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Comment by raxxorraxor | Hacker News Reader

It doesn't have to be batteries, it can be pump storage plant or similar installations. Problem that those don't work aren't technical. There are often legislative in nature or the infrastructure for energy transportation is inadequate.

We don't know how feasibly we can get Uranium. The market is unstable right now because of political problems.

The topic is very complex, there are disadvantages with every form of energy production and nuclear isn't an exception. It is only clean if you reduce the question to CO2.

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> it can be pump storage plant or similar installations.

Not sure about the rest of the world, but in the EU we basically maxed out those years (decades?) ago. We won't be getting much more. (I mean, without actual mountains, your pump storage plant is going to be prohibitively expensive.)

> The topic is very complex, there are disadvantages with every form of energy production

True. In France, we had a very recent report[1] that outlines various scenarios towards 2050, and it appeared that the least risky ones involved a fairly diverse energetic mix.

[1]: https://assets.rte-france.com/prod/public/2022-01/Energy%20p...

We have maxed out only hydro power dams.

Pumped storage is not limited to hydro power dams. All you really need is a hill and water, although it costs less with a depression near the hilltop. No watershed needed.

Actually you do not need the hill. An underground cavity suffices.

And, there are numerous other cheap alternatives.

How many joules would your hill/cavity-and-water (or any of your "numerous cheap alternatives" for that matter) would hold for each dollar spent? How would that compare to actual dams? I need sources & links.

Right now I would bet on a highly unfavourable comparison to be honest. Dams have the overwhelming advantage of letting you build a relatively small wall (compared to the lake you're holding), to hold a gigantic volume of water. The mountain an the river are already there, so you don't need to build them.

Ask the people who build them.

Hydro power systems need to store a year or more. Utilities will need at most a few weeks. You don't need or want a river. Dams are f'ing expensive because they need geological support for extreme pressure. An earthen dike suffices if you don't already have a depression.

Only the penstock needs to hold back high pressure.

Give me sources or it does not exist.

I'm aware of dams. I'm not aware of your fancy alternatives. It is therefore reasonable to assume that those fancy alternatives aren't widely deployed. And that the main reason for this is that they're more expensive (per energy unit).

Without sources, your (admittedly plausible) qualitative arguments are just a pretty story.

You are welcome to read up, yourself.

California has constructed dozens of high-altitude, low-head earthen dams on the same principle, over the past century, with penstocks down to lower-altitude turbines, and has lately converted many of them for pumped hydro.

There isn't a single existing pump storage plant in the world that charge with renewables energy and resells it when demand is high. There exist a few proof of concepts, but the only commercial one that I know off do so by charging it from fossil fuel power plants. It act as a large subsidized grid stabilizer for when different fossil fuel power power down.

When there are articles about pumped storage plants the usual problems are not legislative or infrastructure. The biggest issue is that investors don't like to create overcapacity, which mean that there isn't a lot of available renewable energy to buy cheap in order to sell expensively later to recover the cost of storage. When overcapacity occur the enthusiasm for more capacity quickly drop. The secondary issues tend to be more physical in nature. Salt water is very problematic in any situation, so putting pumped storage plants near the ocean has many problems. If you use fresh water you compete with existing utilization, and most suitable locations for pumped storage already have existing hydroelectric power. Fresh water has often a very complex ecosystems and everything from nature to human depend on it.

There are a lot of pump storage plants with various forms of storage mechanisms. Renewables are part of the general energy mix so of course these storage plants also store energy from renewables. In Switzerland and Austria it has become a business because of the overproduction of Germany. Given, they have the matching topography that make them easier to build, but you won't necessarily need that.

Hydroelectric power and pumped storage have synergies, they aren't competing.

Stored power isn't overcapacity. Investors care about expensive energy and renewables are the cheapest and cleanest option.

k, I will bite. Give me a source for a pumped storage facility that buy wind or solar when overproduction causes the prices to be low, and then sells it when the price is high. How much do they pay on average, how much at the point of sale, and how is the ROI per kw/h.

