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Why is hydroelectricity unfashionable?

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Re: Why is hydroelectricity unfashionable?

#381

Post by kenhwang »

liketochill wrote: post #380
kenhwang wrote: post #227

Earlier quoted context omitted.

They're currently rated for 20 years of usable life, so you'd replace 5% of them a year. They're supposedly 95%+ recyclable, it's just not currently economically viable to do so since only cobalt and nickel are cheaper to reuse than to newly mine.

Any source for the 20 years? A project I had a colleague working on where the batteries are critical to preventing blackouts since they will result in mothballing of other infrastructure indicated the utility was budgeting for a 5 year lifespan on the batteries.

It's what Tesla puts on their front page marketing[1].

But if you want more detailed breakout, there's this[2] report that you can dig through which states:

> A range of cycle estimates was provided throughout the literature for lithium-ion of up to nearly 6,000 cycles with lower DOD (DiOrio et al., 2015; Greenspon, 2017). The analysis conducted here estimates that lithium-ion LFP can typically provide 2,000 cycles at 80% DOD, while NMC systems provide 1,200 cycles for the same DOD, due to positive electrode dissolution and associated increased capacity loss at the negative electrode. In the next phase, more detailed cycle life data for LFP and NMC chemistries will be obtained. For example, based on 70% capacity at end of life, lithium-ion batteries have demonstrated a cycle life of approximately 8,000 cycles at 80% DOD (R. B. Wright & Motloch, 2001). The calendar life of lithium-ion batteries ranges with some stating > 5 years or as high as 20 years (R. B. Wright & Motloch, 2001) and others in the range of 5-15 years (Dubarry, Qin, & Brooker, 2018). This report estimates a 10-year calendar life at 80% DOD, also assuming 5% of that time will also be allocated to downtime. A cycle life of 2,000 cycles for LFP and 1,200 for NMC is assumed with a 5% increase in total cycles each by 2030.

So with the right chemistry, assuming one cycle a day, assuming 70% depth of discharge is acceptable, 8000 cycles is 21.9 years.

[1] https://www.tesla.com/megapack

[2] https://www.pnnl.gov/sites/default/files/media/file/Final%20...

Re: Why is hydroelectricity unfashionable?

#382

Post by liketochill »

pyrale wrote: post #366
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 hypothesis is that market-driven electricity production simply doesn't handle this correctly. Planification would probably work better, but that's not politically accepted.

The lead times are too long on power plants. It takes years of permitting and studies and then years of procurement and construction for large projects.

Re: Why is hydroelectricity unfashionable?

#383

Post by credit_guy »

pencilguin wrote: post #275
credit_guy wrote: post #260

Earlier quoted context omitted.

> this is the only game in town. There is another game in town. Emphasis on "is", as in present tense, not future. Natural gas power plants. They emit much, much less CO2 than coal. If we use them to only generate electricity when solar and wind are not enough, we end up with much lower emissions than what the trees remove from the atmosphere. We also end up needing to overbuild solar and wind by only about 30%, not…

To explain the economics of pumped storage, you must first understand it. Pumped storage round-trip efficiency is not , in fact, 25%, but routinely above 70%. Nobody pumps water up just 10 meters. It is, instead, pumped (say) a thousand meters up to a reservoir commonly 10 meters deep. A 10m-deep reservoir needs only a cheap earthen dike. A dike is hardly a "megaproject", even if km long. Dikes are low tech. The ener…

I concede the 70%. I agree with your calculations too.

But you also concede that you can use LNG from time to time. Which we can later switch to H2 or NH3.

Right now, all the natural gas power plants in the US produce about 12% of the total (gross) emissions. If we use these plants only when there's not enough electricity from solar, wind, hydro and nuclear, we'll reduce their emissions by a factor of 10.

What is the point in building thousands of reservoirs then? To reduce that 1% to 0%. Which we'd reduce anyway once H2 or NH3 become cheap and abundant enough?

By the way, the EIA made a handy comparison table for various power plants [1].

A "combustion turbine - industrial frame" is by far the plant with the cheapest capital cost, only $785/kW. Conventional hydro is listed at $3083/kw, with a fine print footnote that this cost is the least expensive plant that could be built in the Northeast (where the geography permits).

So, the cheapest possible conventional hydro is 4 times more expensive than an brand new natural gas power plant. My point is, we don't need a brand new one. We can just keep existing ones (and we don't even need to keep them all).

[1] https://www.eia.gov/outlooks/aeo/assumptions/pdf/table_8.2.p...

Re: Why is hydroelectricity unfashionable?

#384

Post by Schroedingersat »

Manuel_D wrote: post #369
pencilguin wrote: post #279

Earlier quoted context omitted.

