Green Energy Guide

A Consumer's Guide to Sustainable Electricity

November 8, 2000

Green Energy Guide: Environmental Impacts

Sustainability implies long-term social, economic, and ecological health and vitality. How can we make sense out of all these disparate yet interrelated issues? The price paid per kWh of electricity poorly reflects the true cost of a particular electricity source and obscures the unique profile of advantages and drawbacks for each electricity source. Moreover, weighing the impacts of, say, coal combustion on human health vs. the impacts of a large hydroelectric dam on the health of a river ecosystem is like comparing apples and oranges. A truly sustainable electricity source must be renewable, reliable and economical, with minimal impacts that would affect the well-being of present or future generations of people or ecosystems. More specifically, a source must meet the criteria listed below.

To see how the different sources stack up on each issue, click on the name of the issue.

To see how the different sources stack up overall, click on The Bottom Line.

To look at detailed tables of quantitative data comparing the sources, click on Appendix.


  • Must be renewable over the long term

Land: Impacts on Terrestrial Habitat

  • Land required for electricity production must be small
  • Degree of impact and risks to terrestrial habitat must be low
  • Areas of high value for food production, wildlife habitat or aesthetic value must not be required

Water: Impacts on Aquatic Habitat

  • Amount of water required for electricity production must be small
  • Degree of water pollution and damage to aquatic habitat must be low
  • Must not endanger drinking water supplies.

Air and Climate: Atmospheric Pollution Impacts and Greenhouse Gas Emissions

  • Amount of air pollutants generated over entire lifecycle must be small
  • Emissions of air pollutants most dangerous to human health must be particularly low
  • Emissions of greenhouse gases must be low

Human Health and Safety

  • Occupational risks must be low
  • Risks to public during general operation and in case on an accident must be low
  • Risks to the health and well-being of future generations must be low

Energy Return on Investment

  • Return-on-investment ratio must be high
  • Ratio must reflect the entire lifecycle
  • If likely to change, the ratio must be more likely to increase than decrease in the future


  • Price must be low enough to be economically feasible
  • Price must not be out of line with the true costs to society
  • Price should be more likely to drop in the future than rise