No one can accuse renewable energy specialist SunEdison (NASDAQOTH:SUNEQ) of being lazy. Within the span of several months last year it spun off its key assets and made a sizable acquisition.

Continuing this busy streak, SunEdison last month opened its wallet again, buying a small company called Solar Grid Storage. The market generally welcomed the move; let's see whether that reaction was justified.

Sunny days
SunEdison is in a good line of work to be in just now as renewables in general, and solar in particular, are on the rise. To cite one of several encouraging statistics, in 2014 solar energy installations grew by 30% year over year clip to 6.2 gigawatts.

But the solar market has a lot of players, including ambitious companies such as SolarCity (NASDAQ:SCTY.DL) and SunPower (NASDAQ:SPWR). Keeping up in this business is tough, and the quickest way to do that is with asset acquisitions.

SunEdison is commendably fast and opportunistic with its checkbook. Last November, the company -- in conjunction with its spinoff, yieldco TerraForm Power (NASDAQ:TERP) -- signed a deal to buy energy-from-air specialist First Wind for $2.4 billion. The acquisition closed in January.

In a stroke this made SunEdison the largest renewables concern on the planet, according to the company.

Potential energy
In early March, SunEdison announced the much smaller -- yet just as significant -- acquisition of Solar Grid Storage. Terms of the deal were not disclosed.

As its name suggests, SunEdison's new asset is in the business of providing energy storage. Extra capacity is packed into a set of batteries typically housed in a trailer-sized enclosure with other equipment needed for operation.

Energy storage has a number of uses for both residential and commercial customers. The former can stash away excess produced energy, using it later when the need arises. For businesses, storage can function much like reserve power. More importantly, enterprises can save money by automating demand reduction and "shaving" their usage during peak hours.

As a fairly new entity, Solar Grid Storage doesn't have a big footprint: At the moment, only four projects are listed on its website. SunEdison is basically buying the small entity's expertise and the potential of its storage solutions.

Selling storage
This can easily be parlayed into more business, and fast. In its announcement of the buy, SunEdison said it "now offers battery storage solutions to complement solar and wind projects worldwide." The company clearly isn't wasting any time.

If packaged well, its new asset should add good value to existing offerings; storage is a no-brainer option for any customer managing renewable assets. And sooner rather than later, it will probably be standard in the industry. After all, SunEdison's peers have crafted their own tie-ups in the segment.

SolarCity is using battery systems made by Tesla Motors (NASDAQ:TSLA) for its storage/grid management product GridLogic, while SunPower collaborates with privately held Sunverge and EnerNOC for its storage offerings.

The inclusion of storage into renewable energy providers' product mix is yet another evolutionary step in a fast-developing industry. With the Solar Grid Storage deal, SunEdison is showing it can at least keep up, if not leap further ahead.