In my last post I discussed the renewable energy grid in the United States. Renewables make up 11%. I discussed wind, solar, and geothermal and substantive contributors to that 11% figure, but I noticeably did not delve into hydro electric which makes up 22% of renewable energy in the U.S. I believe that much like nuclear; hydroelectricity has its controversies and deserves a deeper conversation to truly weigh all the nuances. Hydroelectricity in the context of this post will cover dams and their use in the U.S. I am not referring to tidal current turbines when I refer to hydroelectricity.
Let us start with the usual and have a quick ELI5 of hydroelectricity. We have covered turbines so many times in this blog that it seems redundant to do so again, but here we are. Much like wind, geothermal, and even fossil fuel plants, hydroelectricity is harnessed by the turning of turbines. Though, in this case the water is simply allowed to flow through a penstock and turn the turbines. Heating the water inro steam to rotate turbines is not necessary. As far as the prevalence of hydroelectricity is concerned, just about 50% of its capacity is in California, Washington, and Oregon, and the top producing state in the country is Washington as hydroelectricity relies heavily on consistent precipitation.
Now if you are reading my blog, chances are that you have seen the movie DamNation which chronicles the problems with hydroelectricity. If not, the movie stresses cultural impacts that dams have had on native peoples in the U.S. Additionally, dams cause harm to the ecosystem by disrupting the breeding patterns of wildlife, such as salmon which instinctively try to swim up streams that have been dammed off. Dams also have an impact on the water quality by both creating pools of “hot” stagnant water and by releasing oxygen deprived water into the local rivers which puts additional stress on wildlife.
At this point, hydroelectricity makes up about 6.6% of the U.S. energy grid, a percentage that has been decreasing since the 1950s, but has stagnated since the early 2000s. Though I believe that with the rise of other renewables and the decrease in the price per kilowatt hour produced by those methods, I am hopeful that we can commit to the final push away from hydroelectricity. Unfortunately, hydroelectricity is not the only driving factor when it comes to dams. In fact, it is not the main factor at all as only 3% of dams in the U.S. are electricity producing. The majority of dams in the U.S. were constructed for irrigation and water management purposes. As we move away from hydroelectricity in this country, it is also important that we find new ways of managing our water to sustain our agribusiness to be able to cohabitate with the environment and native species around us.
If you would like to discuss dams further or have a differing opinion, please leave a comment below.