PORTLAND – A Portland-based tidal energy company is preparing to install a new power-generating system later this month on the ocean floor in Down East Maine.

Ocean Renewable Power Co.’s first turbine generator unit will be able to produce enough electricity to supply 20 to 25 homes, said John Ferland, vice president of project development.

An underwater cable located roughly 3,700 feet from the shore of Lubec will transmit the power from the underwater station to Bangor Hydro-Electric Co. customers on the mainland.

The turbine generator, which Ferland says resembles a paddle wheel on a Mississippi River steamboat, will be held to the ocean floor by a steel support frame that will have pilings driven into the bottom. The turbines can be lifted out of the water — they will be about 100 feet below the ocean’s surface — for maintenance.

“How this will look on the water and the landscape is how Eastport-related jobs have looked throughout time,” Ferland said. “There will be boats on the water (above the underwater turbine site) and construction barges. It will look like a working waterfront project. It won’t be disruptive.”

With its federal license now in hand, Ocean Renewable Power Co. can install its first grid-connected power unit at a 60-acre site in Cobscook Bay — the nation’s easternmost tip.

The first unit will be hooked up to the grid this summer, and four more units will be installed next year, the maximum allowed under the federal permit.

Chris Sauer, president and chief executive officer of Ocean Renewable, said that eventually, Ocean Renewable hopes to install more units to bring its electrical output to 4 megawatts at sites off both Lubec and Eastport.

Ocean Renewable holds permits for three sites in the area, one of the world’s best tidal sites, where twice a day the tide rises and falls 20 feet.

All told, the company sees up to 50 megawatts of tidal power potential in the Eastport and Lubec areas, enough to power thousands of homes, Sauer said.

“It’s never going to be the dominant power-generating resource in the state of Maine, but it’s going to be a significant contributor,” Sauer said.

The Ocean Renewable turbine generator unit self-starts when the tidal current reaches 2 knots, and is designed to produce up to 180 kilowatts under ideal circumstances. On average, however, it’ll produce 60 kilowatts at the installation site in Cobscook Bay near Seward Neck in Lubec, Sauer said.

Once it’s completed, the full array of five of those turbine generator units will produce about 300 kilowatts under the pilot project license issued last week by the Federal Energy Regulatory Commission. The completed pilot project will produce enough electricity for about 100 homes.

A month earlier, FERC issued a similar license for Verdant Power, which hopes to produce tidal energy from New York City’s East River. Verdant’s tidal power design looks a lot like a wind turbine, only it’s underwater.

Ocean Renewable expects to begin work later this month on underwater installation of a heavy steel base. From there, the turbine generator unit will be mounted on top.

Previously, the company’s prototype was tested in the waters off Lubec and Eastport. It was mounted under a barge and lowered under the water for testing.

Ferland said the company’s corporate offices are located in downtown Portland. It has partnered with Perry Marine & Construction, an Eastport-based company that will be responsible for most of the project’s fabrication needs.

“It’s a start,” Ferland said. “What we need to do to make our industry successful is to do our project right the first time and do it at a scale that we can work with.”

Officials in Canada are watching the Maine project with interest. By 2014, Ocean Renewable and Nova Scotia-based Fundy Tidal Inc. hope to install the same units in waters off Nova Scotia, where Bay of Fundy offers even greater tidal power potential, officials have said.

The Coast Guard will set safety rules to ensure that fishing and recreational boats can safely operate despite the presence of a barge, platforms with cranes and boats with divers.