There is in fact no such issue because literally no one is even considering producing hydrogen for energy storage in that way.

Then how is hydrogen going to be stored? Electrolysis remains either inefficient or expensive.

Inefficiency doesn't matter if you are storing curtailed energy.

If it makes more financial sense and uses less resources to overbuild solar 3x and curtail 60% of the energy than paying for fuel, then you have 2 units of energy you have already paid for spread out over 6-8hrs/day.

As long as using your $300/kw electrolyser at reduced duty cycle is cheaper and less resource intensive than mining and shipping gas, you do it.

Re: Why is hydroelectricity unfashionable?

#385

Post by HyperSane »

theptip wrote: post #215
HyperSane wrote: post #193

Earlier quoted context omitted.

"almost half of new solar is now being built with storage:" I very strongly doubt this, storage is very expensive.

Again, this is quoting from the report I linked up-thread: https://emp.lbl.gov/hybrid . (Linked PDF with lots more detail: https://emp.lbl.gov/sites/default/files/hybrid_plant_trackin... ) > Data on plants under development from the interconnection queues of all seven ISOs/RTOs plus 35 individual utilities suggest that these hybridization trends are likely to continue. At the close of 2021, there were more than 670 G…

storage isn't measured in watts, which is a unit of power, it is measure watt-hours, witch are units of energy.

Re: Why is hydroelectricity unfashionable?

#386

Post by Schroedingersat »

credit_guy wrote: post #383
pencilguin wrote: post #275

Earlier quoted context omitted.

To explain the economics of pumped storage, you must first understand it. Pumped storage round-trip efficiency is not , in fact, 25%, but routinely above 70%. Nobody pumps water up just 10 meters. It is, instead, pumped (say) a thousand meters up to a reservoir commonly 10 meters deep. A 10m-deep reservoir needs only a cheap earthen dike. A dike is hardly a "megaproject", even if km long. Dikes are low tech. The ener…

I concede the 70%. I agree with your calculations too. But you also concede that you can use LNG from time to time. Which we can later switch to H2 or NH3. Right now, all the natural gas power plants in the US produce about 12% of the total (gross) emissions. If we use these plants only when there's not enough electricity from solar, wind, hydro and nuclear, we'll reduce their emissions by a factor of 10. What is the…

> Right now, all the natural gas power plants in the US produce about 12% of the total (gross) emissions. If we use these plants only when there's not enough electricity from solar, wind, hydro and nuclear, we'll reduce their emissions by a factor of 10.

Concluding that we'd only need 2% of the current emissions from this is a bit misleading. The overwhelming majority of emissions currently don't come from electricity and the only way to replace many of them is via electrifying them.

Some can be turned into opportunistic loads, but there will still be a major need for 4-100 hour storage in addition to the seasonal storage (which will be largely achieved via hydrogen or ammonia).

Off river PHES seems to currently be cheaper than other storage, but chemical batteries have a lot of other advantages and may become cheaper.

It also has at least one advantage over conventional hydro in that sites can have a lot more head. This allows the power room to be a lot smaller, and there are many brown field sites where one or both reservoirs are mostly complete (which may make it cheaper in spite of needing two reservoirs).

It's hardly 'the only game in town' though, and it's unclear whether the gap between 'batteries have much lower cost per watt' and 'ammonia has much lower cost per joule in storage' is big eough that 'a hole has zero long run cost' the marginal efficiency gain over electrolysis is worth it.

Re: Why is hydroelectricity unfashionable?

#387

Post by zizee »

pencilguin wrote: post #371
zizee wrote: post #350

Earlier quoted context omitted.

On the depth thing, I really only meant to mean you need lots and lots of water. You could have a shallow basis, and take over a huge area of land, or or smaller amount of land if you have deeper water. Deeper also allows for less evaporation, less land area. Perhaps your and my definitions of favourable geography are different. You need a water source, due to evaporation, you need a big resovoir at elevation, and an…

You don't need a "huge area of land", under any circumstance. Even a football pitch is big enough for useful storage. Permeability is a thing that is controllable. Since there are so very many hills, only the most favorable sites need be considered. The main reason it is not being rolled out much is that it is not time yet to roll it out. You need enough spare renewable generating capacity to charge it from, first, w…

I'm assuming you understand that my statements have a implicit "from an economic pov" when I argue about the practicality of pumped hydro storage, and you're arguing that it is economical to do pumped hydro on a small scale.

My understanding is that it only becomes competitive with other options at a very large scale. A 10 m deep football sized reservoir, at an altitude of 1km above the generator would have approx 13Mwh of energy storage at 100% efficiency (if my math is correct). Battery prices are around $140 per kWh, so a 13 Mwh battery installation is going to be in the vicinity of 2 million dollars.

