Baltimore Gas and Electric has agreed to repay Baltimore $670,000 after it was discovered the city was overcharged on numerous utility accounts.

The mistake, which was discovered by the Department of General Services and made public this week via an audit report to the city’s spending board, was initially going to be rectified via a series of credits on city utility accounts.

There was one substantial problem with that plan. Some of the credits were so large it would have taken decades — 195 years in the case of one account — to use them.

Julia Kalloz, chief of the energy division for the Department of General Services, which manages city property, told the Board of Estimates that BGE is the sole source of data on the credits, which are associated with solar power, making it difficult to verify when overcharges happen.

The overpayments are related to special utility meters that allow customers to receive credits for solar energy generated off-site. The meters normally have zero energy usage and don’t provide energy unless the solar units at Perryman Generating Station in Harford County are unable to meet demand, city officials said.

If solar generation falls short, BGE backfills the shortfall. In that case, the company charges supply costs in addition to the cost of distribution, city officials explained.

Beginning in May 2024, BGE’s billing system for such accounts failed, Kalloz said. The company issued duplicate and erroneous bills as a result.

To sort it out, Baltimore relied on data provided by BGE to verify the bills and highlight charges issued in error. City officials said they have been meeting monthly with BGE, and by July the mistaken bills were rectified and city accounts credited, Kalloz said.

An audit presented Wednesday to the Board of Estimates found multiple accounts had been credited in excess of $10,000, sums it would take from three to 195 years to use.

Kalloz said the city instead negotiated with BGE to receive a refund to rectify the overbillings. The utility company agreed to the plan in October, and city officials said they expect the payments to be received by the end of November. Some checks have already arrived.

Nick Alexopulos, a spokesman for BGE, said it was BGE that identified the billing issue. The company “proactively kept the city informed throughout the resolution process.”

“We’ve worked closely with the city to address the matter, and the issue has now been resolved,” he said.

Comptroller Bill Henry, one of five members of the mayor-controlled board, questioned how long it took for the city and BGE to reach the agreement. Kalloz said the problem was first noted in May 2024 but credits were not issued until July 2025.

“There’s a strong desire to slam BGE for a ridiculous policy that would have put us in a position of having to wait 195 years to get our money back,” Henry said.

The comptroller noted, however, that Baltimore has a similar crediting policy if residents overpay on property taxes.

“July through November is a lot longer than I’ve ever had to work with [the Department of] Finance to get someone paid back for an overpayment,” Henry said.

Council President Zeke Cohen asked if the city had legal recourse to seek interest or penalties from BGE. Kalloz said she didn’t believe the city had legal authority to do so.

“I’m glad this is being rectified by October and not 195 years, but in the same way this utility has been pretty aggressive when it comes to their collections,” Cohen said.

“This is one where there is a little bit of fault on both sides, but I think holding them to account for accuracy is also important,” he added.