In the United States many states have introduced special legislation called Renewable Portfolio Standards (RPS) – which mandates the state to promote the use of renewable sources of energy for generating electricity. Mainly these have been seen as one way to tackle the problem of climate change as well as support local solar and wind energy industries.

Maryland lawmakers approved a dramatic investment in renewable energy in the final hours of the 2019 General Assembly session, passing a measure that would require the state to generate 50% of its electricity from renewable energy by 2030 and evaluate steps to reaching 100% clean energy by 2040. In 2030, the 50% renewable portfolio standard (RPS) would include 14.5% solar and add at least 1,200 MW of offshore wind.