Energy management firm ConsumerPowerline said Thursday it has landed $17 million in funding.

The round, which was led by Expansion Capital Partners and completed Monday, is the New York City-based company’s first since it launched in 2000 with more than $300,000 in angel funding.

“We [had] not raised another penny because we’ve been pretty consistently cash-flow positive,” said Mike Gordon, ConsumerPowerline’s president and acting chief executive.

The bulk of those revenues have come from the company’s core business, demand-response, a transaction in which large energy users reduce their energy consumption during impending power outages and sell that power, dubbed “negawatts,” back to utilities and other energy companies at peak electricity rates.

Demand-response is an increasingly competitive space. EnerNoc and Comverge, both of which went public this year, are also in the business, estimated by Mr. Gordon to soon be a $2 billion market in the United States alone. Despite the competition, there’s still a lot of elbow room. Mr. Gordon estimates, for example, the combined annual revenues for the three companies come to “shy of $100 million.”

ConsumerPowerline currently is involved in helping sell 200 megawatts of negawatts a year, according to Mr. Gordon, and that volume is expected to increase.

“The growth has been very rapid,” Mr. Gordon said. “It’s been a good solid 40 percent per year. We expect that to be ramped up further with this investment.”

The infusion will be used to expand the reach of the company’s demand-response business into New England; and states such as Maryland, New Jersey, and Pennsylvania; and California.

ConsumerPowerline also plans to use the funds to bulk up its energy efficiency and renewable energy services, which operate on a similar model but are distinct from demand response.

“There are entirely new markets that are opening up around efficiency and renewables,” Mr. Gordon said. “Ultimately, demand response is not the biggest of those markets.” The entire market for energy management services, he estimates, is upwards of $17 billion in the U.S.

Much of that depends, in part, on regulations requiring power suppliers to buy from renewable sources or to adopt or otherwise support energy efficiency measures.

ConsumerPowerline’s efficiency services will focus on the market in New York, where sellers of power will be required to buy energy efficiency certificates sometime in the next year, Mr. Gordon said.