Developers haven't built a new power plant of any significance in Maryland for over a decade — one reason the state imports more electricity than almost any other in the country, racking up extra charges for consumers.

But change is coming.

Two large projects, permits in hand, could begin construction this year. Two more seek approval. Land-clearing work is underway on a fifth, a small facility intended to run when demand is high.

Industry veterans say it's hard to guess at the impact on rate-paying customers, given how much is in flux. Coal-fired units at two other plants in Maryland are earmarked for retirement in 2018. Expected closures of out-of-state coal plants could ripple locally, too. And the proposed new plants might not all get built.

If the Baltimore-Washington corridor comes out with a net gain in electrical generation, though, that could push down energy costs and two recurring charges that customers pay to keep the lights on.

"The result of competition … should be falling prices," said Kimberly Frank, an attorney at the law firm Kaye Scholer who represents state utility commissions in federal proceedings. "That's the only reason we deregulated markets in the first place."

Angst over a lack of competition — and dissatisfaction with the regional system to incentivize it — prompted Maryland regulators two years ago to, in effect, order up a new power plant. That sparked a pitched battle between the state and owners of existing power plants that's still working its way through the courts.

But the heart of the matter is a debate about whether the system for getting new power plants is good for consumers. Supporters say it allows the market to work. Critics say the primary beneficiaries have been the owners of existing plants, such as Chicago-based Exelon Corp., parent of Baltimore Gas and Electric Co.

Maryland officials are among those unhappy with the setup. The state imported 42 percent of its electricity in 2010, the fifth-largest share in the country, according to the most recent analysis by the Maryland Public Service Commission.

Abigail Ross Hopper, director of the Maryland Energy Administration, said the state wants "as much local generation as possible" — from both conventional power plants and other sources, such as solar panels and wind turbines.

"Having energy close by that doesn't have to travel so far along the energy highway makes sense," she said.

The state's concern is partly about reliability, partly about cost. Electricity rates in Maryland are the 13th highest in the country, according to the U.S. Energy Information Administration.

Electricity is often cheaper to the south and west, where plants are plentiful and population less so. It can be imported — but for large swaths of Maryland, that comes with a catch. Massive importing clogs transmission lines, adding costs.

Under the system run by multistate grid manager PJM Interconnection, the BGE territory paid about $90 million in "congestion" charges each of the last two years, according to the Public Service Commission.

Separately, BGE customers in recent years have collectively forked over hundreds of millions of dollars in "capacity" charges — essentially a reservation fee. The money flows to power plant owners in exchange for being available to churn out electricity. The payment has generally been higher than average here due to the constraints.

Capacity payments cost the average BGE residential customer about $190 last year, compared with roughly $77 across PJM overall. That's according to an analysis by the American Public Power Association, a critic of the system.

These charges are part of the reason that BGE and Pepco customers who buy electricity from their utility are paying over 20 percent more for that supply this summer than customers of Potomac Edison in Western Maryland, beyond the point of transmission congestion.

'Really big detriment'

Ryan Barbera is president of Columbia-based Unleashed Technologies and Intelishift Technologies in Ashburn, Va. The cost of electricity is always on his mind — data centers gobble kilowatts. He contends that urban Maryland would have more of the facilities if not for higher electricity expenses.

"The No. 1 issue is the cost of power," he said. "It becomes a really big detriment."