CARLY CASSELLA
31 AUG 2019
If all the hydro-power dams in the United States were removed and replaced with solar panels, it would take up a fraction of the land and produce substantially more electricity, according to a new analysis.
The idea is ambitious, and for now, it’s really just a thought experiment. Today, hydropower is a significant source of renewable energy in the US, accounting for roughly six percent of the country’s total electricity output.
Removing all 2,603 hydro dams in America would leave a huge energy void behind, but it could also provide room for greener opportunities.
While it’s true that hydropower dams are a renewable source of energy, they still produce large amounts of greenhouse gases and can be environmentally destructive and costly to maintain in the long term.
In recent years, these criticisms have led to a growing dam removal movement. And although it’s theoretical, a massive investment in solar power might be able to cushion that loss.
To cover for all the hydro dams currently in use, scientists estimate we would need nearly 530,000 hectares of photovoltaics (PV). While this sounds like a lot, it’s a “surprisingly modest” amount compared to the combined size of most reservoirs, which cover nearly 4 million hectares nationwide.
In fact, the new analysis suggests that substitute solar panels could match the total energy output from hydro dams while using just 13 percent of the same land.
“I think that’s pretty astonishing and tantalising too,” John Waldman, an aquatic conservation biologist from the City University of New York, told Carbon Brief.
“I’m hoping this presents a different mindset for people who think about our energy futures.”
The potential land sitting under reservoirs right now is immense, and if only 50 percent of that surface is drained and used for solar panels, it could greatly improve energy efficiency, producing nearly three-and-a-half times the amount of energy hydropower currently generates.
Even in a more conservative hypothetical, where only a quarter of that drained land is used for solar farms, Waldman and his colleagues calculate energy production could increase 1.7 fold.
In some states, this has the potential to free up huge swathes of land for other purposes, including wildlife habitat, recreation, and agriculture. In Florida, for instance, scientists calculated a solar farm the size of New York’s Central Park (341 hectares) could replace 26,520 hectares of the state’s hydro dams.
The new analysis focused on solar power because it is easily scalable, but the authors argue the same logic can also be applied to wind power on a reservoir’s surrounding ridges and hydrokinetic turbines in a newly-flowing river.
“Also, potentially expensive and difficult-to-permit electrical lines that transmitted the hydropower already exist at these locations and could potentially be repurposed to carry electricity from alternative sources,” the authors argue.
Published findings in Nature Sustainability here.
HT/ozspeaksup
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Many hydroelectric dams’ first function is in flood control. So, go ahead and remove the dams, cover the land now occupied by impounded water with a vast array of solar panels; then wait for the first floods to wash them downstream.
My though exactly. Yep it really make sense to put solar panels on a floodplain. We have far to many educated idiots in this country.
Ummmm! maybe if they glue the panels to the ground and to each other using Extinction Rebellion supporters as caulking?
Probably wouldn’t work but might make the ER lot feel useful.
Seems a few nuclear plants would provide reliable energy with much less land. They don’t wink out at night as do solar panels. Need I mention that water flows at night also?
But, if they insist: Why not just cover a portion of the water with solar panels? Makes more sense than making a road out of them. That’s been tried.
Consider too, the loss of flood control and the lost recreational activities relating to boating, fishing, swimming, and so on.
“… and hydrokinetic turbines in a newly-flowing river”
Are rivers in Florida suitable for such things?
Anyway, a great thought experiment provoked by a non-problem.
Flood control not needed any more?
Dams create more CO2 because they create bodies of water behind them?
https://www.theguardian.com/sustainable-business/2016/nov/06/hydropower-hydroelectricity-methane-clean-climate-change-study
Well it is the Guardian (here we have a local fish wrapper titled The Grunnion Gazette).
Would making the reservoirs behind them less ecologically friendly make them better? How about less useful for boaters and fishermen?
As long as we are abandoning rational ideas, if we could float solar panels on top of these lakes why not suspend them from cables high above the gorges after we demolish the dams?
We must not allow the level of irrationality displayed by these fools to merge into a critical mass of dangerous ignorance.
“We must not allow the level of irrationality displayed by these fools to merge into a critical mass of dangerous ignorance.”
