TWICE MARYLAND’S General Assembly has wisely refused Gov. Martin O’Malley’s plans to subsidize construction of a wind farm off the Delmarva Peninsula. Unfortunately, this year the governor may prevail.

Senate President Thomas V. “Mike” Miller Jr. (D-Calvert) says that the latest version of Mr. O’Malley’s proposal will pass the legislature. Mr. Miller should know: He stacked the committee that will consider it. The bill has 24 co-sponsors in the Senate, enough votes to pass. Mr. O’Malley (D) has eased the way by including millions in grants to boost small and minority-owned businesses that might try to involve themselves in the project.

But millions in small-business giveaways aren’t the worst element of the policy. Maryland already has a major climate plan in place, based on a requirement that at least 20 percent of the state’s electricity come from clean sources by 2020. The elegant feature of this plan is that it forces a range of renewable energy sources to compete, allowing private electricity providers to figure out the cheapest path to meeting the green mandate. It would reduce Maryland’s carbon footprint while keeping costs down for the state’s consumers.

Mr. O’Malley’s proposal would undermine that attractive feature by carving out space exclusively for offshore wind in the renewables mandate, limiting competition. He would require providers to obtain a certain amount of their electricity from wind power generated off the state’s coast, regardless of whether it’s the cheapest way to generate clean electricity for Maryland. The plan is designed to avoid sharp increases in electricity prices, but the subsidy required for the billion-dollar project would have to come from somewhere. So the proposal would add up to $1.50 a month to residential bills and increase commercial bills by up to 1.5 percent.

Backers of offshore development point out that the winds off Maryland’s coast are strong, a nearby energy resource that the state should exploit. But if the most efficient way to meet the mandate is to build offshore wind farms, then offshore wind farms will prosper under existing policy. If it’s not, then they should not be built.

If anything, Maryland should be improving its renewables mandate by removing a carve-out for solar energy that the General Assembly already established. Nuclear power and natural gas also aren’t included in the list of energy sources that can satisfy the mandate, when both could make the transition to a greener economy easier if policymakers gave them an appropriate place in the policy. If green-minded lawmakers worry that change would soften the mandate too much, they can simply raise the percentage the mandate would require from all clean sources.

These sorts of reforms are more deserving of Annapolis’s time.