Inflatable flashboards at hydro dams

Dam owners are increasingly enhancing their revenue by using inflatable flashboards to optimize their hydroelectric production.  This new technology offers dam owners and operators increased safety and increased hydroelectric generation, as well as opening the door to tax credits and other incentives.

Flashboards have traditionally been a palisade of wooden boards inserted into the top of a dam's crest.  Flashboards increase a dam's capacity to hold water.  They are typically used seasonally in temperate climates, and are removed before winter.  Flooding or even high water can wash flashboards away, impairing the dam's ability to hold water until they can be replaced.  Replacing flashboards can entail danger to personnel, and it might be a long time before water levels recede enough to allow safe reinstallation.  In the meantime, a dam's ability to safely store water can be reduced.


Inflatable flashboards allow operators to increase or decrease the effective height of the flashboard system remotely.  The ability to quickly and safely restore pond elevation after a high flow event translates into increased electricity generation.  For example, inflatable flashboards at the Deer Rips - Androscoggin 3 Hydroelectric Project on the Androscoggin River in Lewiston and Auburn, Maine, have been calculated as likely to increase electric generation by 4.56% compared to a historical baseline.

This incremental hydropower generation can be valuable to the dam owner.  Not only does it allow the facility to produce more electricity, but it may also qualify the project for federal and state tax incentives.  For example, Section 45 of the Internal Revenue Code provides a renewable energy tax credit to owners or operators of qualified renewable electric generation facilities.  That credit was extended to the incremental production gains from efficiency improvements or capacity additions developed between 2005 and 2013.  Developers can ask the Federal Energy Regulatory Commission to certify a historic baseline of power produced at existing dams, as well as the incremental increase in hydropower production due to qualifying investments.  Once FERC has issued this certification, dam owners can provide that to the Internal Revenue Service to receive the tax credit.

July 19, 2010 - life on a Maine island

I've just returned from a visit to one of Maine's offshore islands. Life on a small island can seem fundamentally different: the pace of life is driven by the tides and boat schedules, and fog can often replace the mainland's heat. It was a good place to think about energy policy, and history, and where we can go from here.

More updates to follow regularly.

Brief news recap:

Friends of Merrymeeting Bay (FOMB) have provided 60-day notice of intent to sue the owners of four Maine dams under the Clean Water Act over issues relating to Atlantic salmon. FOMB have a history of legal activism over fish (including eel) passage at dams in Maine, particularly in the Merrymeeting Bay watershed. If you've read my earlier posts about kayaking in Merrymeeting Bay, you might know that Merrymeeting Bay is where the Androscoggin River flows into the Kennebec. FOMB has identified four dams in its threat: the Lockwood Dam in Waterville, "Hydro Kennebec" in Winslow, Shawmut Dam in Fairfield and Weston Dam in Skowhegan.