Like has already happened regarding CO2.
Too late
Extinction Rebellion
Irrationality has transformed into dangerous ignorance already
Anyone calculate the lifetime of dams in comparison to the lifetime of solar panels? It’s sad that this wasn’t published on the Babylon Bee or its equivalent.
hoover dam – 1931
lake texhoma dam – 1944
Just two examples – both a little longer than the 20 -25 years for solar panels and windbills
Windbills is an obvious typo but very apropos
This is insane.
No one pays a premium to have a solar-farm side home, or photographs or paints solar-farm scenes.
And how does solar work out with flood control and a reliable source of fresh water?
Labor Day, millions of people head out to the lakes for skiing, swimming, boating, fishing;
but these killjoys really want a prison state that benefits China manufacturing.
We are watching “science” turn in to a dystopian cult.
100% agree.
Great idea! Let’s start with Hoover Dam and see how long it takes Las Vegas to become a ghost town (90% of its drinking water comes from Lake Mead). Severe water rationing in LA will be no problem either.
Kiss a lot of good fishing good bye.
Not to worry: the fish will be sent to re-education camps, where they will learn to live in the woods and be a source of food and sport for fish-hunters.
Yes, it’s just a thought-experiment right now, but…
“I think that’s pretty astonishing and tantalising too,”
Astonishing, yes. Implausible even.
Tantalizing, perhaps because it is always magically impossible and not within reach.
But, I know what crap smells like, and have seen far too many woefully ignorant and incomplete assessments to waste any effort on fantasies and reckless overreaching.
Oh, the abject stupidity of this idiotic ‘proposal’! These intellectual midgets propose to replace reliable, low cost, 100% dispatchable 24/7/365 hydro electrical energy with unreliable, high cost, 25% dispatchable only when the sun shines and is not obscured by clouds photovoltaics. And that’s if the solar panels don’t immolate themselves first. Both Amazon and Walmart have filed suit against Tesla for fires caused by their solar panels. Now, the LA Times reports on the same problem with Tesla residential solar panels installations.
Tesla residential rooftop solar panels catch fire, and the lawsuits start flying
https://www.latimes.com/business/story/2019-08-29/tesla-residential-rooftop-solar-panels-catch-fire-and-the-lawsuits-start-flying
Technically the panels themselves can’t start a fire, but there wouldn’t have been miles of wire up on the roof if not for the panels.
Probably they’ll find the cause was improper installation by the lowest bidder using the cheapest possible materials and paying the lowest wages allowed by law.
No engineers were disturbed by the authors of this idea. Biologists are sciencey folk, too, ya know. How do we know hydro dams actually work at night. Maybe they pack it in at sunset?
If the water itself wasnt a precious resource and if solar panels weren’t fraught with reliability, environmental and service longevity problems, the idea wasn’t that bad. Please don’t do it.
And the only environment that I can think of that would be more risky than floating panels on water, would be floating them on salt water. Rain (slightly acid) will start corroding exposed metal, and waves on the water will slop over the top, make a great importunity for short-circuits.
I suppose these problems could be overcome, but it could only be done at increased cost of materials, construction, and maintenance.
Let’s get “basic” land-based solar panels to a cost-effective, reliable, long-lasting point before we try large floating fields of them.
Some municipalities are forced to cover their water storage ponds to keep light out. (Some kind of chemical reaction with UV) so they use a million black plastic spheres.
Floating solar systems are being built currently, mostly closer to the equator. The panels run cooler and evaporation is less.
Probably a solar PV system could be built that would do the job as well.
Dam life span is a century or more. Solar panel life span is a decade or two at best. Did they figure in the replacement costs?
Aside from the fact that draining existing reservoirs would do next to nothing to create PV capacity – since these reservoirs are not great places to build anything at all – this analysis ignores the fact that nearly all hydropower dams service multiple uses – not just power production, but also flood control, irrigation for cropland, inland navigation, and recreation – none of which is compatible with PV farms.
Silly stuff.
And no, just no – lakes are not big carbon generators. That is preposterous.
