It's shopping time in greentech.

SAP, the software giant that competes against Oracle, IBM and Microsoft for large corporate accounts, announced today that it would buy Clear Standards, a privately held firm that helps businesses track and report greenhouse gas emissions and energy consumption.

Chances are, it won't be the last. High-technology giants in the U.S., Europe and Japan have all signaled their intent to pursue opportunities in energy production or conservation. Earlier this year, for instance, Cisco announced its EnergyWise strategy, which essentially involves creating software that allows large companies control the energy consumption of data centers and ultimately building operations through Cisco networking equipment.

Intel has been selling processors to the wind turbine market and is experimenting with ways of getting its chips into smart grid equipment. Several companies such as Panasonic are trying to figure out ways to move deeper into greentech. Interestingly, Oracle just put in a bid for Sun Microsystems, which has been touting its ability to make energy-efficient servers, storage systems and data centers.

And if history is any indication, many will move into this market through acquisitions. SAP, Oracle and Cisco have bought dozens of companies over the past decade and often successfully incorporated the acquired technology into their own portfolios. (Intel has had a more checkered career in acquisitions so you will probably see that company focus more on deploying its existing products into green markets.) The recent downturn has also made potential targets far cheaper than they were a year ago. Another factor encouraging acquistions: a large number of energy start-ups now are based around familiar technologies such as networking, hardware and software. These are topics that the IT giants know a lot better than solar power.

Software companies producing energy and carbon management software could become in particular a ripe area for acquisitions. Over 40 of these companies – including Carbonetworks, AMEE, and Carbonflow – have popped up on the radar screen in the last year. Although each software package is different, most perform many of the same functions. While some have received VC funding, most have not received the kind of funding that would let them build multinational sales teams either. Privately, investors and execs at some of these companies have said that the likeliest path toward liquidity would be an acquisition.

An acquisition spree would be both good and bad for these companies. Those that get chosen would reap the rewards of a sale. Those that get left behind, however, would have to carve out survival strategies.

"Having this ability also correlates to an organization's efficiency and competitiveness. With the acquisition of Clear Standards, we will accelerate our vision to deliver a complete set of solutions to enable end-to-end sustainable businesses. We welcome the Clear Standards team to SAP," said SAP AG Co-CEO Léo Apotheker in a prepared statement.

Another market to watch would be companies that make energy management tools for software and hardware. Verdiem, which produces software for curbing energy consumption in PCs and telephones, has long been viewed by some as a potential acquisition target. It is working with Cisco on EnergyWise. Other companies in this space include SynapSense and Power Assure.

The proliferation of companies into smart grid technologies, combined with the heightened demand and sprawling nature of the customer base, will also likely lead to acquisitions.

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