Why Europe is dismantling its dams(bbc.com)
bbc.com
Why Europe is dismantling its dams
https://www.bbc.com/future/article/20240229-why-europe-is-removing-its-dams
52 comments
Ironically and historically it has been mostly the Green party which was against building new dams, as they disturb natural ecosystems.
The Australian Greens (one of the earliest Green parties) were founded basically off the back of opposition to dams in Tasmania: https://en.wikipedia.org/wiki/Franklin_Dam_controversy
Why on Earth is this submission flagged?
A dam is many things; is it for generating electricity? Is it political or ideological? Does it give a geographical advantage? Is it extortionate? Is it for drinking water? Is it beavers? This thing doesn't explain what it thinks a dam is.
I think dams are also used to control the water flow and prevent floods, how to solve that instead?
Can't speak for the ones in this article but they're doing similar in the pacific northwest and many of the dams where built to locally control flooding, but other newer dams further upstream ended up handling the flood prevention better over what were previously multiple dams so there's lots of old dams that have effectively sat unused & blocking fish & wildlife on the river while also providing no benefit.
It's a give and take. Historically, the danger from flooding actually increased because the floodplains next to the riverside were mostly eliminated. They would provide flexibility for the river to meander and to expand in times of heavy rain and would have to be restored as part of a dam removal. They also provide biodiversity and help keep the river water clean.
Dams are also a hazard when there is a lot of rain because you eventually have to open it or risk failure. As the dam gets older it tends to silt up and its integrity becomes less trustworthy, even less water fits in. This requires necessitating expensive maintenance to remedy. Getting rid of it might be cheaper in the long run.
Dams are also a hazard when there is a lot of rain because you eventually have to open it or risk failure. As the dam gets older it tends to silt up and its integrity becomes less trustworthy, even less water fits in. This requires necessitating expensive maintenance to remedy. Getting rid of it might be cheaper in the long run.
Every dam is different...but if a dam has a small reservoir capacity (perhaps partly due to lack of maintenance - so what looks like water behind the dam is mostly accumulated silt), a narrow range of control (the water level is not much different between "flood gates fully closed" and "flood gates fully open", local-only manual controls (vs. pushing a button at National Flood Control HQ), and other issues - then it's actually of little use for those.
So, what about pumped storage?
If wildlife is involved these are almost certainly small run-of-the-river dams.
For pumped hydro you need significant elevation differentials, a pretty good vertical, and lakes at both the top and bottom.
Sites suitable for pumped hydro are really not common, and the financial investment and utility means they wouldn't be getting dismantled.
For pumped hydro you need significant elevation differentials, a pretty good vertical, and lakes at both the top and bottom.
Sites suitable for pumped hydro are really not common, and the financial investment and utility means they wouldn't be getting dismantled.
No meaningful height differential. Which is one component increasing energy storage capacity linearly.
Yeah, let's get rid of one of the most effective sources of green energy that works around the clock! The environmental concerns around dams are legitimate, but they need to be balanced against the consequences of how those energy sources will be replaced. There are also mitigation strategies that can be done instead, like the fish ladders that were mentioned in passing, to help mitigate the environmental impact.
Edit: I see climate change isn't even mentioned which is an enormous red flag when talking about hydro power.
Edit: I see climate change isn't even mentioned which is an enormous red flag when talking about hydro power.
According to the article, not that effective:
> Evaluations concluded that their electricity production had become unprofitable for the power plant owners – especially when the costs of maintenance and mandatory environmental protections, such as fish-ladder introductions, were taken into account, Ollikainen says. So the dams were sold and dismantled. [..] Across Europe, many dams are either approaching the end of their operational life, or the costs of their maintenance are outweighing the benefits they provide.
Aside from various other problems mentioned in the article, which really don't seem that easy to work around, and doing so would make them even less cost-efficient. Never mind all of this takes energy so would reduce the efficiency (although I don't know by what amount, but it does need to be factored in).
> Evaluations concluded that their electricity production had become unprofitable for the power plant owners – especially when the costs of maintenance and mandatory environmental protections, such as fish-ladder introductions, were taken into account, Ollikainen says. So the dams were sold and dismantled. [..] Across Europe, many dams are either approaching the end of their operational life, or the costs of their maintenance are outweighing the benefits they provide.
Aside from various other problems mentioned in the article, which really don't seem that easy to work around, and doing so would make them even less cost-efficient. Never mind all of this takes energy so would reduce the efficiency (although I don't know by what amount, but it does need to be factored in).
> So the dams were sold and dismantled.
Sold to who? Who would buy it just to dismantle it?
Sold to who? Who would buy it just to dismantle it?
I'd guess it's often the owner of the dam's surrounding property, or the property surrounding the reservoir. That'd make it easier to make sensible use of the "new" land, after the dam is removed.
