N.H. company wants to harness electricity from tidal river turbines

PORTSMOUTH, N.H. – A company called NH Tidal Energy Co. is proposing to produce electricity using the power of tides in the Piscataqua River.

The proposal filed with the Federal Energy Regulatory Commission calls for 50 to 100 turbines to be submerged in the river as it passes through Rockingham and Strafford counties in New Hampshire and York County in Maine.

The underwater turbines would contain rotating propeller blades that move with the incoming and outgoing tides to generate power.

Tidal projects have long drawn interest in New England. Earlier this month, FERC was alerted to a possible proposal for a tidal power project in Little Machias Bay in Maine.

Federal officials say the Piscataqua project could general 8.76 gigawatts per year from each turbine. Public Service Co. of New Hampshire spokesman Martin Murray said tidal river turbines typically produce roughly the same amount of power as the average wind turbine.

City environmental planner Peter Britz has asked for more information on the proposal.

“It sounds like a neat project,” he said. “I’m optimistic it could be a good use.”

Britz said he has some concerns about what it would look like from the river and whether it would interfere with fish passage and the movement of large ships.

Murray said Public Service would be required to connect such a project to the grid, but not to purchase the power. He said his company has had only preliminary discussions with the project planners.

NH Tidal Energy is seeking a federal permit that, if granted, would extend 36 months and include time for financial analysis, engineering studies and environmental impact.