[Schroedingersat]

Hydro makes major changes to the local ecosystem and kills a lot of wildlife that can't breathe water. Although p\enty of things can live in a dam they're not what was there before. It also makes major changes downstram

People like to equivocate this with making entire countries uninhabitable or ongoing destruction.

It also requires vast quantities of concrete (and thus has high one time emissions)

We should still avoid it where we can now that we know better.

[philwelch]

> Hydro makes major changes to the local ecosystem and kills a lot of wildlife that can't breathe water.

It’s not that great for river fish, either.

[ncmncm]

This is not true at all.

Hydro power dams use up a watershed, but those are not being built for storage systems. Pumped hydro storage does not consume a watershed or harm wildlife or fisheries. Pumped hydro does not need concrete for construction.

Please do not repeat this falsehood.

[Schroedingersat]

Please show me a funded or built project (or even a plausible proposal or projection from past and current projects) in the global north that has a lower cost per capacity than Fengning Pumped Storage Station that has the following properties:

- Is at a site of a type that is available with over 100x the capacity of fenging (ie. a hill with a dirt berm would count if there are 4000GWh of hills that could be plausibly used somewhere). If it does this it will help, but is still several orders of magnitude shy of replacing fossil fuels.

- Fulfils your criteria about not destroying an ecosystem.

- Is not built on top of a past project unless there are enough of whatever the past project is to fulfll criterion 1 (ie. a quarry or mine is fine if there are many similar mines or a handful of immense ones) or the cost of repeating the project elsewhere is included.

- Can empty its reserves in 2 months

- Doesn't take up a prohibitive amount of surface area (is at least 20kWh/m^2 or at most 10x the size of a solar array to fill it).

- Has an operating cost under $30/MWh of stored and produced energy

Otherwise pumped hydro does not meaningfully exist as it cannot beat batteries (the thing that is a long way from being good enough to replace fuels) or must destroy a watershed or other ecosystem.

[ncmncm]

There is no need for batteries to "replace fuels". Batteries are useful in places, but fuels, soon sythetic fuels, will continue to be used, particularly for shipping and aviation. There is no need for pumped hydro to "beat batteries". Both will be used.

There is no shortage of land to use for elevated reservoirs, and (again) no implied threat to watersheds in building them. There is no need for "at least 20 kWh/m^2". Reservoirs have many uses that all add value. They may store energy and water, provide recreation, habitat, irrigation, and a site for solar, all at once. There is no need for them to store 2 months' power. There is very little economy of scale: a dozen reservoirs are as good as one. Construction cost is not proportional to capacity. At worst, it goes as the square root, to build the perimeter dike.

Extraction rate is a question of how big and how many Pelton wheels attached to generation equipment you care to install.

And, as always, immediate and local cost will dictate choice. There is no need for universal numbers or a single answer for everybody.

[Schroedingersat]

> There is no need for batteries to "replace fuels". Batteries are useful in places, but fuels, soon sythetic fuels, will continue to be used, particularly for shipping and aviation. There is no need for pumped hydro to "beat batteries". Both will be used.

Further intntional misrepr#sentation. Batteries solve the short term storage problem (especially sodium ion batteries). You're proposing a much worse solution to the short term storage problem as if it is relevant to the remaining unsolved problem (long term storage). Solving the long term (in space or time) storage problem yields solar supremacy -- conditions in which it becomes untenable to open a new fossil fuel facility or even keep existing ones open in 10 years even with trillions in ongoing subsidies.

> Construction cost is not proportional to capacity. At worst, it goes as the square root, to build the perimeter dike.

You need to make it deeper, or use more land. And when the largest project in the world is at cost parity with batteries in spite of using an existing project and river, that's a damning indictment of anything smaller.

[ncmncm]

Again, there is no value in "solving the long term storage problem". Nobody has any such problem. For reasons already explained several times.

The "largest project in the world" is, by definition, not representative.

[Schroedingersat]

> Again, there is no value in "solving the long term storage problem".

There is, because it is the main impedement to the universality of renewable energy.

> The "largest project in the world" is, by definition, not representative.

Yes. Extremely large, recent infrastructure projects by the CCP tend to have vastly lowe stated costs than anything smaller or in another place. If it's unusual\y expensive, show me one which is representitive. Show me a breakdown of a small project (or any project) which uses a typical hill and costs less than projected battery costs at time of completion.