Large dams are unpopular with environmentalists
By Ed Burke, Dennis K. Burke Inc.
Hydropower is the nation’s most affordable, reliable, and sustainable energy source, accounting for about half of all renewable energy generation in the U.S. Unfortunately hydropower does come with some environmental baggage.
The granddaddy of renewable energy, hydropower has over 100 years of history in the U.S. Relying only on the power of moving water, hydro produces clean energy with zero carbon. Other renewables also benefit from hydropower, which can quickly increase or decrease output to keep the electric grid in balance when “intermittent” renewables like wind and solar are not generating electricity.
Today, hydropower generates about seven percent of the U.S. electric supply, with the largest hydropower producers in Washington, California and Oregon.
Electric operators in New England have been importing more and more hydroelectric generation from Quebec over the past decade. Natural gas and hydroelectric are displacing the use of coal and oil as generation fuels in New England.
The President’s Climate Action Plan notes that hydropower is essential to meeting the country’s renewable energy targets. There are more than 80,000 dams across the U.S., and only about three percent of them are used to generate electricity. The administration sees this as an opportunity to encourage hydropower development at existing dams and retrofit existing non-powered dams.
Renewable Or Not?
Most federal agencies recognize hydropower as a renewable energy, and are working with industry to resolve hydro’s environmental shortfalls.
But most states don’t include all hydropower produced in their renewable portfolio standards (RPS) that require utilities to generate a percentage of their power from renewable sources. Environmental impact, restrictions on new construction, and limiting the size of hydro plants are just some of the factors that help shape state policies on what qualifies as renewables.
In general, large hydropower facilities are not counted toward the state’s renewable energy goals. Most environmentalists agree that including large-scale hydro as a renewable would discourage development of new renewable sources, like wind and solar. Conservation groups say that the reluctance to call hydropower a renewable energy is largely based on the impact of dams on fisheries and water flows.
Large dams block migrating fish from reaching their spawning grounds. Additionally, silt and sediment build up, and water temperatures change, which affects the ecosystems and wildlife along the river or stream. Over the years, these factors account for drastic reductions in fish populations, and prevent important sediments from reaching estuaries.
According to the Sierra Club website, hydropower produces no air pollution or global-warming pollution, but the environmental effects of damming rivers can be severe. The Sierra Club supports small-scale hydropower and the use of existing generating plants, but because of the effects of large dams on wildlife and watersheds, the Club does not support large-scale hydropower.
Others argue that it is better operations—and not dam size—that matters, using a recent project on the Penobscot River in Maine as a good example of balancing size and operation. The Penobscot River Restoration project reversed more than two centuries of environmental damage on the Penobscot River. Removal of the lower two dams and bypassing of a third greatly improves access to nearly 1,000 miles of habitat for endangered Atlantic salmon and shortnose sturgeon, American shad, alewife, and seven other species of sea-run fish in Maine. As fish passage is improved at four remaining dams and energy increased at six, these ecological benefits will be realized while maintaining or even increasing energy production. By reconnecting the river to the sea, the Penobscot Project promises large-scale ecological, cultural, recreational and economic benefits throughout New England’s second largest watershed.
No More Dams
One thing everyone agrees on is that we don’t need any more dams.
Dam removal may be playing a major role in river restoration projects across the country, but not everyone agrees with the idea. Some dams are vital components of the water infrastructure, and they play a pivotal role in water storage, irrigation and flood control. At a time when much of the West is facing a possible 100-year drought, removing these dams could have a devastating impact.
In Washington, an amendment was attached to the House of Representatives’ 2016 Energy and Water Appropriations bill that would support water storage projects by preventing any funding from being used to remove any federally owned or operated dams. The Senate must now write and pass an appropriations bill.
So can these environmental issues be resolved? Our ability to mitigate damages has improved over the years. For example, fish ladders and fish passages allow fish to make their way upstream past the dams.
Looking ahead, small-scale turbines are seen as the biggest and most important growing component within hydropower. In-stream turbines that are now being developed will generate hydropower with a very small environmental footprint.
So, how affordable will the next generation of hydroelectric be, and will hydro be able to compete with wind and other renewables? For the industry, how will state regulations and policies influence renewable energy investment dollars? The answers to these questions will help decide hydropower’s place in the future energy mix.