14 ms·
Answering in one go the comments of yread and rapsey. The dams are all really old (50's and 60's) with low power output (about 20MW). Maintaining them costs a
by Loic 4y ago
Answering in one go the comments of yread and rapsey.
The dams are all really old (50's and 60's) with low power output (about 20MW). Maintaining them costs a lot and I suppose that if the owners agreed and partially funded the demolition is that it was cheaper to do it than to maintain the dams.
It means that if you look at the limited scope of the involved parties: "nature, salmons, energy production and maintenance" this is the best path forward and a win-win situation.
Of course we lose "reliable" power production, but because of the limited power production of these old dams, I for once agree with the ability to replace them with other forms of renewable energy + storage.
- hannob 4y ago> The dams are all really old (50's and 60's) with low power output (about 20MW). This obviously raises the question of how much power output they could produce if you'd convert them to modern technology.
- Gare 4y agoNot much more, I'd presume. Hydrology is the limiting factor.
- nopenopenopeno 4y agolike nuclear
- londons_explore 4y agoThey couldn't produce more energy in a year, since that is limited by the rainfall and dam height. But with a redesign/upgrade, they could probably produce more power at peak times. That allows the dam to be used like a peaker plant, earning far more per MWh than a coal plant. As more wind and solar is deployed, the difference between the peak and average energy prices will only increase.
- Steltek 4y agoI could be wrong but I don't think hydro has a low enough spin-up time to be useful as a peaker plant.
- toomuchtodo 4y agoHydro ramp is very quick, only limited by the delay in mechanical inertia of the turbine and generator rotors. Most dams can be at peak output in ~10 seconds. With that said, these particular generators can be replaced with renewables and batteries trivially (and the costs are even more reasonable with the recent passing of the inflation reduction act) due to their smallish capacity (~200 acres of land for 20MW solar, small footprint for the storage system).
- BurningFrog 4y ago> these particular generators can be replaced with renewables and batteries trivially Renewables and batteries can be added trivially. I don't see how that means the dams should be torn down.
- toomuchtodo 4y agoBecause they’re detrimental to the biome in this case. Every evaluation will be different, each with nuance. EDIT: I think, importantly, that these decisions should require the replacement of generation capacity lost with clean generation and storage as part of the cost benefit analysis.
- bobthepanda 4y agoThat may not even be necessary. This demolition happened in Oregon. Despite a growing population and increasingly hot summers, Oregon’s electricity use peaked in 2000. https://www.oregon.gov/energy/energy-oregon/Pages/How-Oregon-Uses-Energy.aspx https://www.oregon.gov/energy/energy-oregon/Pages/How-Oregon... US energy demand has been plateauing for a while as well: https://www.eia.gov/todayinenergy/detail.php?id=38572 https://www.eia.gov/todayinenergy/detail.php?id=38572
- kube-system 4y ago> They couldn't produce more energy in a year, since that is limited by the rainfall and dam height. Design also dictates the minimum water height that can be used to produce power, so a redesign could actually give a wider range of water heights at which power generation is possible. And turbine efficiency has improved over the years, so you can generate more energy with the same water.
- indymike 4y ago> This obviously raises the question of how much power output they could produce if you'd convert them to modern technology. Maybe 10-15%. AC generation technology has improved incrementally (1% here, 4% there), but gains since the 60s are not revolutionary leaps.
- mullen 4y agoThe problem is not the tech that is in the hydro-generators but the dams, themselves, silt up. They hold a lot less water and thus, less energy to drive hydro-generators. To restore a silted up dam, you would have to clean it out, which is a whole nother environmental issue in itself.
- jl6 4y agoFor comparison, a single GE Haliade-X wind turbine can output 14MW at peak.
- yread 4y agoAnd can you switch it on when you need to cover the peak of electricity consumption like with a dam? No. You need a gas turbine.
- onion2k 4y agoYou need a gas turbine. Or a battery.
