Cutting holes for windows at Truth Box are, from left, Giles Hoyler, Saul Estrada and Matthew Smith, all of Stack Design.

The Providence Journal / Bob Thayer

PROVIDENCE — When Alteris Renewables decided to add another office in either Rhode Island or Southeastern Massachusetts, it considered Fall River, New Bedford and Bristol.

Then, early this year, the rapidly growing clean-power company turned its sights on Providence. Alteris knew the city well after installing solar panels on green developer John Jacobson’s earth-friendly office building on Wolcott Street.

In February, Mark Nelson, Alteris’ vice president for business development, sat down with Jacobson and Mayor David N. Cicilline to discuss the city’s attributes. He was attracted to the energy-efficient space Jacobson was offering in the Wolcott Street Eco-Office. He liked the easy access to the highways, too.

And Nelson was intrigued by Providence’s plan to create a green technology hub around Valley and Promenade streets in the Olneyville section of the city. It seemed a good fit for his company, which installs wind and solar energy systems throughout the Northeast.

“It wasn’t the deciding factor, but did it contribute to our decision? Yes,” said Nelson of Alteris’ decision to move into the office with 17 employees.

Just as Providence is working to transform the Jewelry District into a center of knowledge-based businesses in health care and medical research, the city now wants to turn what was once a heavy industrial area on either side of the Woonasquatucket River into a so-called green corridor.

At least a half-dozen companies in the fields of renewable energy, sustainable building and energy efficiency already have offices there with more than 200 workers. They include Umicore, a manufacturer of components for solar panels; Ecolect, an online green materials resource center; Truth Box, an architecture firm dedicated to green building; and CTG Energetics, a global consulting firm that focuses on sustainability.

DURING A TOUR of the area this week, Cicilline said those businesses are creating a tipping point for the future development of green industries in Providence.

“It’s a part of the city where we’re really starting to see the green economy grow,” the mayor said. “We see it as an opportunity to create jobs, grow our tax base and protect our environment all at the same time.”

But other cities and states also see opportunity in green technology despite reports from economists that the sector will only be a small part of the economy for the foreseeable future. The Obama administration is heavily promoting renewable energy. States in the Southwest are investing in solar power, while states in the Midwest are attracting manufacturers of land-based wind turbines.

Even in Rhode Island, Providence has competition. Green-tech businesses are growing in other parts of the state. SGE, an engineering company that consults on wind-power projects, is headquartered in Middletown. Applied Science Associates, a company that has done wind feasibility studies throughout Rhode Island, has offices in South Kingstown.

And the state is working to create a green-industry hub at Quonset Point, in North Kingstown, where the developer Deepwater Wind plans to stage offshore wind farms proposed in Rhode Island and other East Coast states.

J. Michael Saul, interim executive director of the state Economic Development Corporation, said he believes that the green sector will become a large enough part of the economy to create opportunities around Rhode Island. There may be potential for multiple clusters of green businesses in the state, he said, and Providence is smart to market itself as one of those centers.

MATT GRIGSBY, cofounder of Ecolect, said, “It positions Providence to attract socially minded entrepreneurs.”

His company, which opened an office in the area two years ago, has already seen the benefits of being near like-minded businesses. Ecolect is collaborating with the nearby William Kite Architects on a sustainable prefabricated housing project.

Peter Gill Case, the owner of Truth Box architects and developer of a modular office building, sees the beginnings of a green district in Olneyville.

“It’s always difficult to call a movement a movement,” he said. “But there are certainly pieces moving into place.”

The tour, led by Cicilline, stopped at the United Natural Foods headquarters in the former American Locomotive Works complex. The company is the leading organic food distributor in the country, and its office, built with green materials, opened in October. Three weeks ago, the company installed the largest solar array in the state on its roof.

The mayor also took visitors through the Wolcott Street Eco-Office, which houses Alteris’ financial unit and call center. The 1891 building was a former jewelry factory that Jacobson renovated last year. It’s now a sleek structure that generates all of the energy it uses through the sun.

Jacobson said he thinks a large part of the green industry in Providence will focus on making the city’s large stock of mills and other older buildings energy efficient. He pointed to the Steel Yard, a former brownfields site on Sims Avenue that is being redeveloped using sustainable building techniques. And other developers in Olneyville are taking foreclosed properties and making them green.

“In general, in these economic times, it’s much cheaper to build green using an existing building than to build new,” Jacobson said. “The economics do work out.”

akuffner@projo.com