Glossary

Low entropy energy

High-quality energy or energy that is concentrated and "available." For example, electricity is considered to the energy carrier with the lowest entropy (i.e. highest quality) as it can be transformed into mechanical energy at efficiency rates well above 90 percent. In contrast, fossil fuel's chemical energy can only be converted into mechanical energy at a typical efficiency rate of 25 % (cars) to 50 percent (modern power plants). The chemical energy of biomass is of lower quality.