Duquesne Light, which distributes electricity to Pittsburgh, is asking federal regulators for permission to quit PJM Interconnection, the grid for Pennsylvania, Maryland and a dozen other, mostly Mid-Atlantic states. The reason: High costs the PJM has built into its pricing system that are helping cause big bills Duquesne customers, Baltimore Gas & Electric customers and many others. Being on the border between PJM and MISO -- the Midwestern grid -- allows Duquesne to seek another partner. Duquesne objects to PJM's "capacity pricing" that pays incumbent generators for guaranteeing electricitiy for the grid at times of peak demand, spokesman Joseph Vallerian told me. MISO doesn't have capacity charges.

While increasing grid reliability, capacity pricing also produces an incredible and outrageous windfall for the generation companies. They already have a tight hold on the PJM market; capacity pricing makes it even tighter. Unfortunately, Maryland utilities can't quit PJM; most are many miles from the next-nearest grid network. And BGE would never quit anyway; its parent, Constellation Energy, is reaping big windfalls from capacity pricing. Here's what I wrote earlier this year about capacity charges:

The rigging of the electricity marketplace to enrich power companies and executives looks even worse than we thought.

Just as Maryland was getting shocked by higher kilowatt prices, grid managers have allowed extra profit for generation outfits such as Constellation Energy, parent of Baltimore Gas and Electric Co. The bonus, whose magnitude was revealed Friday, might eventually cost the typical BGE household $10 a month or more and add hundreds of millions of dollars to Constellation earnings.

Apparently, it wasn't enough that, after deregulation seven years ago, Constellation took over the BGE generation plants with no compensation to BGE customers. It wasn't enough that Constellation charged customers an additional $528 million in "stranded costs" by arguing that the valuable generators might be obsolete.

It wasn't enough that, after last year's expiration of deregulation-required price caps, the plants' cheap coal and nuclear fuel costs give Constellation supercharged profits in a market inflated by more-expensive natural gas generation.

Now grid managers will let generation companies such as Constellation levy a surcharge that Baltimore energy experts South River Consulting calculate could eventually cost BGE households about $200 a year. BGE says it's less -- maybe $120 a year. Either way it's too much.

The capacity charge is a humdinger, destined for a Ripley's museum. It does not pay for coal, uranium, salaries or any other expense. It's basically a fee that BGE, Mittal Steel and other users pay to ensure access to potential megawatts at times of high use.

But as a practical matter it is pure profit for generation outfits, especially those with plants in areas such as Central Maryland, where demand exceeds supply. Based on auction prices announced Friday, the capacity charge could eventually net $200 million a year just for Constellation's Brandon Shores and Calvert Cliffs plants, says South River.