U.S. Sen. Ben Cardin and Rep. John Delaney, both Maryland Democrats, unveiled a congressional resolution Thursday that would set a national goal of having 50 percent of the nation’s electrical power from carbon-free sources by 2030.

Cardin said that reducing pollution from coal-fired power plants west of Maryland would help clean up the Chesapeake Bay. He pointed out that warmer Bay waters -- likely from rising carbon dioxide levels in the atmosphere -- already threaten aquatic vegetation that provides vital habitat for blue crabs.

At a Capitol Hill briefing, the two Maryland lawmakers said that while only 30 senators and 103 House members — all Democrats — have signed on to the goal-setting resolution, they hoped to get enough Republican support to pass it. Delaney noted that as many as three dozen House Republicans support investments in clean energy.

Getting half of the nation’s power from wind, solar and other renewable sources won’t be easy. They accounted for just 10 percent of total U.S. energy consumption and 13 percent of electricity generation in 2014, according to the U.S. Energy Information Administration.

However, Cardin explained that the resolution’s 50 percent “clean energy” goal includes nuclear power and hydropower, which together account for another 30 percent of the nation’s electrical power.

An EIA analysis of the impact of the Clean Power Plan estimates that by 2030, 43 percent of the energy production would come from nuclear power plants and other non-carbon sources, Delaney spokesman Will McDonald said Friday. The sources’ contributions would be 18 percent from nuclear generation, 12 percent from wind power, seven percent from  hydropower, three percent from solar sources and 3 percent from other renewables, McDonald said.