Why is hydroelectricity unfashionable? • Hacker News Board

Re: Why is hydroelectricity unfashionable?

#261

Post by gwbas1c » Fri, Oct 28, 2022, 4:00 AM UTC

jhoechtl wrote: post #90

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…

Forgive me my lack of understanding of the englisch language, but I do not understand the distinction you make. Hydroelectricity: Is this power you obtain by placing turbines behind a huge concrete wall of a large river? If so, how is the scenario of building a large concrete dam in the mountains where water is pumped up a hill to covert it into kinetic energy any more better? I understand that hydroelectricity is us…

Think of pumped storage like a battery: In areas with a lot of solar, pumped storage runs when there is a lot of daylight to store the energy for nighttime use. Pumps run when the sun is out, turbines run at night.

Re: Why is hydroelectricity unfashionable?

#262

Post by pencilguin » Fri, Oct 28, 2022, 4:15 AM UTC

philipkglass wrote: post #229

ClumsyPilot wrote: post #221

Earlier quoted context omitted.

You are confusing energy storage and fuel storage. I am talking about CAES, it uses electricity to compress air and feed that into a container, like a metal cylinder or caverns lined with impermeable material. When you need electricity, you release the air through a generator and produce electricity. Hydroelectric, compressed air and batteries have round trip efficiency of ~80%. https://www.sciencedirect.com/topics/e…

The facility you linked produces and stores chemical fuel, and can't even convert it back into electricity. The project includes using Mitsubishi M501JAC combined-cycle gas turbines to turn the hydrogen back into electricity: https://www.powermag.com/aces-deltas-giant-utah-salt-cavern-... https://power.mhi.com/products/gasturbines/lineup/m501j This turbine has a rated combined-cycle efficiency of 64%. Production of h…

Industrial-scale electrolysers will soon be well over 90% efficient.

Re: Why is hydroelectricity unfashionable?

#263

Post by pixodaros » Fri, Oct 28, 2022, 4:18 AM UTC

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…

Its also that most of the best sites for hydropower have already been heavily developed. Countries like Egypt, Canada, and Norway have massive amounts of hydro because it was obviously a good deal since the late 19th century. In western Canada, there is a big debate about the Site C dam site which is not just destructive but based on unstable rock.

Re: Why is hydroelectricity unfashionable?

#264

Post by int_19h » Fri, Oct 28, 2022, 4:23 AM UTC

brianwawok wrote: post #254

jjk166 wrote: post #125

Earlier quoted context omitted.

Yep, now we just need to excavate the reservoirs on those high and low spots, a mere 100% of the work required.

This is nonsense. We have lakes already. We don’t dig two giant holes in rock. Look at real work pumped storage costs.

That's the "geographically dependent" part.

Re: Why is hydroelectricity unfashionable?

#265

Post by lvxferre » Fri, Oct 28, 2022, 4:35 AM UTC

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…

It gets worse once we remember that electricity can be transported, but the damage stays mostly in place.

Re: Why is hydroelectricity unfashionable?

#266

Post by seanmcdirmid » Fri, Oct 28, 2022, 4:35 AM UTC

tialaramex wrote: post #124

jhoechtl wrote: post #90

Earlier quoted context omitted.

Forgive me my lack of understanding of the englisch language, but I do not understand the distinction you make. Hydroelectricity: Is this power you obtain by placing turbines behind a huge concrete wall of a large river? If so, how is the scenario of building a large concrete dam in the mountains where water is pumped up a hill to covert it into kinetic energy any more better? I understand that hydroelectricity is us…

> 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…

Pumped storage can also be used with existing hydro stations, just have a reservoir at the bottom to save water that can be pumped back up to the top of the dam. See https://www.nwcouncil.org/sites/default/files/MarkJones_1.pd... for the one at grand coulee.

Re: Why is hydroelectricity unfashionable?

#267

Post by seanmcdirmid » Fri, Oct 28, 2022, 4:42 AM UTC

heavenlyblue wrote: post #184

BurningFrog wrote: post #159

Earlier quoted context omitted.

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.

You need a reservoir to store that water downstream as well, it can't just be a river

Ya, this is how they do it. Eg see https://en.wikipedia.org/wiki/Dry_Falls_Dam

Re: Why is hydroelectricity unfashionable?

#268

Post by pfdietz » Fri, Oct 28, 2022, 4:45 AM UTC

sidewndr46 wrote: post #257

pfdietz wrote: post #253

Earlier quoted context omitted.

There's no river at the bottom, either. I thought the "desert" part would make that clear, but I guess it had to be said. Water in this system is part of the capital cost (charging it up when you start), then a minor maintenance cost (replacing evaporation). Otherwise, unlike primary hydro, there is no large constant flow out of the system, and no need to be on a river. The water lost to evaporation is at least an or…

Wouldn't you need two reservoirs in that case? Otherwise where is the water being drained down to take advantage of the potential energy?

Yes, of course. Off-river pumped hydro involves two reservoirs.

Re: Why is hydroelectricity unfashionable?

#269

Post by seanmcdirmid » Fri, Oct 28, 2022, 4:46 AM UTC

muaytimbo wrote: post #77

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.

It IS unfashionable, dams are actively being removed across the US in order to restore the ecosystems they shattered. Migratory fish and all predators higher up the trophic chain are devastated by any type of dam.

Mostly smaller dams that were built a long time ago. They would need to be replaced anyways, so just tearing them down and not replacing them is economical and ecological.

But the big ones built in the last 100 years are going to stick around for awhile.

Re: Why is hydroelectricity unfashionable?

#270

Post by seanmcdirmid » Fri, Oct 28, 2022, 4:49 AM UTC

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.

Nuclear was simply too expensive for the other side to bother debating with the environmental opposition. Unless the government subsidizes it (construction costs), private companies aren’t going to go near it. Other renewables are simply so much more profitable these days.