Mike Kennedy was tired of his career.

A few years ago, the Kensington resident left his real estate development job and started looking at the growing field of green jobs. He looked into solar installation companies, and even green funerals — which involves burying a body and letting Mother Nature take over. The idea of a green cooperative — bringing suppliers and clients under one tent — was where he landed.

"I did some surveying in the area, and found out that people are really interested in going green, that we've reached this tipping point where people understand the cost benefit of it," he said. "It got me thinking."

So, in October, he launched the Maryland Energy and Sustainability Cooperative, a Bethesda group that vets green suppliers and contractors, and assembles them so they are more accessible to prospective clients. The idea is simple: Individuals join the co-op and pay a $500 fee that allows them to receive discounts at all the vetted suppliers and contractors. Member suppliers include home energy auditors and weatherization experts, geothermal installers, remodelers certified by the U.S. Green Building Council's Leadership in Energy and Environmental Design program and even a green stationery company.

Kennedy spent the last few months trailing all the contractors, making sure they were reliable and did good work.

Since the group launched, 13 companies have signed on, most from Montgomery County. Each company must also pay to be a member, making them a vested partner in the co-op, Kennedy said.

Individual members started signing up two weeks ago, and already 23 people have become part of the co-op. They pay the one-time $500 fee and a $35 yearly maintenance cost. When compared with the discounts of up to 15 percent they receive at certain businesses, though, Kennedy said the cost is minimal.

John Spear, president of Green Home Pro, a Gaithersburg design company that focuses on geothermal sales and installation, said the co-op not only provides leads and a built-in customer base but benefits the community as a whole.

"People are taking their money and hiring a local firm to do work that could otherwise go to some national company," he said. "Then they have a little more disposable income, which might go to a restaurant or a movie."

Spears said the co-op is also a chance for local companies to network and exchange ideas.

Rex Wright, chairman of the Maryland branch of the nonprofit U.S. Green Building Council, said the idea is new to him, but one he welcomes.

"One of the problems we have with our industry is people finding all the services they need," he said. "People have had to find the businesses themselves. Being able to connect those businesses is important to growth."