A new report from the Brookings Institution seeks to get its arms around the nebulous “clean economy,” and finds that Maine’s growth in the sector has tracked national trends, surpassing U.S. rates over the past few years.

“Sizing the Clean Economy: A National and Regional Green Jobs Assessment,” was released Wednesday by the nonpartisan Washington, D.C. think-tank and found Maine had 12,212 “clean jobs.” It defined “clean” in a broad way, in 39 low-carbon and environmentally oriented industry segments ranging from work done on wind turbines to ocean energy, development of sustainable building materials to mass-transit workers and wastewater treatment experts. Nationwide in 2010 there were 2.7 million clean jobs, Brookings found.

From 2003 to 2010, Maine added 2,914 such jobs, growing by 4 percent annually. That job growth closely tracked the national rate until sometime between 2008 and 2009, when the state rate overtook the national growth rate, which was 3.4 percent from 2003 to 2010.

Not surprisingly, taking into account Maine’s relatively small population of 1.3 million people, in terms of the overall size of the clean economy Maine ranked 44th among the 50 states and the District of Columbia.

Among the sample Maine employers Brookings pointed to were Cianbro Corp. of Pittsfield, for the firm’s green architecture and construction services; Casco-based Hancock Lumber Co., for providing sustainable forest products; Portland’s Ocean Renewable Power Co., which is working on tidal power Down East; Tom’s of Maine Inc. of Kennebunk, which provides green consumer products; and Portland’s Woodard & Curran Inc., a professional environmental services firm.

For John Ferland, vice president of project development at Ocean Renewable, the numbers touted in the Brookings report and the impact of the green economy overall weren’t surprises.

The company recently finished beta testing its tidal power technology in Cobscook Bay. It has said it has injected more than $8 million into the Maine economy developing the technology, creating or retaining more than 100 jobs, with a supply chain that extends into 13 of Maine’s 16 counties.

“We’ve seen during our development that we do have an enormous impact on the economy, even prior to being in commercial operation,” said Ferland. “We’re bringing into ocean energy a lot of different industries and services; it becomes part of what they do.

“We represent a new industry that not only is creating the types of jobs that didn’t exist before, but is providing opportunities for traditional jobs that are being applied in a different way.”

Ferland has had a long career in the green sector. In the 1980s he worked in communications around environmental permitting and was president and CEO of Coastal Strategies Inc., a marine-use policy and planning firm. From 2001 to 2008, he was president and CEO of both the Environmental and Energy Technology Council of Maine and of the Maine Center for Enterprise Development, an environmentally focused incubator at the University of Southern Maine.

“It’s all coming to the forefront now, [the growth] that those of us who have worked in it for years understood could happen,” said Ferland.

The green economy, the Brookings report suggested, is growing because of increased concerns over environmental issues as well as a “sharpening need for resource security.”

The U.S. consumes almost 19 million barrels of day, and half of this is imported, the report noted. With fluctuating oil prices, almost constant tension in the Middle East and other concerns, countries are seeking to diversify their energy portfolios, the report said.

Thomas Francoeur, senior vice president and business center manager for consulting services at Woodard & Curran, said those global challenges play out locally. The challenging economy and increased environmental concerns have created an environment where developers, businesses and governments want to be green — for the planet and to save money.

“There’s a general acknowledgement now that resources just aren’t limitless and they need to be managed — that’s just naturally working into the way we deliver our services,” said Francoeur.

Woodard & Curran is a full-service engineering firm employing a total of 600; about 200 in Maine.

Another reason for growth is the “worldwide aspiration toward economic transformation.”

“The clean economy matters, in short, because it interacts with nearly every aspect of the rest of the economy and is emerging as a site of rapid technological and process innovation worldwide,” the authors wrote.

There is a global race to develop these technologies, the report said. Between 2004 and 2010, roughly $1 trillion in investment capital globally went into clean energy segments alone. Yearly investment levels nearly quintupled from $52 billion to $243 billion.

Mark Muro, a senior fellow at the Metropolitan Policy Program and a co-author of the report, said in an accompanying release that America’s top economic competitors, including China and Germany, have lead the way in supporting clean economy development.

“We risk giving away what should be a significant competitive advantage for the U.S.,” Muro said. “In 2004, for example, Chinese clean energy project financing trailed America’s. By 2010, China’s investment was more than double ours. Meanwhile, we are seeing U.S. companies losing market share at home and abroad.”

In the United States, while the clean economy grew more slowly in raw numbers than the national economy between 2003 and 2010, newer “cleantech” segments produced “explosive job gains,” the report said. Brookings said those segments grew by 8.3 percent during this period, though from smaller bases.

To put the overall size of the sector in perspective, while the clean economy encompasses 2.7 million jobs nationally, the information technology-producing sector employs 4.8 million. Fossil fuels are at 2.4 million and biosciences employ 1.4 million.

The clean economy also has a strong manufacturing component, with about 26 percent of all clean economy jobs in that area compared to 9 percent in the broader economy, Brookings noted.

In Maine, the average wage for jobs in the sector was $36,460 annually. About 70 percent of the jobs were “green collar” jobs, or environmental blue collar. That compares to 43 percent nationally.

The majority of Maine’s clean jobs were in three main segments — conservation (2,287 jobs), waste management and treatment (2,224 jobs) and public mass transit (1,408). The fastest growing segments were biofuels-biomass, air and water purification technologies, professional energy services, sustainable forestry products and green architecture and construction services.

Digging deeper into the numbers, 3,591 of the state’s clean jobs were based in the greater Portland area, which encompasses Portland, South Portland and the Biddeford area in the Brookings report. The Lewiston-Auburn area had 747 jobs total and Greater Bangor had 1,247. The rest of the jobs were in other areas throughout the state.

The report also focused on the importance of developing regional clusters around an expertise. In Maine, one such cluster might be development of wind power expertise – especially in the nascent area of deep-water offshore wind. That’s an area where the University of Maine is working in partnership with Maine companies such as Cianbro, Bath Iron Works and others.

Paul Williamson, director of the Maine Wind Industry Initiative, said Maine has focused on developing a domestic market for products and services. As that expertise and supply chain is developed here, it can also be exported. For instance, he said, Woolwich-based Reed & Reed, a construction firm, is now bidding on wind development projects across the nation.

“This is a grand opportunity for our state, somewhat rare … to have this much potential from a central source of job creation,” said Williamson.

The green collar jobs in the overall green industry require a degree of specialization and additional training, he noted. And a lot of the growth he’s seeing in Maine comes in the area of intellectual and technology jobs, such as engineering and environmental consulting.

One of the important factors to consider, said Williamson, is that for the past few decades, most states concentrated on taking jobs from other states — it was a transfer of employment, not necessarily the creation of new jobs.

“In this case, we’re creating new jobs,” he said.

In suggesting what is needed to support the sector, Brookings urged “smart, strategic decisions and investments” from the public as well as the private sector.

“The United States should be at the vanguard of developing and deploying new, clean technologies,” said Bruce Katz, Brookings’ vice president and director of the Metropolitan Policy Program, in the release. “The brutal truth is, unlike our global competitors, we have no strategic framework for expanding the clean economy. We have too few financing tools, and we provide too little support for necessary innovation. This is not an area where the public sector needs to get out of the way.

“Government leaders, at all levels, need to get in the game.”