Technology

I'm not gonna jump on board with this one immediately, there's a few things about it that aren't wowwing me.

1. R-19 is their magical 'denser than water' fluid. They don't have to be so secretive and if they are going to be secretive then I'm gonna assume it's not good for us.
2. it's only really so that you can get the same amount of power from half the height. they aren't selling it as "store twice as much energy", but rather "use in locations that have half as much height". The thing is that the UK has used this kind of power for decades, there are old coal mines and natural cave formations that have large water flows. the water is pumped to the top when you have an excess, and dropped to power during demand. This system seems far better in general, even without the mysterious R-19 fluid. We don't /not/ have height differences in the UK, we have lots.

This is logically efficient from a technical standpoint, but from a practical perspective is a terrible idea. You're only getting 2-2.5x th energy storage out of the process, but in return you're effectively requiring that the entire fluid system be isolated from the environment. Toxicity aside, you can't do anything with the fluid outside of the system. It's probably not something you want local fauna drinking, nor do you want even the slightest chance of this leaking into the local aquifers. I presume that, if it's not fully isolated, the fluid mix balance would have to be adjusted to offset evaporation of the water. And if the plant turns out not to be as great at you hoped hat do you do with the fluid?

Some numbers - a quick google says "According to Ofgem, the typical household in Britain uses approximately 2,900 kWh of electricity annually." I'm going to round that up to 8kWh/day. For a small village of, say, 1250 homes and a three day storage capacity, that's 30MWh. 1MJ (MWs) is 1000kg (one metric ton) stored at 100m - the upper end of this project. Since 3600 seconds per hour x 1MWs = 1 MWh, and we want 30, that's 1MT x 3600 x 30 = 108,000 Metric Tons of this high density liquid needed for a small project to put a 3 power day buffer in place for a town of 1250 houses. WTF are you going to do with 108,000 metric tons of high-density fluid if you decide is isn't working? Your reservoir would only need to be 25% bigger (wider, longer, and deeper/taller) to just do the whole thing with water and you wouldn't need to figure out how to get 3500 full size tanker trucks to transport it all away somewhere for a different project for for de-slurry processing.

Very cool. Do we know what the fluid is? Does it pose any health risks if it somehow leaks into the groundwater?

This is very neat. I wonder what the energy loss is, between what's required to lift the water and what's gained by releasing it. Regardless, eco-friendly high density "batteries" are a great concept.

Running on arbitrage of energy prices gives new meaning to 'buy the dip'.

This is so heartening. Do things smarter and healthier. What a great idea.