A replacement for large-scale hydro?
John Waldman and Karin Limburg have just written an article for Yale e360 arguing that large scale hydro has actually damaged the environment and is therefore not the clean energy technology it is often purported to be. For example, on the US East Coast, the authors point out, hydroelectric dams have damaged the ecological integrity of nearly every major river and decimated the runs of migratory fish. They go on to suggest that rivers can be liberated from concrete monstrosities while continuing to produce electricity and that this can be achieved through a variety of factors, including the retirement of many dams as they age, embracing large-scale renewable energy sources and increasing recognition of the failure of traditional engineering approaches to sustain migratory fish populations.
When the waters recede, upon the removal of a dam, the water will go back to being a river and thus occupy only a small part of the space occupied by the waters blocked by the dam. This in turn, Waldman and Limburg suggest, will free up land which could then be used for utility-scale solar and wind power projects. This in turn will maintain the ability of the site to generate renewable electricity while simultaneously resurrecting the fish runs.
Dam removal in the US can be achieved through the FERC relicensing process and through federal and state action. In circumstances where this process has been carried out, it has helped to increase biological diversity through the enhancement of spawning grounds or other habitats. In autumn 2014, excavation machines dredged the last chunks of concrete from the Elwha River in western Washington State where previously two hydroelectric projects had blocked the channel. This was the largest dam-removal project in history. It enabled fish to rediscover spawning habitats that hadn’t seen any fish spawning for at least 100 years, particularly the threatened bull trout and chinook salmon. This gives hope to those who want to see many of the other dams in the US removed (currently numbering as many as 80,000). So far, only 50 rivers have been undammed, most of them smaller hydro projects.
Undamming rivers also has a beneficial effect with regard to the tourist industry. If a river returns to its wild state, it can then be used by kayakers, rafters, hikers and anglers. However, the point Waldman and Limburg are making is that removal of a dam needn’t mean the end of renewable power production on that site.
Or in other words, with just a little bit of imagination, everybody wins, all round – including the power company and its customers.