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Why is hydroelectricity unfashionable?

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Re: Why is hydroelectricity unfashionable?

#171

Post by Retric »

azylman wrote: post #167
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…

If this still builds a dam, doesn't this have the same environmental concerns as any hydro project? Or is there something that makes this less of a concern?

Ideally you don’t build a dam.

Niagara Falls sits between Lake Erie into Lake Ontario. Which is the perfect location to use pumped hydro because all you need to build is a pipe between them and put a turbine inside the pipe. If you have excess energy pump water up from Lake Ontario to Lake Erie, and when you need power run that in reverse to generate electricity.

Move enough water and the water level on each lake will change, but 6 inches (15cm) isn’t going to change anything of note and that represents an insane amount of energy. Something like 500 GWh if I remember correctly. Unfortunately that’s literally the best case in the US, nothing else even comes close.

Re: Why is hydroelectricity unfashionable?

#172

Post by [deleted] »

ClumsyPilot wrote: post #43
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…

> We need storage and pumped storage is the only practical way to get there with current supply chains and technology. This really cannot be enphasised enough - this is the only game in town. The solutions are needed yesterday, and must be built on a massive scale - there is no time for a 20 year R&D to production cycle of a miracle technology. Only hydro does not require any new minerals and mining. The only other c…

[deleted]

Re: Why is hydroelectricity unfashionable?

#173

Post by _hypx »

ClumsyPilot wrote: post #43
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…

> We need storage and pumped storage is the only practical way to get there with current supply chains and technology. This really cannot be enphasised enough - this is the only game in town. The solutions are needed yesterday, and must be built on a massive scale - there is no time for a 20 year R&D to production cycle of a miracle technology. Only hydro does not require any new minerals and mining. The only other c…

The recent appearance of hydrogen energy storage has basically refuted this argument. We can now store all of the renewable energy we want. The only problem is the lack of awareness among environmentalists and engineers.

Re: Why is hydroelectricity unfashionable?

#174

Post by theptip »

lutorm wrote: post #94
theptip wrote: post #79

Earlier quoted context omitted.

Is this supported by the report though? We have yet to build most of the solar we need, and IIUC almost half of new solar is now being built with storage: > At the close of 2021, there were more than 670 GW of solar plants in the nation’s queues; 285 GW (~42%) of this capacity was proposed as a hybrid, most typically pairing PV with battery storage (PV+storage represented nearly 90% of all hybrid capacity in the queu…

My impression is that most "PV+storage" plants have storage enough to handle uneven loads and production rates on maybe hour timescales during the day. The storage required to provide overnight supply, though, is much larger, not to mention that required to handle seasonal variance in PV production. It seems hard to imagine batteries would provide that, but for that maybe the most cost-effective option is to just siz…

I previously shared your impression but this report seems to suggest otherwise; see p24 in particular:

> • Battery:PV capacity ratio always at 100% in HI; lower on the mainland (but increasing over time—see bottom right graph) • Storage duration ranges from 2-8 hours; 50 of the 61 plants have 4-hour duration (other 11 are 5x2 hr, 1x3.7 hr, 4x5 hr, and 1x8 hr)

And there are some detailed case-studies that give other examples too:

The first one (Pine Grove substation) gives a sort of "emergency button" to provide 12 hours of load relief, when they call it in. This seems like it's basically just shaving off extra load that occurs on particularly busy days (~40/year), it's not solving the core demand-curve mismatch. (It looks like the batteries function as essentially very-short-term demand smoothing/arbitrage when they are not being called in).

The second one (Wheatridge) is 4H of 30MW (~10% of the power of the whole facility); I don't have a feel for whether this is closer to the full demand-curve mismatch.

Edit to add: There's actually another case study that might be even better, Slate PV + storage plant in CA, which is ~50% power for 4 hours, which is very substantial.

I think you're right that you can't store much energy overnight -- but that's not really required I believe. My understanding is that if you have a mix of solar and wind in your grid, you tend to be fine overnight since it's always windy somewhere at night. The challenge for solar&wind is supplying the afternoon/early-evening peak.

Previously you'd conceptually have "baseload" which is sized at the daily minimum, and then "peakers" (or these days just rapid-dispatch gas) which are turned on as needed to supply the daily peaks. With solar this isn't an option; the supply curve is fixed. So you either have to massively overbuild to have enough generation to meet the demand peaks, or have some way of shifting the peak solar generation (midday) to the right, to match the peak utilization. So I think your storage ends up needing to look more like "store 25% of the midday generation to be used by 6pm" (numbers made up for the sake of example). Which seems to be the OOM that these projects from the report are achieving.

Re: Why is hydroelectricity unfashionable?