- subradios 4y agoNope. Most buffering in the US as deployed is natgas, not poison the water lithium.
- SketchySeaBeast 4y agoIsn't it a choice of "poison the water" or poison the air? Are we under the assumption that natural gas is clean?
- subradios 4y agoI was sardonically calling out that a lot of the energy picture is much more complicated than that. The battery production process (and PV production process) is quite ecologically intensive, and large portions of the reduction in prices we've seen has been by manufacturing in places that don't exactly have high standards for these things.
- rob74 4y agoOr a (pumped-storage) hydroelectric plant, to take the discussion back (almost) full circle.
- concordDance 4y agoElevated water is very good energy storage. I suspect they have no viable energy storage plan to replace it.
- deleted 4y ago[deleted]
- tohnjitor 4y agoWhy the scare quotes around reliable? Hydroelectric generation is reliable. So reliable that New York State generates approximately 70% of its electricity from hydro. Fashionably, the state government is planning to replace every hydro plant with wind or solar over the next 20 years.
- alex_duf 4y agoI'm assuming in this context OP made a reference to how solar + wind + battery is often seen as unreliable (intermittent). So by opposition hydro would be reliable. but describing renewables like wind and solar is missing the whole picture. Now I might be completely off track and putting words in the mouth of OP without any proof. Just a hunch.
- onion2k 4y agoHydroelectric generation is reliable. Even when the dam is 70 years old?
- deleted 4y ago[deleted]
- twiddling 4y agoSilt Happens
- greendave 4y agoHydro _can_ be reliable. But out in the drought-prone west it has not been especially so. California generated 33GWh from large hydro in 2019 (14.6% of total production) vs. 15Gwh (7.5%) of total production in 2021. 2022 will likely be worse.
- elihu 4y agoHoover dam kind of gets hit twice; not only is there less water moving through the system, but they've let the water levels drop to the point where the energy they could get by running, say, three gallons of water through the system now requires them to use four gallons because the altitude difference is less. (I don't know what the exact numbers are.)
- jasonwatkinspdx 4y agoOne of my friends used to work for the state of Oregon as an economist doing analysis related to these dam demolitions. They are a good thing for the environment, full stop. The loss of hydro with these smaller damns is not material. Their impact on hundreds of miles of habitat is. And for those who only want to think in terms of material wealth, there's real money in restoring salmon populations. So please don't do the hackernews reflexive contrarian thing and be all "well look at those idiots don't they see we need every bit of green hydro power that exists?" because the real analysis being doing is years worth of sophisticated measurement and modeling. You haven't somehow outsmarted that with your off the cuff observation. Edit: I guess I can mention a bit more without too much risk to my friend's privacy. During the years he was working as a part of this we were on vacation together at one point, and we ended up pairing on some problems he was having getting his R model working with ArcGIS. The task he was working on was modeling the changes in large herbivore populations that would result from various changes to the rivers. There are tons of these downstream effects that depend on the river. Losing the power generation is just one concern among 100s. So yeah, they thought very deeply about the implications and tradeoffs here.
- dsfyu404ed 4y ago>So please don't do the hackernews reflexive contrarian thing and be all "well look at those idiots don't they see we need every bit of green hydro power that exists?" because the real analysis being doing is years worth of sophisticated measurement and modeling. You haven't somehow outsmarted that with your off the cuff observation. You can't fight religion with logical analysis.
- steve_adams_86 4y agoI’ve been making this case here in BC since the BC Hydro company began pushing hard for a new large dam in Northern BC. It’s remarkable how well hydro was greenwashed. People think I’m an idiot when I saw we should generate power another way. They’re incredulous. How could a dam even cause environmental damage? It’s such a limited scope. We have ways of allowing fish to spawn past the dam. No big deal. Here we have environmentalists who are pro hydro and anti-nuclear. It’s surreal.
- jollyllama 4y agoSounds good, where's the plan to replace the capacity?