On November 2, 2004, Colorado residents approved Amendment 37, a ballot initiative creating a Renewable Portfolio Standard (RPS). Under the new standard, utilities with over 40,000 customers must provide an increasing percentage of electricity from renewables, reaching 10 percent by 2015. The Colorado RPS defines renewables as including all solar, wind, geothermal, and biomass, and small hydroelectricity systems (of 10 megawatts or less). Currently, renewable energy supplies 2% of Colorado’s electricity demand. The amendment also established net-metering standards and mandated rebates for customer photovoltaic systems. It also capped residential rate increases due to investments in renewables at 50 cents per month. Colorado is the only state to approve a Renewable Portfolio Standard through a ballot initiative. Proponents of the measure cited energy supply diversity and rural job creation as the major impetus for the legislation. Colorado is the 17th U.S. state to adopt an RPS.

See a Map of States with Renewable Portfolio Standards [1]
Read the Colorado Ballot Initiative [2]