Two days ago it was Optimal Technologies with $25 million toward software for electrical grids; today, it’s SmartSynch with $20 million for wirelessly communicating meters. I haven’t gone back and done an official count, but with well over half a dozen large fundings in the past few months, the efficiency-focused smart grid space looks to have emerged as the hot cleantech venture space du jour.

“Smart grid” is a catch-all term for a number of technologies that aim at measuring and controlling the process of sending electricity from generation plants to homes and businesses. The former area is SmartSynch’s specialty. The company’s meters are capable of hooking up to networks via any of several wireless standards like WiFi, CDMA or ZigBee to divulge the data they collect.

Fundings may be flooding in right now, but SmartSynch is no newbie. Founded in 2000, the company has taken $80 million to date. It has also deployed about 125,000 meters, and grew 125 percent last year. Meters have turned out to be a particularly bright area to innovate in, because they’re advantageous to several constituencies.

The advantage comes in giving more information to both customers and utilities. Instead of seeing electricity usage as one big block on a bill received once a month, customers can see usage on an almost moment-to-moment basis. Following the old adage “knowledge is power”, that information gives both parties the ability to plan out usage based on when electricity is most available, saving utilities power and both sides money.

SmartSynch’s chief technology officer, Henry Jones, says his firm’s communication technology, which is installed in meters made by Elster, General Electric and Itron, has brought in about $15 billion in additional revenues for utilities so far. That’s good news for the company, because it’s the utilities that buy and install the meters. Their customers include some rather large ones, including Socal Edison, Florida Power & Light, and Canada’s Hydro One.

Other firms, including Silver Spring Networks, have fairly similar technology and strategies. However, Jones claims that’s not a problem: Each firm has its own approach to communicating data, he says, and each approach is useful for different applications, leaving a wide market chunk for each competitor.

But that’s not much use to any new startups who might want to muscle in on the action. After all, several of these firms have years of lead time. So what are the next big opportunities? Jones thinks the next step is getting meters to report not just back to the utility, but also directly into the home or business they’re installed in; he says SmartSynch is preparing to release several meters that do just that.

Hooking into the gas and water meters is also a good opportunity, along with integrating the data from all three major utility streams. On a more granular level, there’s space for companies that measure and control electricity usage by specific devices, like air conditioners and lighting. And of course, there’s opportunity to be had not just in communication and control, but in helping to decipher all the information that’s being generated.

For the present moment, the wave of smart grid startups shows no sign of slackening. Several more announcements that I’m aware of are on their way in coming weeks, and a few in front usually means a pack behind.

The $25 million SmartSynch received was the Jackson, Miss., company’s fourth funding. Credit Suisse, a new investor, led the round, along with another newcomer, Southern Farm Bureau Life Insurance (perhaps they’ll tack “venture partners” onto that name at some point). A heap of previous investors also came along for the ride: Batelle Ventures, Beacon Group, Endeavor Capital Management, GulfSouth Capital, Battelle’s affiliate Innovation Valley Partners, Kinetic Ventures, OPG Ventures and Siemens Venture Capital.