This map depicts the status of the Renewable Portfolio Standard (RPS) by state. There are 13 states that have enacted a requirement where a certain percentage of the energy provided by the utilities in those states must be derived from renewable resources, like wind, solar, landfill gas-to-energy, biomass, or geothermal. Standards, percentages, and types of technology vary from state to state, but generally there is a phase-in period, so that utilities can ramp up over a period of several years. Three states have structured their RPS more as a goal than as an enforceable regulation. Several other state legislatures are considering enacting an RPS.