this post was submitted on 09 Apr 2024
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My favorite solution for storage of excess power is closed loop pumped hydro. Two bodies of water of different elevations are connected by a generator/pump. When there is too much power, the pump moves the water to the higher lake. When the power is needed, the water flows through the generator to the lower lake.
This could also be made more "local" with https://en.wikipedia.org/wiki/Compressed-air_energy_storage or https://en.wikipedia.org/wiki/Thermal_energy_storage and not reliant on the difference of elevations.
I was talking with an engineer about using a closed loop hydro system at home, maybe in a tower. He said the water wouldn't have enough head to generate electricity. But that compressed air energy storage just might be the solution I was looking for.
the other arguably more effective option for home use is dumping it into heat. Heating up water is a great heat storage solution for radiant heating for instance. Getting that energy back out is arguably harder, but hot water is also pretty useful, so.
Hydrogen fuel cells also. Use the excess to make hydrogen which is simple to store and then use it as a fuel to burn when you have demand. These have started to be put at the bottom of wind turbines so they don’t need to be stopped when the wind is blowing but there is no grid demand.
All these systems help balance the grid too meaning these renewables can be used as base loads instead of dirtier base load generators like coal or gas fire stations.
Hydrogen is famously not simple to store. This is part of the reason that SpaceX rockets use kerosene instead of hydrogen despite the better performance.
Be careful that other rockets run on liquid hydrogen, which should be kept extremely cold. That is the main problem for them. That being said, hydrogen is indeed not easy to store and transport.
True. Liquid hydrogen takes something that's already difficult to work with and adds even more complexity to the system.
i mean, conceptually it's simple to store, you put it in a container, the tricky part is doing it effectively, in a way that won't create a massive bomb. And also at density.
Conceptually, yes, it's like putting it into a container. But it's also made up of the smallest atoms possible, which means it leaks out through a lot of materials. It also reacts with other materials - which makes it a good rocket fuel - but it also corrodes materials it comes in contact with in innovative and frustrating ways.
tell that to the big hydrogen storage industry, im sure they'd love to sell you a subscription for hydrogen storage vessels :)
This is like the gravity generators they're looking to use old mines for.
That's my second favorite solution. One of the cons of the mines is they tend to be too remote from urban areas. But if that's not a factor then you're golden.
It's exactly like gravity batteries, but do get fooled with fancy renders and inspirational music.
Lol that's great, and I was more talking about the ones for mines that already have deep holes, this one is hilariously stupid though. Water does make a lot more sense though, only issue I can see with it would be evaporation.
It's easy to use closed tanks. Mines are still a good site for energy storage, but using water instead of weighted sleds still makes more sense. Simpler over all system.
pumped hydro is pretty slick but incredibly dependent on geology and ecosystem.
Thermal storage is a similar vein, you can even use water, we do use water for this even. Compressed air as suggested, i believe there's a mine somewhere in the US that's used a compressed air storage plant. And of course, motion, flywheels go hard i hear, but i find those to be less preferable, even if high energy density. I imagine those would work better at scale.
That was a very cool read!
The only problem is that it is inefficient
It's more efficient than just dumping the energy, at least some is being stored
That's true
depends a bit on how much energy it costs to build it all, how many decades it should be used how often, and if it's then durable enough to actually earn back the extra energy it costs. It might, just sayin'
We use gravity batteries in the UK. They work well and are pretty good at their efficiency. When you are creating massive systems they are made to last decades. There is always upkeep but it is the same with coal, gas and nuclear plants. All these renewables are far cheaper and far more cost effective than these power stations and for years the main problem has been that wind and solar cannot be used as base load, but with battery storage on a mass scale, thermal and hydrogen storage, we are now at a place where building out far more solar and wind than we need is viable and mixing in these technologies to provide base load and grid stability.
You may be interested in gravity storage. Giant crane picking up giant concrete legos. Neat concept, there's been some pilots.
Nope nope nope.