Upper reservoir (Llyn Stwlan) and dam of the Ffestiniog Pumped Storage Scheme in north Wales
[credit: Arpingstone/English Wikipedia]
The idea would be to have either a smaller site or a lower site, compared to a standard pumped hydro scheme, or a combination of both. Reasonable cost is suggested.
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An energy storage system from RheEnergise could be installed on thousands of hills around the UK, according to the company.
It uses dense liquid, which is two-and-a-half-times denser than water, and could therefore potentially provide two-and-a-half-times the power of equivalent conventional systems, reports Elemental.
As reported by Professional Engineering, the High-Density Hydro systems would be built underground.
Its developers said it could offer long-term energy storage at relatively low costs, with high energy efficiency.
Like conventional pumped hydro, it would use excess energy – such as that generated by wind turbines on a windy day with low demand – to pump the liquid uphill from underground storage tanks.
After travelling uphill through underground pipes, the liquid would then be released to power downhill turbines when electricity demand is higher.
At the end of 2020, RheEnergise received funding from Innovate UK to develop a technology that solves the many disadvantages of other competing energy storage and grid flexibility solutions.
Unlike traditional pumped hydro energy storage, RheEnergise’s HD Hydro operates on small hills rather than mountains meaning there are infinitely more sites available for projects.
Full article here.
Tallbloke's Talkshop 
They don’t say what the name of this dense fluid is. I wonder why not. Is it toxic? A system like this has to be cheaper than batteries.
Nice. Hollowing out the hills AND taxpayers pockets at the same time.
A bit of a duff press release I think, with Innovate U.K. being had for a sucker. or, more likely, it is we the tax payers/consumers who will take up the tab.
I would like to see how they calculate the output of this magical HD fluid especially when it is flow rate of a fluid through a turbine that determines its output, think of all the steam driven turbines that produce electricity.
Something doesn’t add up!
Nearly saturated sodium iodide solution? NaI solubility in water is 277g per 100ml at 20C, so somewhat lower than saturation might give the required density. Not checked solubilities of heavier alkali metal iodides, but they may offer higher densities.
It looks like drinking chocolate.
Video…
But what exactly is this high-density fluid and do we really want it loose in the environment?
It would all be underground in tanks and pipes.
Just how does one engineer a dense fluid at least as viscous as water over a wide temperature range? Or do they plan to get down into the relatively temperature stable bedrock, and customize the fluid? What about leaks? Contamination from circulation?
Creating digging hole jobs. Building back better!
As usual with releases like this, the details are irrelevant. The message is: Net Zero can work!
@oldbrew
What a curious video. I assume those are standard 250 ml. (plastic) beakers yet the RH one only holds 135 units (say 150 maximum) of water. The ‘miracle’ liquid is about 170 units in less volume but (roughly) about 2.5 SG.
I would suggest that it is a suspension of fine solid in water. To get to that approximate density that solid would have to be above 4 in SG so barytes suggests itself – SG 4.3, insoluble, inert and above all else CHEAP. A 50% slurry wouldn’t settle if finely ground and agitated regularly.
Certainly cheaper but less efficient than using mercury (SG 13).
if it was a water reservoir you could fish, swim, or even boat on it giving it community value. This just uglies up the place.
From: How it works
https://www.rheenergise.com/how-it-works
Renewable energy generation is decoupled from energy demand. How’s that going to work out for you?
Oh. It can’t.
Graeme No.3,
You are right – the original article includes a quote from them:
“Chief executive Stephen Crosher told Professional Engineering that the liquid is a fine-milled suspended solid in water, with low viscosity and low abrasion characteristics.” Basically chalk dust.
Another quote from the Profeshunal Injun-earing:
“A large increase in energy storage is required in the UK and around the world, to ensure consistent supply from intermittent renewable sources. In the UK, Aurora Energy Research forecast an additional 13GW storage requirement by 2030. Last week, trade association Renewable UK said the total capacity of the energy storage ‘pipeline’ is more than 22GW.”
GW is power! POWER for chrisake, not energy. Pet hate.
Storage is a head fake, to get you to believe that renewable energy is actually viable.
It takes infinite storage to fix infinite intermittency. You simply can’t build enough. Even if you could, you couldn’t charge it up.