Hara came out of stealth a little less than 16 months ago, but it seems to be on its way to becoming a fixture of the industry.

The company, which has created a software platform that monitors the consumption of water, gas, electricity and other resources in an effort to trim consumption, has signed up Philadelphia as a customer. Philadelphia's goal is to reduce power consumption by 30 percent by 2015, as well as to insulate the city a bit better from power price fluctuations.

Hitting these targets could help the city save $10 million a year. Not all of the gains will come from the software, but it will help.

Philadelphia is the fourth municipality to become a customer and the 40th overall, says Chris Farinacci, Hara's chief marketing officer. The company will also have a major new release of its software in about a week or two.

Other customers include Apple, Brocade, News Corp., and Safeway. The rapid increase in signed clients has made it both one of greentech's prime acquisition targets and one of its incumbents.

What's the secret behind Hara's growth? Other companies like SAP and ENXSuite (formerly Carbonetworks) initially positioned these kinds of applications as carbon accounting platforms. By contrast, Hara said it wanted to target corporate metabolism and reduce utility bills. Out of the gate, Hara was selling a product that didn't rely on regulations and policy initiatives. With cap and trade regulations moving continually on the horizon, carbon software became less urgent. (Tracking Level 3 cheesesteak emissions is not part of the Philadelphia plan.) In a sign of the times, ENXSuite repositioned itself as a platform for tracking resources in June.

Another factor: corporations apparently find the software useful, which is rarer than you might think with enterprise software. The amount of data in the system has doubled in the last three to four months, an indication that customers are studying their functions in greater depth.

Now for the risk factors. Hara, like all enterprise software companies, has to save customers more money than the system costs. Some outfits are taking an ESCO approach and charging customers a fee that approximates a percentage of what the software costs. Hara has variable programs. In deals with cities, it charges a fee based on population. In other words, expect ongoing business model adjustments to occur here.

Competitors will increasingly target its customer base. SAP just introduced Carbon ImpactOnDemand. It counts Autodesk and Fisker Automotive as customers.

Hara recently has also seen some execs depart for competitors, but Farinacci says that the company continues to grow. A little more than a year ago it had 20 employees. Now 60 work there.

"We've tripled the company's workforce in the last year," he said.