As of the end of 2018, 29 states and the District of Columbia had renewable portfolio standards (RPS), or polices that require electricity suppliers to source a certain portion of their electricity from designated renewable resources or eligible technologies. Four states—New Mexico, Washington, Nevada, and Maryland—and the District of Columbia have updated their RPS since the start of 2019.
States with legally binding RPS collectively accounted for 63% of electricity retail sales in the United States in 2018. In addition to the 29 states with binding RPS policies, 8 states have nonbinding renewable portfolio goals.
States have used terms such as carbon-free, carbon-neutral, or clean energy to define their policies. However, each state has defined these terms in its own way to allow technologies generally not considered renewable to count toward the policy target.
New Mexico increased its overall RPS target in March 2019 to 100% of electricity sales from carbon-free generation by 2045, up from the previous target of 20% renewable generation by 2020. The new policy only applies to investor-owned utilities; cooperative electric utilities have until 2050 to reach the 100% carbon-free generation goal. The target has intermittent goals of 50% renewable generation by 2030 and 80% renewable generation by 2040.
New Mexico’s goal of carbon-free generation includes traditional renewable technologies such as solar, wind, fuel cells, most biomass technologies, and hydroelectric projects that began operation after January 1, 2007. The legislation does not specify which technologies count as carbon-free, but any technology that produces zero carbon dioxide emissions as a result of electricity production qualifies.
In April 2019, the Nevada legislature increased its RPS to 50% of sales from renewable generation by 2030, including a goal of 100% of electricity sales from clean energy by 2050. Later that month, Washington increased its RPS target to 100% of sales from carbon-neutral generation by 2050, an increase from the previous target of 15% of sales from renewable generation by 2020. In addition, the policy mandates a phaseout of coal-fired electricity generation in Washington by 2025. Nevada and Washington became the fourth and fifth states, respectively, to pass legislation for 100% clean electricity, following Hawaii, California, and New Mexico.
In May 2019, Maryland increased its overall RPS target to 50% of electricity sales from renewable generation by 2030, replacing the earlier target of 22.5% by 2024. In addition, the legislation mandates further study of the effects and the possibility of Maryland reaching 100% generation from renewables by 2040.
In January 2019, the District of Columbia increased its RPS target to 100% renewable electricity sales by 2040.