All the existing pumped storage facilities that I know of do not generate their profit from buying low and selling high. They generate profits by providing a service of balancing the grid for short duration so that when a power plant is ramping down, there is a equal force being provided as a service so that the grid doesn't break down. The period of ramping down/up need to be covered somehow, a cost that either the grid operator or the individual power plants need to pay for. The end customer who pays by the kw/h do not see this cost, and it is a very insignificant cost of the whole since it only occur at start and stop.

But I am happy to be proven wrong. Please give me that link of one that buy low and sell high. A commercial operated pumped storage that buy renewable energy when its low and sell when it is high can be scaled up to be used whenever the price difference between low and high is great enough. The cost of operation and investment just need to be low enough that the margin between low and high price points can support it.

Obviously, until you have enough renewable generating capacity to charge your storage, you are not selling stored energy: you sold what you generated.

It is extremely disingenuous, not to say dishonest, to make up scenarios based on status quo when there is still very little renewable generation capacity.

I find equally disingenuous and dishonest to talk about pumped storage for renewables when they do not exist as a viable economical model.

If you want to blame the lack of renewable generation capacity then feel free to do so. Pumped storage could in theory, in the future, when the time is right, be cost effective. We don't know. We are not there yet. Its a financial model to be to be tested when and if we get there.

For now the financial model for existing pumped storage do not care about the purchasing price or selling price, or what kind of power it is being charged with.

What is this "financial model" you imagine?

Utilities will need storage, and will build whatever is cheapest. In some places that will be pumped hydro. End of story.

If you are wondering why a company need a financial viable model to operate on then I can't help you.

So, you imagine a company for each water pump? That is not how things are run where I live.

https://edition.cnn.com/2022/08/01/world/water-battery-switz...

Would this satisfy your criteria? Or are you looking for someone explicitly pairing pumped hydro with other renewables?

https://www.theguardian.com/environment/2016/may/18/portugal...

This was probably made possible by the half-dozen pumped storage hydro plants in Portugal. Now they’re putting floating solar on some as well.

hydro-generated electricity is great, and if they are pumped using renewable energy when supply is high then in theory they could be used to supply that energy when supply is low.

But thanks for that link. Tâmega energy storage complex is actually looking like it will be a real renewable storage, using two attached wind farms. Just like with solar, when renewable is combined with storage it makes more sense when the renewable plants is located next to the storage and operated by the same company.

It would be really interesting to hear some numbers from that plant, like how much money they gain by storing the wind power and selling it at a later point in time. It would also be very interesting to see the cost per kw/h, even through at this point in time with energy prices being what they are, I will likely not matter too much.

Pumped storage has a carbon impact because of the massive amounts of concrete involved. The EU is looking at hydrogen storage instead, with the idea being that the natural gas distribution and storage network will gradually shift over to hydrogen which is produced from surplus solar and wind.

Ofcourse, you first need surplus solar and wind, and that's what the real problem is. There is still plenty of headroom to build more solar and wind for immediate use before we reach the point where some of the produced energy needs to be stored.

Pumped storage does not need concrete.

Ammonia will probably turn out more practical as a transportable storage medium. Hydrogen works stored underground.

I’ve heard using offshore wind turbines to create hydrogen that can be burned is a good way forward

The more we obtain uranium (prospecting, mining, milling...), the more we add to the associated carbon footprint.

Therefore a sustained growth of installed nuclear capacity will lead us to exploit mines at always lowering ore grades => more emissions.

https://www.researchgate.net/publication/222817608_Life_cycl...

https://papers.ssrn.com/sol3/papers.cfm?abstract_id=2051332

Uranium is easier to find than copper and other rare metals, because by weight, it can generate more power. There is uranium in sea water, and I bet it's efficient enough to filter that uranium.

https://inis.iaea.org/collection/NCLCollectionStore/_Public/...

It's more expensive than mining but not by an order of magnitude

Uranium is cheap-ish. Extracting power from it is extremely expensive, and not getting cheaper.

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