Last month, we predicted that one of the country's big vertically integrated solar companies would make a move into the energy storage business this year by acquiring a U.S.-based storage company. Here's the first. 

On Thursday, solar (and wind) giant SunEdison announced it was acquiring the project development team, four existing projects, and roughly 100 megawatts of project pipeline of Solar Grid Storage. The Philadelphia, Pa.-based startup specializes in packaging lithium-ion batteries and inverters with commercial solar PV projects -- and paying their way by providing lucrative frequency regulation services in the market run by mid-Atlantic grid operator PJM.

But under its new ownership, Solar Grid Storage will look to provide a much broader variety of storage-based services in support of solar and wind power, CEO Tom Leyden told us in an interview.