In another sign that wind-driven energy is here to stay on a substantial basis, Exelon Corp., a rival of BGE owner Constellation Energy, is expanding its wind-power business. It's buying Deere & Co.'s renewable-energy division for $900 million. (OK, it's not quite a billion dollars. But I couldn't fit $900 million in the headline.)

The deal gives Exelon, a big nuclear operator, like Constellation, 735 megawatts of wind-generation capacity. That's about the capacity of a good-sized nuclear-power reactor. The deal also includes projects in development of twice that amount. Exelon has been marketing wind energy as a wholesaler, including in West Virginia and Pennsylvania, reports the Associated Press.

Constellation, for its part, is now behind Exelon in wind. CEG is getting ready to launch its Criterion wind project in western Maryland. It's 70 megawatts and is projected to cost $140 million.