Colorado has perhaps the most ambitious RPS law in the nation. Signed into law in March 2010 by former Governor Bill Ritter, HB 1001 mandates state utilities obtain 30 percent of their power from renewable sources by 2020. Over the last six years Colorado has tripled its RPS mandate. In a 2004 referendum, Colorado voters approved a 10 percent by 2015 RPS, and in 2007 that requirement was increased to 15 percent by 2020.
Wind, solar, geothermal and biomass qualify as renewable sources under the law.
Under the latest update, utilities must supply 12 percent of retail electric sales from renewable sources from 2011-2014, 20 percent from 2015-2019, and 30 percent by 2020.
The 2010 law also requires investor owned utilities to purchase 3 percent of their residential sales from distributed generation e.g., residential solar panels by 2020.
Source: HB 10-1001