FirstFuel has raised $8.5 million in a Series B round aimed at expanding its remote building analytics to new markets -- and, if the round’s lead investor is any indication, that could include Europe.

That’s because giant European utility E.ON is leading the investment round, joining existing investors Battery Ventures, Rockport Capital and Nth Power. The funding round brings total investment in the Lexington, Mass.-based startup to $21 million, and is aimed at fueling growth and development of its Remote Building Analytics software-as-a-service platform.

FirstFuel has several large U.S. utilities using its technology, including Pacific Gas & Electric, and has also landed several government partners, including the federal General Services Administration, Washington, D.C.'s Department of General Services, and the Department of Defense’s Environmental Security Technology Certification Program (ESTCP).

Now it has a strategic investor to offer it entree into projects in Europe, where regulations are set to push efficiency on a broad scale. In a Tuesday statement, Urban Keussen, senior vice president for technology and innovation at E.ON, said the utility is planning to “work with FirstFuel as both an investor and a partner for the future,” though the release didn't provide any more details.

FirstFuel's technology relies on analyzing energy meter data collected from utilities, along with weather data, building location information and characteristics, and other site-specific information, and then applying what CEO Swapnil Shah calls its “inverse modeling” approach. It’s one of a number of “virtual energy audit” software providers promising a much cheaper way to discover and prioritize energy waste in buildings, or across entire real estate portfolios (others include Noesis Energy, Retroficiency, Sparc, and Energy Results).

As of November, FirstFuel had analyzed over 700 million square feet of commercial building space, which can help customers take low or no-cost actions to reduce simple energy waste (e.g., leaving lights and HVAC systems on overnight, incorrectly setting operating parameters), as well as prioritize which buildings offer the best return on investment for more involved efficiency retrofits. 

It’s all part of the growing world of intelligent energy efficiency, which stretches from early-stage companies like SCIenergy, Lucid, WegoWise, Agilis, Switch Automation and BuildingIQ, to energy services giants like Honeywell, Johnson Controls, Siemens, Trane and Schneider Electric. Demand response companies like EnerNOC, building energy management and analytics companies like Ecova, EnergyCAP and eSight Energy, and IT systems integrators like Wipro are also moving into building efficiency.

All are targeting the massive opportunity in buildings, which can waste up to a third or more of their total energy use. All face the challenge of making efficiency investment competitive with alternative opportunities for capital spending by building owners, coming up with ways to manage the split incentives that bedevil efficiency projects, and of course, scaling up their solutions to meet the needs of customers at the portfolio level. 

Utilities, in turn, have an incentive to better understand their customer energy profiles to optimize their efficiency spending, increase customer satisfaction, and perhaps incorporate real-time, adaptive building energy controls into serving their grid needs. Customer-facing systems are particularly important for utilities in deregulated markets, which must fight to land and retain customers with a whole set of offerings that go beyond simple sales of electricity and natural gas -- including efficiency services.