Why is hydroelectricity unfashionable? • Hacker News Board

Re: Why is hydroelectricity unfashionable?

#181

Post by google234123 » Thu, Oct 27, 2022, 9:26 PM UTC

kagakuninja wrote: post #152

jhoechtl wrote: post #101

Earlier quoted context omitted.

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.

The extreme cost of nuclear power are partially the fault of scaremongers stopping all production of them in the west. China has 100s being built or planned and obviously they can't cost 10s of billions each.

Thanks for blackouts when it's cloudy and not windy.

Re: Why is hydroelectricity unfashionable?

#182

Post by plorg » Thu, Oct 27, 2022, 9:28 PM UTC

mnw21cam wrote: post #160

enaaem wrote: post #154

Earlier quoted context omitted.

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

Yes, and add you can see it's already been developed - for over 60 years. That's not to say more can't be developed, but the rate of new development has been pretty low, and the prevailing belief was that this was the result of all of the best resources being used up.

Re: Why is hydroelectricity unfashionable?

#183

Post by Gwypaas » Thu, Oct 27, 2022, 9:29 PM UTC

roamerz wrote: post #158

brookst wrote: post #132

Earlier quoted context omitted.

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.

Dams does not save any water except the initial filling. Their inflow and outflow match over a seasonal cycle.

Re: Why is hydroelectricity unfashionable?

#184

Post by heavenlyblue » Thu, Oct 27, 2022, 9:32 PM UTC

BurningFrog wrote: post #159

sidewndr46 wrote: post #126

Earlier quoted context omitted.

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.

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

Re: Why is hydroelectricity unfashionable?

#185

Post by 7952 » Thu, Oct 27, 2022, 9:35 PM UTC

idiotsecant wrote: post #63

bryanlarsen wrote: post #57

Earlier quoted context omitted.

We certainly can use solar, wind & batteries to eliminate fossil fuels from our electricity system. Estimates are that we'd need about 300TWh of batteries, which is on the edge of feasible. Pumped storage would be a lot cheaper, though.

Oh great, only 300TWH of batteries! Let's put in the P.O.! Who is supplying those, again?

Its not like you can easily sign a PO for a pumped storage site either. Large scale civil engineering is still difficult in most places. And surely it requires lots of survey and design work.

With batteries you can design the site, get consents and order battery units off the peg in under a year.

Re: Why is hydroelectricity unfashionable?

#186

Post by 7952 » Thu, Oct 27, 2022, 9:38 PM UTC

throwaway894345 wrote: post #86

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…

My impression as a layperson is that the economic feasibility of pumped hydro is very location-dependent, and our electrical grid isn't so fungible that storage in one region can meaningfully store energy generated in another region. Is my understanding correct? And if so, how do we tackle that?

Pumped hydro is very dependent on location. But the supply of energy would not need to be. Electricity grids and DC interconnectors work really well. Having a few massive sites spread across a continent could work well.

Re: Why is hydroelectricity unfashionable?

#187

Post by tb_technical » Thu, Oct 27, 2022, 9:42 PM UTC

Because of NIMBYs

Re: Why is hydroelectricity unfashionable?

#188

Post by WJW » Thu, Oct 27, 2022, 9:46 PM UTC

ssivark wrote: post #176

WJW wrote: post #156

Earlier quoted context omitted.

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.

I would imagine energy density to be a bigger shortcoming (gravitational acceleration times height difference) -- especially for typically accessible height differences. Eg for 500m this is something like an order of magnitude lower than chemical batteries (which are themselves presumably at least an order of magnitude lower than gasoline). This would mean that we need reservoirs to be much larger than equivalent che…

> This would mean that we need reservoirs to be much larger than equivalent chemical batteries.

Yes we know. It is still cheaper on a cost-per-kwh basis than batteries, by a significant margin.

> I would love to see an analysis of whether it is feasible to build enough such large scale reservoirs (and how many we would need) to store an order one fraction of the daily energy needs. (at city/country/world levels)

No it is not, there are not enough suitable sites in most places in the world to make this work for world levels. That said, it is entirely up in the air if there would be enough mineable lithium to make batteries for similar amounts of storage.

Efficient electrical energy storage at scale is currently unsolved.

Re: Why is hydroelectricity unfashionable?

#189

Post by kennend3 » Thu, Oct 27, 2022, 9:47 PM UTC

cinntaile wrote: post #69

pclmulqdq wrote: post #65

Earlier quoted context omitted.

Wind and solar energy also destroy ecosystems, but we don't stop using them. Dams may be more harmful, though.

What's your definition of destroy and do you have any examples of ecosystems that were destroyed by wind and solar?

At the end of the day, the real issue is "NIMBY".

Solar - sure we will protest that:

https://barrie.ctvnews.ca/solar-project-demonstration-in-tay...

Wind - yep... people will protest that:

https://toronto.ctvnews.ca/ontario-wind-power-opponents-prot...

Nuclear? Of course:

https://globalnews.ca/news/4298298/protesters-rally-pickerin...

So.. when those people go home, what do they think powers the lights?

Re: Why is hydroelectricity unfashionable?

#190

Post by Kubuxu » Thu, Oct 27, 2022, 9:48 PM UTC

fastaguy88 wrote: post #153

jjk166 wrote: post #107

Earlier quoted context omitted.

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.

Usually the rock is waste from excavation. When buying it you pay the cost of transport, group that did the excavation might have even paid for the rock to be removed.