Sentilla

Sentilla

Entrepreneur: Joe Polastre, 28

Funding: $13.5 million from Onset Ventures and Claremont Creek Ventures

Sentilla makes technology designed to guard against wasteful IT energy use. The startup's sensors and software detect how much electricity is used by servers, disk drives, and other data-center equipment, then suggest such money-saving measures as switching off idle machines or combining the work of several computers onto one. "By reducing your energy, you're immediately reducing your operating expenses," says Polastre, Sentilla's co-founder and chief technology officer. Sun Microsystems (JAVA) and the Mozilla Foundation, the maker of Firefox, have bought in, as have companies in other energy-intensive industries, such as metal working.

Lessons learned: "You have to adjust your business model as quickly as possible," says Polastre. "A lot of companies aren't able to articulate [return on investment], but that's what people are buying, particularly in the IT space."