This article examines environmental impacts through Life Cycle Assessments (LCA). A Life Cycle Assessment is an overall environmental examination of all the steps that eventually make up a technology. This study focuses on biophysical impacts that are quantifiable and excludes social impacts. Since all technologies are different, some LCA's require an examination of social impacts if it is relevant as is the case with hydropower. However, social impacts are discussed in other articles.
The LCA's of hydropower and windpower have the best outlook. Hydropower is excellent because it provides added benefits which include:
- The multiple uses of reservoirs that provide flood control, irrigation, and drinking water.
- Unique operating flexibility that can increase the reliability of electricity supply. In addition, nuclear energy is also an attractive option. Natural gas is not perfect, although it is better than oil. Coal performs the worst among environmental criteria.