Local governments or consortiums. You usually need to own something before you can destroy it. Besides, the government has a vested interest in acting before the dams fail and kill people.
My guess would be "governments"
The buyers of a certain bridge in Brooklyn, clearly.
Were the dams ineffective or is the regulation ineffective?
Neither. Almost all of the dams involved were built before 1920 and before we had powergrids. They were usually originally intended for some local industrial use and put out a (now) negligible amount of power.
They're also at the end of their service life. You can't leave them, they will eventually burst and kill people. Replacing them is useless, they don't do anything useful. The best solution is to remove them, which has the huge added bonus of unclogging the rivers and restoring the ecosystem and fish habitat.
They're also at the end of their service life. You can't leave them, they will eventually burst and kill people. Replacing them is useless, they don't do anything useful. The best solution is to remove them, which has the huge added bonus of unclogging the rivers and restoring the ecosystem and fish habitat.
Also, the dams silt up over time anyways, so unless you dredge them they are not very good at generating power if the river generates enough silt.
Pumped hydro is more promising in this regard; they don't have to be in the river course itself, so do not run into silting issues, or block fish migration, or any of many other negatives. And because they are basically only required to be battery storage in hours, days or weeks rather than a main source of power generation, they can also be much smaller.
Pumped hydro is more promising in this regard; they don't have to be in the river course itself, so do not run into silting issues, or block fish migration, or any of many other negatives. And because they are basically only required to be battery storage in hours, days or weeks rather than a main source of power generation, they can also be much smaller.
> Research now shows that at least 1.2 million instream obstacles block river flows in 36 European countries, with about 68% less than 2m (6.6ft) in height
I think we are talking about those dam, not the big ones.
> "Absolutely nobody is proposing to blow up or remove barriers which are in use," clarifies Garcia de Leaniz, "We are targeting barriers which are obsolete, which are no longer providing any services to society, that have silted up, and pose a flow hazard."
I think we are talking about those dam, not the big ones.
> "Absolutely nobody is proposing to blow up or remove barriers which are in use," clarifies Garcia de Leaniz, "We are targeting barriers which are obsolete, which are no longer providing any services to society, that have silted up, and pose a flow hazard."
I don't think any dams that produce meaningful amount of energy are going to be removed any time soon. These are the ones that used to power mills and like. So we are talking about way under 1MW in power each.
They are removing all the old dams on the Klamath River. Company that ended up owning them considers them a white elephant because the revenue from power isn't enough to pay for needed refurbishment, operating costs, and insurance.
This is the real reason most of these are removed. No one wants a 100+ year old dam that need several million dollars worth of work and the ROI is negative. So they remove them and everyone is happy. Most of the ones that are removed are well past their use by sticker date.
Even according to the owners, the Klamath River dams represent less than 2% of the power generated by that electric company. https://www.opb.org/article/2022/11/18/klamath-river-dam-rem...
I've been meaning to compare the energy produced by those dams to a similar area of solar panels. Square miles of reservoir to similar square miles of solar farm.
The Three Gorges Dam covers 419 sq miles. Produces 100 X 10^12 watt hours a year.
Internet: 1,000 megawatt-hours per year requires, on average, 2.8 acres for the solar panels.
Calc: 2.3 X 10^11 watt-hours per square mile.
100 X 10^12 wh / 2.3 X 10^11 wh/mile2 => 437 square miles.
The Chinese done goofed.
The Three Gorges Dam covers 419 sq miles. Produces 100 X 10^12 watt hours a year.
Internet: 1,000 megawatt-hours per year requires, on average, 2.8 acres for the solar panels.
Calc: 2.3 X 10^11 watt-hours per square mile.
100 X 10^12 wh / 2.3 X 10^11 wh/mile2 => 437 square miles.
The Chinese done goofed.
Three Gorges comes with its own battery setup. They can basically generate electricity on demand from that battery, assuming no drought. You don’t get that with wind or solar without separate battery setup. That battery could even be the three gorges reservoir itself if you can pump water back up (not sure if they have a bottom reservoir for that).
Drought has hit China very hard recently.
The problem is that some amount of water does have to flow through the Three Gorges since it is a major transportation artery and source of drinking water.
The problem is that some amount of water does have to flow through the Three Gorges since it is a major transportation artery and source of drinking water.
Drinking water isn’t a major use case, but water for farming is, south China gets enough rain at least that drought isn’t so common (for now), but definitely not unheard of since it happened in 2022, see: https://www.theguardian.com/world/2022/aug/22/china-drought-...
From that article:
> The Yangtze is the world’s third largest river, providing drinking water to more than 400 million Chinese people, and is the most vital waterway to China’s economy.
> The Yangtze is the world’s third largest river, providing drinking water to more than 400 million Chinese people, and is the most vital waterway to China’s economy.
Forgetting the slight thing that you might want to have electricity at night too...
