The Maryland Public Service Commission last week approved the merger between Exelon and PEPCO — a move many environmental groups, as well as the Maryland attorney general, have vigorously opposed.

The commission, whose approval is required, voted 3-to-2 to allow Chicago-based Exelon to merge with PEPCO, the utility responsible for supplying power to Washington, D.C., its suburbs and a large part of the Delmarva Peninsula and New Jersey.

According to the commission’s press release, Exelon must comply with 46 conditions. Among them:

• Higher reliability standards, as PEPCO has generated many complaints about service outages and long wait times to restore power

• $43.2 million for energy-efficiency programs in the DC suburban counties so that customers can have more renewable choices

• A $100 rate credit for Delmarva Power and Pepco residential customers, so they will realize some of the savings from the merger

• $14.4 million in Green Sustainability Funds for Prince George’s and Montgomery counties

• $4 million for sustainable workforce programs, as an acknowledgement that the merger could result in involuntary layoffs

• Construction of 20 megawatts of renewable energy generation to be split between the Eastern Shore and the suburban DC area.

The commission reached the decision after 17 days of hearings. Even with the concessions, environmentalists and Maryland Attorney General Brian Frosh had opposed it.

Chesapeake Climate Action Network said in a statement that the commission “deeply harmed the interests of ratepayers and the environment” by approving the merger. Mike Tidwell, its executive director, said the commission had “totally failed” in its responsibility to protect the interests of both, and that the conditions the commission placed on Exelon were not meaningful.

The Sierra Club called the decision “a blow to the future of clean energy in Maryland.” Earthjustice, which represented the Sierra Club and CCAN on the case, said they are worried that Exelon will use the merger to increase utility bills and that the conditions imposed will do “absolutely nothing” to offset the harm of the merger.

Frosh called the decision bad for consumers and great for monopolies. He is concerned about one company controlling the power for 80 percent of the state’s customers and said he is “exploring all options to protect the interests of Maryland customers.”

One of the worries was that Exelon, which has a lot of nuclear plants, would not be supportive of renewable energy. Exelon maintained that it would be.

The DC Public Service Commission has yet to rule on the merger.