Renewable Portfolio Standards

Energy use from non-renewable energy sources, such as coal and petroleum, are significant contributors of GHG emissions. A Renewable Portfolio Standard ("RPS") is an important and effective tool that can be implemented to reduce emissions from a state's energy sector. An RPS requires that a minimum amount of renewable energy is included in the mix of the electricity sources servicing a state. Many states have an RPS, while some are more aggressive than others the establishment of an RPS is a cost effective and reliable method of reducing a state's greenhouse gas emissions. Common renewable energy sources include wind, solar, geothermal, biomass and hydropower.

According to the Union of Concerned Scientists total new renewable energy production from state RPS programs will reduce as much carbon dioxide as taking 5.4 million cars off the road or planting over 1.6 billion trees. In California, approximately 11 percent, or roughly 30 billion kilowatt hours, of the state’s total electricity production (as of April 2004) comes from renewable resources, according to a report by the California Public Utilities Commission.

The following gives a summary of states with an RPS. Percentages refer to a portion of electricity sales and megawatts (MW) to absolute capacity requirements. Most of these standards phase in over years, and the date refers to when the full requirement takes effect.