July 22, 2011 - Nova Scotia tidal energy: past, proposed, and future

This week's story about a possible hydrokinetic tidal energy project in Nova Scotia's Bay of Fundy reminded me of large-scale tidal projects that have been proposed in northeastern North America over the years.  Chief among these may be the Passamaquoddy Power Project proposed in the early 20th century, but the PPP wasn't the only grand project dreamed up.

Sunset over the harbor at Five Islands, Georgetown, Maine.

One tidal project floated in the early 1980s involved developing up to 6,000 MW of tidal power capacity through two dams in Nova Scotia.  One dam would have blocked off Shepody Bay (the arm of the Bay of Fundy reaching toward Moncton and the Petitcodiac River near the Nova Scotia - New Brunswick border), while the other would have walled off part of Minas Basin between Cape Blomidon and Parrsboro.  Neither of these dams was ever built, although the tidal energy resource of Minas Basin continues to draw interest.

One reason may be the impact of the projects on coastal communities along the Bay of Fundy -- and in fact well out into the Gulf of Maine.  A news article from 1981 suggests that these tidal dams would have increased the tidal range in Portland, Maine -- about 300 miles away -- by up to 18 inches.  This increase in tidal range could have negatively impacted coastal communities, eroding soil, causing property damage, and tidal flooding.  By contrast, the article suggested that the Passamaquoddy project or a smaller one proposed for Half Moon Cove would not raise tides elsewhere.

These projects may not have been built, but with Nova Scotia's new community-based feed-in tariff, developers of in-stream tidal projects can expect $652 per MWh for qualified energy produced in the province.  Will Nova Scotia's feed-in tariff lead to more tidal projects in the Bay of Fundy?