Grid-level batteries and pumped hydro (which only requires a height differential, not a riverbed) have been a thing for quite a while now.
So where exactly do you find the hundreds of square miles of space to fit pumped hydro to match this scale? Or even tens square miles with thousand meter drop height? And if that was so easy and cheap, why isn't it already build?
Or grid level batteries storing 140 GWh for even intra-day storage...
Or grid level batteries storing 140 GWh for even intra-day storage...
Admittedly pumped hydro can't be scaled up that much. However, the few places that are suitable are very well appreciated and likely won't ever be dismantled like these dams.
For grid-level batteries, absolute space efficiency is not critical, so they allow a wider range of battery types to be used. Prices are rushing down. They are being deployed on such a massive scale that many new gas powerplant projects get cancelled.
For grid-level batteries, absolute space efficiency is not critical, so they allow a wider range of battery types to be used. Prices are rushing down. They are being deployed on such a massive scale that many new gas powerplant projects get cancelled.
Bedtime is 7:30 pm Comrade Ekaros.
I mean, Three Gorges opened in 2012, when solar panels were more expensive and leas efficient; and the Chinese are the primary reason why they are so cheap and efficient today.
Dams are terrible for the environment(generally poison everything with methyl mercury), and in many cases aren't even that green, since they produce a lot of methane (dam water goes down in summer, that area growns plants, fills up in winter, plants then decompose in an anaerobic environment, producing methane). Depending on the size of the lakes this can be a very large area, ie: big hydro dams in Quebec/BC. There's been research to show one hydro dam produces more greenhouse gases than an equivalently sized coal plant in Brazil.
>Dams are terrible for the environment(generally poison everything with methyl mercury)
What? Where does that mercury come from?
What? Where does that mercury come from?
mercury in the soil ends up being converted to methyl mercury. Generally anything forested with large amounts of carbon in the soil tend to be the worse.
It sounds like you're trying to speak for everyone. Clearly there is a balance (money needs to be spent building new generation of some type). But we can work on climate -and- avoiding the extinction of vital fish species by restoring the flows of rivers.
I don't think the systems at large will afford humanity a second chance or "over time" if we fail to act.
Most of these dams are explicitly uneconomical to run with modern safety standards and 50 years of being under-maintained. There's a lot of dams that were built, the original owners eventually figured out they weren't as profitable as planned, and just wanted to abandon it. An abandoned dam is a future "natural" disaster waiting to happen. And most of these dams were built with pretty mediocre standards, and we don't even build these kinds of dams anymore because they have all sorts of ways of failing unexpectedly.
They have to come down because they were privatized gains, socialized losses as usual. Private companies built them, decided they didn't want them anymore, and basically handed communities unmaintained dams and said "deal with this or drown when it fails". Communities generally don't like being saddled with the waste and consequences of a failed or finished private venture.
We in the US had a huge dam boom at one point, turns out most of them were over-optimistic.
They have to come down because they were privatized gains, socialized losses as usual. Private companies built them, decided they didn't want them anymore, and basically handed communities unmaintained dams and said "deal with this or drown when it fails". Communities generally don't like being saddled with the waste and consequences of a failed or finished private venture.
We in the US had a huge dam boom at one point, turns out most of them were over-optimistic.
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Hopefully they replace them with Coal in Germany
Sure, let all that precious untapped potential energy and source of fresh water go to the sea. When the yearly 1000 year dry season comes,… then you can thank your Nestle shares.
Hydro power is so misunderstood.
Hydro power is so misunderstood.
While I broadly agree with you, most of the dam removal projects I see in the US are tiny dams which have little to no potential for use as fresh water sources and generate tiny amounts of electricity.
I'm strongly in favor of replacing the lost capacity with much larger dams though which have the ability to hold non-trivial amounts of water and have the ability to generate significant amounts of power.
Relatively speaking, the ecological impacts are disproportionately large for what we gain with smaller dams.
I'm strongly in favor of replacing the lost capacity with much larger dams though which have the ability to hold non-trivial amounts of water and have the ability to generate significant amounts of power.
Relatively speaking, the ecological impacts are disproportionately large for what we gain with smaller dams.
I actually wouldn't consider dams very good for climate change resilience either. They get affected by drought, which is increasing due to climate change.
https://www.americanrivers.org/2024/02/saying-adios-to-80-da...:
“As many have heard by now, 2023 was a major milestone year for dam removal in the U.S., with the initiation of the largest dam removal project in the country on the Klamath River in California. However, you may not have heard about the 79 other dams that were removed, reconnecting 1,160 upstream river miles. These projects reestablished migration corridors, made natural and human communities more resilient to climate change, improved access to habitat to promote biodiversity, eliminated safety hazards and maintenance costs, enhanced access to rivers for local communities, reestablished natural processes for healthy rivers, and many other benefits.”