Michael P. DeFrancesco, a consulting civil engineer from Exeter, speaks at a public hearing yesterday at the Kendall Dean School, in Slatersville, about the planned hydroelectric plant.

The Providence Journal / Bob Thayer

NORTH SMITHFIELD — It’s a glorified, high-technology water wheel, not a Trojan horse.

That was the message representatives of the group that wants to build a small hydroelectric generator next to one of the Slatersville dams brought to a public forum on the project yesterday.

A steady line of questioning that emerged at one point was over whether the planned facility would have the capacity to be powered by natural gas or fuel oil. Engineer Michael P. DeFrancesco and environmental consultant Scott Rabideau repeatedly stated that the only source of power for the plant’s turbines would be water.

That seemed to mollify some of the two dozen people at the meeting in the Kendall Dean School. The session was called as part of the early stages of the project’s review by the federal government for a license to run the plant.

Though the plant being proposed by Slatersville Hydro LLC is in such early stages that no specific drawing has been produced, DeFrancesco said the final result, if built, would be a 20- or 30-foot-square one-story building. The structure would be built along the reservoir by the dam near the intersection with Route 102 and Main Street. It would be in a ravine between the reservoir and Main Street, whose depth would probably obscure the building from the street, DeFrancesco said.

The meeting at Kendall Dean was intended as an introductory session to find out any initial concerns, DeFrancesco and Rabideau said. Even if things go smoothly, DeFrancesco said the plant was probably two years or more from actual construction.

Many of those at the forum were veterans of the 2001 fight against the Indeck company’s plant to build a gas-fired steam plant on the other side of the reservoir. Town Council President Linda Thibault, a leading opponent of that project who later moved on the Town Council, said the Slatervsille Hydro proposal seemed like a different type of power plant.

The Indeck plan was intended to use steam-power turbines to generate electricity. Its boilers would have been powered from a natural-gas line that runs through town. Residents were opposed for many reasons, but the Indeck smoke stack and its steam plumes, as well as safety worries from the natural-gas boilers were among the most often mentioned.

Some residents at yesterday’s event said they were worried that the developers were trying to get a building built as a water-powered plant only to have the ability to switch it to gas or fuel oil after it is in place, Thibault said.

Slatersville Hydro’s plant is different because it is designed in some ways along the same lines as the water wheels that powered the 1800s mills in the village. Water will be channeled into the plant building, flow through the turbine and make it spin. The spinning turbine will, in turn, power a generator that will produce the power. No fuel will be burned and no steam will be produced. DeFrancesco said the equipment would be virtually silent from the outside.

“If it’s what it is,” Thibault said of the plant described at the meeting, “it’s good.”

DeFrancesco, who has done feasibility studies for hydroelectric plants in Manville and at other Slatersville Reservoir dams, said the plant that was being contemplated for the site would generate 1,100 to 1,200 megawatts of power a year. Its level of output would vary with the water level in the reservoirs, he said. When water is plentiful, it will run; when the water runs low, the turbines will stop.

The plan is that the plant would be connected to the National Grid lines that run down Main Street in Slatersville, contributing its electricity to what is available to customers throughout the utility’s area. The power-plant operators, affiliated with Holliston Sand and Gravel, would get credit against their electric bills for what they provided to the grid and be paid for the excess.

Andrew Dzykewicz, state commissioner of energy resources, said a similar kind of deal might be struck to power the town’s street lights.

The Slatersville Hydro project fits into the state’s goal for increasing the percentage of electric generation by renewable sources — such as water or wind — to 16 percent by 2014. While the bulk of that goal will probably be reached via large-scale “home run” wind- and wave-generation project, he said, small plants such as Slatersville Hydro’s still have a role to play.

“We also have to hit a lot of singles,” he said. “We get enough singles, we get some more runs.”

jhill@projo.com