Hydropower, using dams and waterfalls to generate electricity was a major development in the 20th century. It takes energy directly from nature in a sustainable way but doesn’t have all of the negative impacts like pollution that traditional forms of generation have. But we’ve maxed out on hydro. So what’s the next all natural energy source that’s right for the 21st century?
I was in a conversation the other day when the topic of hydro-power came up. Under different circumstances, I’d be all over hydro like a cheap suit — in a good way, that is. What’s not to like about hydro? The discussion was over how to make more renewable power couldn’t we make more dams? Unfortunately, a good thing, like hydro, is not an infinite resource.
Hydropower is a good idea except that in many areas rivers are already dammed, so the prospect of creating more hydropower is remote. Hydro contributed 16.6 percent of the world’s total electricity and 70 percent of all renewable electricity in 2015. But in 2018 wind generated power surpassed hydropower in the amount generated for the first time according to the New York Times.
In 2015 hydropower contributed 25 percent of all power from alternatives in the US, however, alternatives only comprised 10 percent of all energy consumed. While it’s used extensively in the US, it’s difficult to suggest where we’d place more dams — that’s hydro’s first disqualifier and there are a couple more.
Take the major hydroelectric projects on the Colorado and Columbia rivers, for example. There are 60 dams in the Columbia River watershed and more than 45 in the Colorado River Basin. These dam systems provide significant hydroelectric power and fresh water to the northwest and southwest and without them these areas could not support the number of people living there.
But while the western river system is well dammed, global warming has reduced rain and snowfall, placing less water behind big dams and making them less effective for generating electricity.
Also, river ecology is on the front burner in many places, providing strong headwinds to hydropower expansion and some localities have begun destroying their dams and returning rivers to their wild states.
More to the point, hydroelectric generators are also among the country’s oldest power plants and they have working lives. Recent reporting suggests that America’s dams are, like much of its infrastructure, in poor condition. A New York Times article notes that the U.S. Army Corps of Engineers keeps an inventory of 90,000 dams across the country and that 70 percent of these dams will be more than 50 years old by 2020. Almost 2,000 state-regulated, high-hazard dams in the US were listed as being in need of repair in 2015.
The Association of State Dam Safety Officials estimates that repairing all the dams would cost $60 billion. That’s a lot of money but cheap for what they represent which is a lot of power and water to support life in the northwest and southwest US.
Geothermal for the 21st century
The more I thought about it though, the more I realized that Enhanced Geothermal Systems or EGS might be the hydro-power of the 21stcentury, at least metaphorically. Think about it. Both approaches directly harness a significant natural energy source to produce clean, renewable electricity.
Hydro-power funnels high-pressure water through turbines that drive generators. EGS captures heat from earth’s crust through steam which is used to turn a different kind of turbine but the result is the same: alternating current. Better yet, there’s a great deal more energy available as heat than there is coming from dam projects.
In a way EGS is the natural successor to hydro-power for entities looking for a renewable source of clean base load power. Other power solutions like solar and wind don’t provide base load power because they cease when the sun goes down or if there isn’t enough wind. But hydro and EGS don’t have that problem which makes them very valuable. In one report the Department of Energy estimated there is one thousand times the amount of energy we need on an annual basis sitting under the Rocky Mountains.
Geothermal isn’t complicated. The center of the earth is molten rock and very hot, it’s kept that way due to radioactive materials that have been there since the earth formed about 4.6 billion years ago. The center is 4000 miles away but still heat reaches the crust from that distance. Geothermal taps into that heat and brings it to the surface as superheated steam. That’s what drives power generators. Think of earth as a natural nuclear reactor but without all of the overhead of refining and containing radioactive materials. It’s a cool trick and an incredible bit of natural engineering.
So the point of geothermal is that there’s a huge source of energy available to us for free. We just need to drill some holes in the earth, something we perfected in the oil business.
If you think that electricity only comes from hydro, solar, wind, nuclear, or burning fuels, there’s good news. You don’t have to mess with lethal radiation, solar or wind to be productive with renewables. The more you look at EGS, the more there is to like.