#175

Post by theptip »

gernb wrote: post #117
theptip wrote: post #79

Earlier quoted context omitted.

Is this supported by the report though? We have yet to build most of the solar we need, and IIUC almost half of new solar is now being built with storage: > At the close of 2021, there were more than 670 GW of solar plants in the nation’s queues; 285 GW (~42%) of this capacity was proposed as a hybrid, most typically pairing PV with battery storage (PV+storage represented nearly 90% of all hybrid capacity in the queu…

You need 2 weeks of storage. https://energytransition.org/2017/07/germanys-worse-case-sce...

You don't use batteries to cover that worst-case scenario.

Re: Why is hydroelectricity unfashionable?

#176

Post by ssivark »

WJW wrote: post #156
didgetmaster wrote: post #147

Earlier quoted context omitted.

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.

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 chemical batteries.

> simply damming up a mid-sized valley can store such a ginormous amount of water that is it hard to compete.

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)

Re: Why is hydroelectricity unfashionable?

#177

Post by _hypx »

philipkglass wrote: post #118
ClumsyPilot wrote: post #43

Earlier quoted context omitted.

> We need storage and pumped storage is the only practical way to get there with current supply chains and technology. This really cannot be enphasised enough - this is the only game in town. The solutions are needed yesterday, and must be built on a massive scale - there is no time for a 20 year R&D to production cycle of a miracle technology. Only hydro does not require any new minerals and mining. The only other c…

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…

The Delta facility is in its preliminary stages. It could be expanded by something like 50x that of current listed capacity.

Re: Why is hydroelectricity unfashionable?

#178

Post by 7952 »

idiotsecant wrote: post #53
theptip wrote: post #52

Earlier quoted context omitted.

Since you’re in the industry I’m interested in your perspective on this report from Lawrence Berkeley lab on integrated battery storage for wind/solar projects: https://emp.lbl.gov/hybrid It seems to me that high capacity integrated battery projects are being built in large numbers, and they are much closer to cost-competitive than I would have though from the general sentiment in the press/HN comments. Obviously the…

Too little, too late unfortunately. The amount of storage available from these projects is tiny and even though it's accelerating it's not accelerating at nearly the level required for the physics of a primary renewable grid to work. Chemical storage of energy is expensive and requires a long supply chain. It's huge that the costs are trending in a favorable direction and maybe eventually we can do all our load balan…

No one technology is accelerating fast enough. But I think battery storage has amazing potential for scalability. It is very suitable for mass production in a factory and produces small components that are relatively fungible. Battery storage sites can be built anywhere, require little civils works, have tiny environmental impact and are very quick to install. And they have the benefit of research and production for cell phones and cars. Massive scalability is hard to predict in advance but is definitely possible. Look at how many billions of arm chips are shipped every year.

We definitely do need pumped storage. Although big civil engineering projects tend to be slow and expensive in most developed economies. And how much of the world actually had the right terrain? My guess is that we will see a few massive projects at one end of a HVDC link rather than scaling up.

Re: Why is hydroelectricity unfashionable?

#179

Post by google234123 »

nostromo wrote: post #165
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…

> hydroelectricity is massively damaging to ecosystems Sure, but compare it with the alternatives. Oil and gas are obviously very destructive of ecosystems. But so are lots of renewables. Here's what a silicon mine looks like (used to make solar panels): https://www.mining.com/wp-content/uploads/2016/02/anglogold-... Here's a lithium mine (used to make batteries): https://assets.telecomtv.com/assets/telecomtv/open-ca…

For uranium, there is 510 million square km of surface area on earth, what's the issue with "destroying" (a lot of the mines are in pretty uninhabitable places) a few sq km out of 510 million to power the human race?

Re: Why is hydroelectricity unfashionable?

#180

Post by plorg »

idiotsecant wrote: post #60
plorg wrote: post #54

Earlier quoted context omitted.

When I was in school for power systems planning the the accepted notion was that pumped hydro storage is cool and great, but like hydropower, it is extremely geographically dependent, and we have basically developed all of the places where it would work (at least in the US), or at least, by order of magnitude, there are not enough remaining untapped hydro-related resources to make a dent in projected storage demand.…

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.

Yes, that is the whole concept.

The question is, is this something that has been re-evaluated? Are there more site locations available than previously thought? Have the economics changed significantly? Was this a known-wrong assumption 15 years ago? Has the public perception changed re: the environmental costs vs benefits of this land use?

I would much rather we build a bunch of pumped hydro than a bunch of chemical batteries, on the belief that it is a much more sustainable technology. But I have seen a lot of online discussion about pumped hydro that treat siting, operational, economic, and land use concerns as if they don't exist, when often they are the primary reasons these projects don't get built.

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