Constellation Energy Group Inc., owner of Baltimore’s utility, bought a minority stake in closely held Astrum Solar Inc. to offer solar installation services to its 1 million retail power customers.

Back in March, Shelley Cohen and Mike Gala sent out a request to contractors to submit proposals on their project: to have solar panels installed on the roof of their colonial home in the District.

Kim and Mark Reichelt spent years weighing the cost of a solar panel installation at their Wayland home against the energy savings and reduced carbon footprint they’d achieve by harnessing power from ...

Astrum Solar officials said the average solar electric system in Cumberland County right now is about 5 kilowatts, which has an initial price tag of about $30,000. With a 30 percent federal tax credit ...