Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Why is hydroelectricity unfashionable?

spectrum.ieee.org

Post reply on HN
Print view View original

151–160 of 397 posts

Re: Why is hydroelectricity unfashionable?

#151

Post by WJW »

cwkoss wrote: post #136
philipkglass wrote: post #118

Earlier quoted context omitted.

The only other contender that is even worth mentioning is compressed gas, but it seems to have neither the capacity nor the efficiency of a large hydro deployment. The largest pumped storage station in the US has a storage capacity of 24,000 MWh: https://en.wikipedia.org/wiki/Bath_County_Pumped_Storage_Sta... There's an underground hydrogen storage project underway in Delta, Utah with a capacity of 300,000 MWh: https…

How does the energy in underground hydrogen get utilized? Is the capacity the combustive energy, or only the energy from the gas pressure?

No it's mostly the chemical energy in the stored hydrogen, pressure is only a small part of it (though they might insert some expander turbine somewhere in there). Pretty similar to how you'd rate a natural gas storage facility.

Re: Why is hydroelectricity unfashionable?

#152

Post by kagakuninja »

jhoechtl wrote: post #101
onepointsixC wrote: post #17

Hydro isn't unfashionable. We just don't have reasonable places to keep daming, so there's little really to talk about. Nuclear is unfashionable, because there's huge growth potential among wealthy industrial countries, but because it's not "liked" there's very little actual growth.

Nuclear fell out of fashion because people do not understand statics and were unable to address peoples concern about their safety.

Conveniently ignoring the extreme cost of nuclear power. The power companies simply do not want to invest billions and then wait 7+ years, assuming there are no project delays or cost overruns (which there always are). Renewables and natural gas are much cheaper.

Re: Why is hydroelectricity unfashionable?

#153

Post by fastaguy88 »

jjk166 wrote: post #107
idiotsecant wrote: post #60

Earlier quoted context omitted.

Entirely wrong. All pumped storage requires is a big high spot and a big low spot*. Take a look at this, for example: https://www.gordonbuttepumpedstorage.com/ There are a lot of good pumped storage sites out there. *exaggeration, but close enough.

It is ridiculously uneconomical to create the volume for pumped storage. For context, with 100 meters of pressure head, you'd need 25,000 olympic swimming pools worth of water to store 12 hours of electricity from a 1 GW electric plant with 70% roundtrip efficiency. At a cost of $216/cubic yard of excavation, that's over $17 Billion. If you can make 3 cents per kwh profit buying at low times and selling at high, it w…

I am curious where the 216/yd cost comes from. I had a rock driveway put in at 10/yd, and I assume the stone was excavated from somewhere.

Re: Why is hydroelectricity unfashionable?

#154

Post by enaaem »

rocmcd wrote: post #87
idiotsecant wrote: post #60

Earlier quoted context omitted.

Entirely wrong. All pumped storage requires is a big high spot and a big low spot*. Take a look at this, for example: https://www.gordonbuttepumpedstorage.com/ There are a lot of good pumped storage sites out there. *exaggeration, but close enough.

> All pumped storage requires is a big high spot and a big low spot I think that's what the GP meant by "extremely geographically dependent." Finding a 1,000 ft height difference (using the Gordon Butte Project as an example) between reservoirs will be really challenging in huge swaths of the United States and elsewhere.

It also needs to be near a natural source of water, near population centres and is preferably not a pretty national park.

Re: Why is hydroelectricity unfashionable?

#155

Post by chewbacha »

I was hoping that the author would address the environmental concerns. But instead, they are mentioned and then dismissed without argument. The enumerations are many that are mentioned:

   They are blamed for displacing populations, disrupting the flow of sediments and the migration of fish, destroying natural habitat and biodiversity, degrading water quality, and for the decay of submerged vegetation and the consequent release of methane, a greenhouse gas.
Yes, these all happen and are bad for the environment. Why should we still consider it to be green?

Re: Why is hydroelectricity unfashionable?

#156

Post by WJW »

didgetmaster wrote: post #147
tialaramex wrote: post #124

Earlier quoted context omitted.

> I understand that hydroelectricity is used to supply the basic power need, say 80% and a water reservoir with turbines to cover power peak needs This seems like you either didn't understand what pumped storage is, or you've confused several related technologies. A typical pumped storage scheme goes like this: We find a mountain with a high lake and a low lake. We dam the high lake so that its natural outflow (perha…

Do you know the efficiency of using pumped storage? In other words, for every MW of electricity used to pump the water up the hill, how much do you get back in power generation when the water flows back down through a turbine? You will lose a bit of water to evaporation during this process, but it should be fairly negligible. Also all reservoirs lose some water by leakage into the ground. How does the efficiency comp…

Batteries can get up to 95%+ efficiency, pumped hydro up to 85% efficiency so batteries win out in pure energy efficiency. However, when you take into account the economic efficiency then pumped hydro usually comes out very favorable. Battery prices have been falling rapidly over the last few decades, but simply damming up a mid-sized valley can store such a ginormous amount of water that is it hard to compete.

Re: Why is hydroelectricity unfashionable?

#157

Post by agumonkey »

idiotsecant wrote: post #37

Obviously hydroelectricity is massively damaging to ecosystems. My day job includes designing hydroelectric control systems and even I can admit that. That's a big part of the reason that hydro is a non-starter in much of the western world, which is probably a reasonably good thing (although there are certainly some exceptions where hydro development seems like a no-brainer to me but I digress) What's not so clear to…

what about artificial hydro ? make a big large raised water retention thing with generators.. it will take space but not harm existing natural spaces. Even in europe there's a lot of unused land.

Re: Why is hydroelectricity unfashionable?

#158

Post by roamerz »

brookst wrote: post #132
roamerz wrote: post #122

Earlier quoted context omitted.

That ship has already sailed as most power producing dams have been around for long time. Removing them would destroy the (now natural) ecosystem they have created. Plus dams have way more benefits to us than the extremely clean energy they produce - not just store.

This is the first time I've seen a claim that dams create ecosystems that we should worry about destroying. As far as I know, they disrupt fish and animal migrations, reduce natural carbon sinks, reduce biodiversity, and block sediment from providing nutrients downstream. Is there any source saying dams create healthy natural ecosystems? A necessary evil I can kind of see, but a net positive for ecosystems? That seem…

Yup my opinion only. To me water is life and if you let it flow to the ocean where it’s only use is to dilute saltwater you’ve wasted a precious natural resource.

Re: Why is hydroelectricity unfashionable?

#159

Post by BurningFrog »

sidewndr46 wrote: post #126
BurningFrog wrote: post #111

Earlier quoted context omitted.

I think the idea is to start pumping up water at existing hydroelectric power plants. If you do this using wind or solar power the dam becomes a giant battery you charge.

Where does this extra water come from?

Hydro power work by water flowing down turbines from a higher body of water to a lower.

So you can typically pump the lower water back up, using wind or solar power.

Re: Why is hydroelectricity unfashionable?

#160

Post by mnw21cam »

enaaem wrote: post #154
rocmcd wrote: post #87

Earlier quoted context omitted.

> All pumped storage requires is a big high spot and a big low spot I think that's what the GP meant by "extremely geographically dependent." Finding a 1,000 ft height difference (using the Gordon Butte Project as an example) between reservoirs will be really challenging in huge swaths of the United States and elsewhere.

It also needs to be near a natural source of water, near population centres and is preferably not a pretty national park.

Dinorwig power station [0] is in the middle of a national park. A pretty one, even.

[0] https://en.wikipedia.org/wiki/Dinorwig_Power_Station

Post reply on HN