I would love to see some costs involved in building two man made ten meter deep football field size dams, a large 1km length (it will be quite a lot longer due to it running on a slope) with all the required engineering to run it down a steep incline. The add to that the and generating equipment, and pumps.

Once you've done that, we could compare the operating costs of the two options.

Re: Why is hydroelectricity unfashionable?

#388

Post by pencilguin »

zizee wrote: post #387
pencilguin wrote: post #371

Earlier quoted context omitted.

You don't need a "huge area of land", under any circumstance. Even a football pitch is big enough for useful storage. Permeability is a thing that is controllable. Since there are so very many hills, only the most favorable sites need be considered. The main reason it is not being rolled out much is that it is not time yet to roll it out. You need enough spare renewable generating capacity to charge it from, first, w…

I'm assuming you understand that my statements have a implicit "from an economic pov" when I argue about the practicality of pumped hydro storage, and you're arguing that it is economical to do pumped hydro on a small scale. My understanding is that it only becomes competitive with other options at a very large scale. A 10 m deep football sized reservoir, at an altitude of 1km above the generator would have approx 13…

Agreed, cost matters. While costs of the parts of a pumped hydro system are well-known, which of those parts need to be built for a given installation vary, as do their scale, but most importantly the costs of competing storage media, which are in many cases falling fast.

As for nukes, stable costs make them proportionally less competitive by the day, in the face of cheapening competition.

Re: Why is hydroelectricity unfashionable?

#389

Post by credit_guy »

Schroedingersat wrote: post #386
credit_guy wrote: post #383

Earlier quoted context omitted.

I concede the 70%. I agree with your calculations too. But you also concede that you can use LNG from time to time. Which we can later switch to H2 or NH3. Right now, all the natural gas power plants in the US produce about 12% of the total (gross) emissions. If we use these plants only when there's not enough electricity from solar, wind, hydro and nuclear, we'll reduce their emissions by a factor of 10. What is the…

> Right now, all the natural gas power plants in the US produce about 12% of the total (gross) emissions. If we use these plants only when there's not enough electricity from solar, wind, hydro and nuclear, we'll reduce their emissions by a factor of 10. Concluding that we'd only need 2% of the current emissions from this is a bit misleading. The overwhelming majority of emissions currently don't come from electricit…

Let's say you want to reduce emissions by the equivalent of a 1GW natural gas power station.

Option 1: Build enough solar and wind to replace the electricity generated by the power station; in fact overbuild by let's say 30%. You can afford that because solar and wind are cheap. And then build pumped storage to be able to add an extra 300 MW for a few weeks, when you need that. Decommission the natural gas power station.

Option 2: Don't build the pumped hydro. Build instead twice as much solar and wind as in Option 1 above (for less money than in Option 1, because pumped storage is so expensive compared to solar and wind). When they can't provide 2 GW of electricity, fire up on natural gas power station to make up the deficit. Decommission one natural gas and keep one in partial use. Achieve more emissions reductions for less money.

Which option do you choose?

Re: Why is hydroelectricity unfashionable?

#390

Post by pencilguin »

credit_guy wrote: post #383
pencilguin wrote: post #275

Earlier quoted context omitted.

To explain the economics of pumped storage, you must first understand it. Pumped storage round-trip efficiency is not , in fact, 25%, but routinely above 70%. Nobody pumps water up just 10 meters. It is, instead, pumped (say) a thousand meters up to a reservoir commonly 10 meters deep. A 10m-deep reservoir needs only a cheap earthen dike. A dike is hardly a "megaproject", even if km long. Dikes are low tech. The ener…

I concede the 70%. I agree with your calculations too. But you also concede that you can use LNG from time to time. Which we can later switch to H2 or NH3. Right now, all the natural gas power plants in the US produce about 12% of the total (gross) emissions. If we use these plants only when there's not enough electricity from solar, wind, hydro and nuclear, we'll reduce their emissions by a factor of 10. What is the…

Most of the value in pumped hydro storage, as for chemical batteries, is in load-shifting, particularly from daily collection to evening load. You use it every day, so opex should be minimal.

For tertiary, occasional use, efficiency doesn't matter much, and other considerations dominate. Gas and steam turbines need expensive periodic maintenance after operating for some period, so you avoid running them too much. Fuel costs money, too. (Unless you synthesized it yourself; but what you burn you cannot sell.) But storing liquid fuel is cheap. Shipping it, too.

Transmission lines complicate choices, in large part because they go both ways, and because must be scheduled long in advance to maximize usage because they cost a lot to build. The power they carry might be free at the source.

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