Sentilla originally developed its technology for use in the manufacturing industry, where it's used to measure the energy consumption of large aluminium smelters, Davis said. Last year it adapted the technology for the data center, where reducing energy use has become a top priority for many companies.

"The thing we're told time and again by various sorts of customers is that they want to know what's happening at the equipment-level." Davis said.

Sentilla is one of several startups taking a variety of approaches to cutting energy use in data centers. SynapSense uses wireless sensors around the data center to create heat and humidity maps that can help manage cooling systems. Another, Cassatt, develops software that balances server workloads and turns machines off when they're not in use.

"I think we differentiate ourselves with the granularity of what we measure,"Davis said.

Sentilla plans to work with partners to broaden how its technology can be used. It could work with load balancing or virtualization software, for example, to steer workloads toward the servers that are operating the more energy-efficiently, he said.