A Maryland lawmaker wants the state's utility regulator to look at whether Pepco is inflating the cost of lighting the streets at night, raising the cost for taxpayers.

Del. Al Carr, D-Montgomery County, is asking the Maryland Public Service Commission to give extra scrutiny to a residential electricity rate increase requested by Pepco, claiming the utility might be jacking up streetlight costs.

In a March 14 letter to PSC Chairman Kevin Hughes, Carr wrote that Home Depot charged the same price for 70-watt, 100-watt and 150-watt high-pressure sodium light bulbs -- the kind used in streetlights.

However, Pepco charges different rates for the bulbs and their maintenance, "despite the fact that bulb, photocell and labor costs do not differ based on wattage," he wrote.

Pepco charges $341 for maintenance over the five-year life of a 70-watt bulb, $370 for a 100-watt bulb and $380 for a 150-watt bulb. That does not include the cost of the electricity used to power the bulbs. It does include cleaning glass domes, replacing burnt-out bulbs and sensors and repairing knocked-down poles.

A Pepco spokesman said the utility had not seen the letter. Nobody from Pepco was able to respond to requests for comment about the letter's claims.

A spokeswoman for the PSC said she was unable to comment on the letter's claims, as they were related to an open case before the PSC.

According to Pepco billing statements, Montgomery County has a higher share of the cheaper 70-watt bulbs -- almost three times more than the other two combined. Prince George's County has a higher share of the more powerful, more expensive bulbs, meaning that county's taxpayers pay more for the bulbs and their maintenance.

Carr also claimed Pepco charged almost five times more for light maintenance than what local governments that contract maintenance out through a competitive bid process pay.

Lighting Maintenance Inc. -- Montgomery County's contractor -- charges $75 per bulb over a five-year period, regardless of wattage. However, Lighting Maintenance's fee doesn't cover replacing knocked-down poles.

Carr goes on to question why Pepco only gives municipalities a partial rebate if they contract out their own maintenance, making counties like Montgomery still pay what he calls a "phantom" maintenance charge.

Finally, Carr asks the PSC to look at whether it was appropriate for Pepco to give away $43,000 in street lighting, electricity and maintenance to a Montgomery County municipality over three years.

Minutes from a Feb. 20 Chevy Chase View meeting show Pepco installed 34 150-watt lamps valued at a total of $33,000 for free in 2010 and didn't charge the municipality for $10,000 worth of power provided over the next three years.