energy in a gallon of gasoline, and the input would be all the energy required to make the gasoline—including oil exploration, drilling and refining.)

See full Article: http://www.scientificamerican.com/article.cfm?id=eroi-behind-numbers-energy-return-investment