A new solar array built for a Baltimore County retirement community is among the metro area's largest, the installation firm said Tuesday.

ABM Industries installed the 1.2 megawatt array on land owned by the Glen Meadows Retirement Community in Glen Arm. Washington Gas Energy Systems owns the 4,150-panel solar system and will sell the power it produces to Glen Meadows.

Solar power accounts for a small percentage of Maryland electricity generation, but the number of arrays in the state are expanding quickly. Commercial-scale projects such as the Glen Meadows array have grown from less than 1.5 megawatts in total five years ago to more than 60 megawatts now, according to the Maryland Energy Administration.