June 9, 2010 - tidal power in Maine: the Passamquoddy Power Project

Wednesday, June 9, 2010

Maine's historic wood and stone tide mills were just going dark in the 1930s. At the same time, larger tidal power projects were in the works. Chief of these was the Passamaquoddy Power Project, a large project designed to generate 300 to 500 MW of capacity.

In 1919, having returned from dam siting and building in South America, Dexter P. Cooper took some rest and relaxation on Campobello Island, just over the New Brunswick border from (and only accessible by road from) Lubec, Maine. As the August 1935 article in Popular Science put it:
With nothing to do, Cooper spent whole days watching the tides swirl past the island. He calculated the billions of horsepower going to waste. As a sort of hobby, he began imagining ways of putting the rising and falling water to work. In the end, he became convinced of the entire practicability of harnessing the Fundy tides.

What Cooper envisioned was the construction of five huge dams connecting various points and islands near the junction of Passamaquoddy Bay and Cobscook Bay. Cobscook Bay would be effectively walled off from Passamaquoddy Bay. As the Bay of Fundy's tide rose in Passamaquoddy Bay, the topography would make Passamaquoddy fill much faster than Cobscook. Once a five-foot head was built up, the penstocks would be opened and Passamaquoddy would fall down into Cobscook, spinning turbine generators along the way. Under expected conditions, the head could build up to as much as 18 to 23 feet. At low tide, gates would open and equalize the water levels.

Tidal projects have always had to deal with the effects of lunar time changes. Each night, the moon passes its zenith about 50 minutes later than the night before. In older times, this meant that the milling could only take place for part of the day, and not necessarily at convenient times. The Passamaquoddy project included an early pumped storage reservoir. A 180,000 horsepower pumping station at Haycock Harbor was to pump seawater into a 13,000 acre reservoir at 130' above sea level.

If you've ever been to Lubec, or if you follow tidal power projects, you probably know that the Passamaquoddy Power Project was never completed. I'm looking at the "why", to see what we can learn from history.

1 comment:

Infinite Typing Monkeys said...

In the 1930s, the United States under President Franklin Roosevelt appropriated funds to construct an “All-American” project based in Cobscook Bay and intrinsically connected to Passamaquoddy Bay. In this case, Cobscook Bay was defined as the high pool and the generation of electricity would have started shortly after high tide once an adequate elevation differential was established between impounded waters in Cobscook Bay and the receding waters of the Bay of Fundy. After two or three years of construction activity, the project was suspended due to concerns associated with economic feasibility and the inability to fully integrate electricity into a regional grid. Other factors included opposition from private utilities for public power and political complications."

Source: http://www.mainetidalpower.com/

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