Data centers use a lot of power, and Sentilla Corp. wants to help them use it more efficiently.

The Redwood City, Calif.-based company announced Tuesday that it has raised $7.5 million in a Series B round to fund its plans to bring tiny wireless energy sensors to data centers. The idea is to measure, collect and use data on electricity use and heat to help data center managers save on their power bills.

It's a line of business that other startups are eyeing, including Santa Clara, Calif.-based Power Assure, San Jose, Calif.-based Cassatt and Folsom, Calif.-based SynapSense (see Keeping Facebook From Frying).

But Bob Davis, Sentilla's CEO, claims that his company's software and "Sentilla Mini" chips and wireless transmitters can do the job better, by monitoring data center equipment on an piece-by-piece basis and collecting that data in a form that can be analyzed and eventually used for automated, moment-to-moment efficiency improvements.

"Most of what is being done is being done at a rack level," Davis said of other energy-monitoring efforts. "We can do this at every single port, at every single piece of equipment."

The other vendors, no doubt, would disagree. Many actually perform very similiar functions. Still, Sentilla is getting customers: since launching its energy-management line of business in May, it has landed three data center customers, and intends to announce them by the end of this month, Davis said. Given that data centers use about 1.5 percent of the electricity in the country and 2.5 percent of the electricity in Northern California, he sees a huge market for helping them get more efficient.

Sentilla's founders have been working since 2003 on software that can control tiny computers that can collect and transmit data wirelessly to a central point where it can be monitored and put to use. In 2006 the company raised $6 million in a Series A round led by Onset Ventures and Claremont Creek Ventures, the same firms that funded the company's second round this month, to develop its Sentilla Mini.

Initial tests of Sentilla Mini-enabled sensors included applications in warehousing and logistics, agriculture and aluminum smelting, he said. It was this last application – monitoring the heat put out by smelters and comparing it to the electricity going in to discover when the smelters were no longer running at optimum efficiency – that gave Sentilla the idea of going into the data center business.

"From our point of view, they look and act very similarly," he said, since both measure heat and electrical current. But from a business opportunity standpoint, they couldn't be farther apart.

"There are only 20 aluminum plants in the word, but there are a lot of data centers, and billions of dollars in energy costs," Davis said – and those data center power costs could grow to as much as $7.4 billion a year for 100 billion kilowatt-hours of power demand by 2012, according to a The U.S. Environmental Protection Agency analysis (see Data Centers Could Hit 'Resource Crisis').

Sentilla launched its energy management line of Java-based software in May, receiving some publicity through a test at San Francisco's Moscone Center for Sun Microsystems' JavaOne 2008 conference.

The company installed about 200 Sentilla Mini-enabled sensors throughout the conference center to monitor power usage, humidity and temperature, as well as infrared sensors on door frames to track how many people entered and left rooms where sessions were being held, and displayed the resulting data to conference attendees.

That leads Davis to identify building energy use monitoring and management as a potential future market for Sentilla.

"These devices that we have are perfectly well suited to provide the same kind of intelligence at the HVAC (heating, ventilation and air conditioning) level," he said. "We see the movement into data centers as an entrée into a commercial facilities focus. That's one of the things I put into the stay-tuned category."