Missouri has joined the growing list of states to enact a renewable portfolio standard (RPS) mandating that a certain percentage of electricity come from approved renewable sources. Two-thirds of Missouri voters voted “yes” to Proposition C, dubbed the Clean Air Initiative, on November 4, 2008. The ballot measure specifically requires investorowned utilities by 2011 to generate or purchase electricity equaling 2 percent of retail sales, increasing gradually to 15 percent by 2021. Missouri becomes the thirtieth state to enact an RPS, while four others have voluntary utility commitments (see “Renewable Portfolio Standards — A Driving Force Behind Today’s Renewable Energy Transactions,” September 2008 edition of the Hunton & Williams Renewable Energy Quarterly). While the RPS is not as strict as in other states, Missouri may have a tougher time complying than other states. It currently generates less than 2 percent of its electricity from renewable sources, and its reliance on coal for 82 percent of its electricity is significantly higher than the national average of 49 percent.