Wow! The ignorance of hydrology Cassella is amazing. A large portion of dams with generation were designed with flood control and dry month water retention as their primary purpose. Generators were added to the designs to take advantage of power potential made available by the resultant lakes and design water release rates. An example of this is the Oroville dam north of Sacramento, California. This dam, as well as others up stream, was built to prevent spring flooding of Sacramento. An additional benefit is the water made available for the 6 months of the year when there is little or no rain in California. Of course, adding electric generation to the dam(s) made sense.
Missouri, though having many rivers and streams, has relatively little hydro generation on them. Dams have been built primarily for flood control, with some having generation installed. Those dams such as Truman and Bagnell were installed for power generation but the lakes created are in deep, winding, narrow canyons which are not suitable for solar or wind generation sites.
Oh well, I guess reality doesn’t matter is your paper can garner citations in other documents. Citation count is what makes careers, not accuracy.
Gary Wescom
September 2, 2019 at 11:54 am
Yes, you’re spot on about “citation count”.
Wow, someone actually cited that nonsense? A relative, under duress?
Wot about fish and bath water? When I was in Santa Barbara CA Coupla years ago my host made me stand in a bucket while taking a shower. Relaxed of course since the drought broke and the reservoirs are full. I suppose we can all stand in buckets for ever?
Obviously people with no experience or understanding of electric power generation, transmission and distribution. This idea is a disaster on a massive scale.
I was wondering when this would be talked about. The greenies forget (or chose to ignore) the fact that besides hydroelectric production the reserviors have other benefits too- domestic water source, flood control, recreation. Typical liberals can only think in one plane when it comes to promoting their agenda. Besides eliminating these reservoirs have their own environment problems to contend with.
Great idea, and while we are at it we should drain Lake Michigan and create 22,300 square miles of solar generating space. Upon reading the article I immediately thought of draining lakes Powell and Mead on the Colorado, but their combined area is a measly 498 square miles and a lot of that will be shaded by high canyon walls. And draining lake Michigan would knock out 45 times as much methane generating fresh water environment.
Interesting idea. As it is, I think people are using its water as fast as they can and it’s still at high levels.
This year was supposedly the highest level since they’ve been keeping records. I visited two cities where the parking lots at the beach were partially submerged and you had to swim to the dock to get to your boat.
What did the fish say when it hit a wall? Dam.
The ad at the top of the page is:
I think such an ad would have a much better chance of success on realclimate.org. They’re wasting their money here.
The reservoirs behind the dams do harbor wildlife. The water is often used for more purposes than just generating electricity. There is still plenty of places to construct solar panels like on roof tops and over roadways and parking lots. Solar panels do not provide electricity at night and on cloudy days but hydroelectric facilities still do. Solar facilities and wind farms might be used to pump water back in to lakes during the day instead of having to use batteries at night. In terms of land use. nuclear power plants require a lot fewer acres per Kilowatt hour than does hydroelectric or solar. Nuclear is actually better for the environment.
So we need a lake at the bottom of the dam too.
Won’t that make twice as much methane and take two dams?
All i can say about this is that they should put the Bong down and slowly walk away…
Aaaaand what do we do for the drinking water also stored in the hydro dams ?
That is easy. Every morning the good citizens will form up in neat lines just before dawn and take turns to lick the moisture that has formed off of the solar panels.
530,000 hectares of photovoltaics (PV). While this sounds like a lot… It is a lot. It’s 2,070 square miles.
The total 4 million hectares of the reservoirs is 15,625 square miles, on which collective farms could employ some of the now-unused water to raise veggie burgers for the communities of tree-huggers.
The potential land sitting under reservoirs right now is immense, and if only 50 percent of that surface is drained and used for solar panels… I suppose it’s too much to ask the learned ‘study’ authors how they’ll insure that the 50 percent they retain is all on the northerly (south-facing) side of the storage basins, since the southerly sides face away from the sun and will see damn little sunlight. Maybe they’ll tilt the basins first?
Also I don’t see how the ‘current power lines’, which carry hydropower 24/7 from their generators, will be such a success when actually used less than half a day in the real world.
Sunlight is the source of energy for both. Dams are just equivalent to storage batteries. The PV panels they are comparing have no batteries….