A recent test shows that Quidnet’s technology can store energy in pressurized water underground for months at a time.
Isn’t this basically just fracking without the oil?
This startup wants to use the Earth as a massive battery
Submitted 1 day ago by Aatube@kbin.melroy.org to technology@beehaw.org
https://www.technologyreview.com/2025/07/29/1120765/earth-battery-quidnet/
Comments
skip0110@lemmy.zip 1 day ago
spit_evil_olive_tips@beehaw.org 1 day ago
yep, 100%
that’s even one of their main selling points:
And Quidnet’s approach, which uses commercially available equipment…
this seems to fall into the bucket of “fossil fuel industry looking for ways to diversify and still make profits even as fossil fuel usage declines”
also notable is that fracking for oil is typically a one-time (or at least time-limited) thing. you do it to some rock formation, extract the oil or natural gas from it, and then move on to another formation.
what they’re pursuing here seems to be repeated fracking, pumping water in and back out over and over again. this article about Racoon Mountain in TN for example, mentions a daily pumping cycle - fill up the reservoir using excess nuclear power at night, then drain it during the day.
they’re claiming success based on pumping in water, sealing it up for 6 months, then pumping it back out again. that’s very different from pumping water in and out of this “impermeable” rock every 24 hours, for years or decades (Racoon Mountain was built in the 1970s)
rhythmisaprancer@piefed.social 1 day ago
The article doesn't discuss how they pressurize water. Conventional pumped storage uses gravity,the water isn't actually pressurized itself. Plus the whole liquid thing. But otherwise, neat!
Hirom@beehaw.org 1 day ago
rhythmisaprancer@piefed.social 1 day ago
Ya, usually liquids are compressed with air for any useful stored use. Otherwise something must continually pump. Maybe they are putting a large bladder into the ground?
Kolanaki@pawb.social 20 hours ago
This is gonna upset a dude I know who has a gun for an arm.
Powderhorn@beehaw.org 1 day ago
This doesn’t make any sense. EGS is already a thing, and this doesn’t exactly sound cheaper. The benefit you get from EGS is constant output instead of going through all this trouble to recreate a battery.
I’ll also note there’s no confirmation that this is a closed loop, meaning this could draw a lot of water in a region beset by ongoing drought.
Badabinski@kbin.earth 1 day ago
I wonder if this suffers from the same power density issue as most alternatives to pumped hydro systems. It's REALLY hard to do better than megatons of water pumped 500 meters up a hill.
spit_evil_olive_tips@beehaw.org 1 day ago
yeah, the scalability of this seems like a pretty big challenge
annoyingly, they talk about the amount of water they pumped only in terms of energy (35MWh) and not in terms of water volume.
I think they do that because, if you estimate the water volume…it’s pretty unimpressive.
going off the numbers for Bath County Pumped Storage Station, the largest in the US, and until 2021 the largest in the world:
total storage capacity of 24,000 MWh - meaning that this power station built in the late 70s / early 80s has almost 700 times the storage capacity of this 35MWh demo
between their upper reservoir and lower reservoir, their water capacity is 78.4 million cubic meters. so as a crude estimate, Quidnet’s demo project used ~115,000 cubic meters.
Olympic swimming pool contains 2.500 cubic meters. so, again with the caveat that this is a rough estimate because Quidnet didn’t publish the actual numbers…this demo they’re bragging about involved 45 Olympic swimming pools worth of water.
JohnEdwa@sopuli.xyz 1 day ago
Obviously, assuming you have that hill.
Slightly harder to do in places like the Netherlands for example, where the tallest hill is 322 metres, and the second tallest that isn’t part of that same mountain range near the Belgium border is just 110.
SteevyT@beehaw.org 10 hours ago
In the cycling world it’s kinda funny how people try to make a low climbing century (100 mile route), and where I am I have a glut of choices for centuries with well under 1,000 meters of climbing. I just cleared out a bunch of my routes, and still have two century routes with under 600m of climbing.
Badabinski@kbin.earth 1 day ago
True! I just wonder how much energy they'd realistically be able to store for a given amount of resources. I just wonder if this has the same issues as Lifted Weight Storage, where the energy density just doesn't really make sense once you get right down to it. I don't know the relevant math to determine how much water and at what pressures might be required to scale this up to the 500MWh/1GWh range. It might be perfectly fine.