Energy

Advanced 'high-density waterless hydro' energy plant gets green light

Advanced 'high-density waterless hydro' energy plant gets green light
RheEnergise's system uses a super-dense fluid instead of water
RheEnergise's system uses a super-dense fluid instead of water
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RheEnergise's system uses a super-dense fluid instead of water
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RheEnergise's system uses a super-dense fluid instead of water

This remarkable project promises to open up zero-carbon energy storage to a broad range of areas without huge hills, delivering 2.5 times the power of water-based hydro. A pilot plant has been greenlit, with full-size, grid-scale projects to follow.

RheEnergise's HD Hydro 500 kW demonstrator will soon begin construction at mining company Sibelco's facility in Cornwood outside Plymouth in Devon, UK.

Hydroelectric power systems are the world's leading eco-friendly means of electricity production, accounting for 4,300 terawatt hours (TWh) of output or 15 percent of all electricity. Even though hydroelectrics have expanded in recent years, there's not much room for expansion – potential sites in practical locations are largely saturated.

That's because traditional hydro needs a large body of reliable water, with a high enough head for efficient electricity generation. If you live in the Pacific Northwest, you can run the entire region on hydroelectric, but if you're in Florida, you're a bit out of luck.

RheEnergise Pilot

The same limitation is true for systems that store solar or wind energy by pumping water into reservoirs. If the system losses are reasonable, it's a sound idea, but not if you can't pump the water high enough, in large enough quantities.

Britain's RheEnergise is trying to get around this by replacing the water with a fluid that is 2.5 times more dense than water. It doesn't exactly get rid of the H₂O, but it does mix it with a proprietary mineral powder called R19 that turns the water into a heavy, paste-like fluid.

With this heavier fluid, you can get the same energy storage performance as traditional pumped hydro, using 40% the volume, much smaller tanks, or 40% the height differential between the upper and lower tanks.

More hydro energy storage using less fluid, less infrastructure and lower elevations
More hydro energy storage using less fluid, less infrastructure and lower elevations

In this way, energy storage facilities can be set up in areas with much smaller hills – opening up this clean form of gravity battery to a huge range of locations worldwide that could never use it otherwise. According to the company, there are 6,500 potential sites in the UK alone.

RheEnergy also claims the cost comes in less than that of large-scale lithium-ion batteries. And on top of that, this kind of mechanical storage doesn't have the same leakage and degradation problems as batteries, so reserves can be kept for a matter of hours, days, weeks, months or years, depending on local needs.

All of the above makes this project huge news as the world shifts toward renewable energy grids in the race to decarbonization.

The new pilot facility is being installed at Sibelco's Cornwood site, which produces kaolin for sanitary ware (toilets to you and I), as well as ceramics, tiles, and industrial applications. The pilot plant is funded by the British Government’s Longer Duration Energy Storage (LoDES) Demonstration Programme – which seems an appropriate source of funding for a toilet manufacturer – and it has the support of Devon County Council.

If all goes to plan, this small pilot will soon be followed by much larger commercial projects. "The demonstrator is a trailblazing project for the LDES sector," says CEO Stephen Crosher in a press release, "and will place us in a strong position to build commercial-scale projects in this country and overseas. We have global interest in our technology, from as far as Australia and Chile. We would like to have our first 10MW grid-scale project in operation within 2 years."

Source: RheEnergise, via Recharge News

17 comments
17 comments
-dphiBbydt
I guess this R19+water mix has very low friction. Maybe they are using Teflon coated pipes?
Jf
Sure that's 40% of the head OR volume.
Dogfish
Regarding the low friction comment you could use mercury ignoring cost and toxicity. 1.5 times less viscous than water but 13.6 times denser.
FlawedLegacy
Hi. I must be missing something obvious. What happens to the R19 liquid in the lower reservoir? Is it used for constructing toilets? Or does it need to be cleaned? I'm assuming you're not pumping it back to the top of the reservoir system.
notarichman
@flawlegacy
there is a storage tank at the bottom of the hill. fluid flows down, produces electricity, is pumped back up when there is surplus energy. I've been wondering if mercury
is a good choice also. it is expensive and toxic, so what if there is a leak? they could double wall the tanks and the pipe and put a detection system around them so that
repairs could be made before an actual leak forms. the outer wall could be cheap since hopefully just a little leak wouldn't cause problems?
jzj
This is an energy storage article that does not provide any metric to understand the efficiency, cost, and usefulness of this system. The salient information would be the through-put efficiency, power generation and total energy storage, and the cost per kWh on a levelized cost of energy basis (including cost operations and maintenance over its lifetime). Please provide these figures, the actual important information that matters for energy storage.
michael_dowling
FlawedLegacy: The fluid *is* pumped up to the top again. That's how pumped energy storage systems work.
Michael Noel
Wouldn't this need to be a closed system instead of open like pumped hydro? It would be deadly to any birds etc that mistook it as a lake.
Brashmouse
@Flawed Legacy- It is effectively a potential energy battery, so energy is stored by moving the liquid up hill and returned by letting it flow downhill. To Dogfish's point though I always wondered why the Aztecs coveted mercury so much, but it is a great conductor and as a potential battery it is highly useful since it has such a low boiling point it can be used on a closed system with a thermal input to move to the higher reservoir rather than pumping. Maybe they had more impressive tech than we realized.
NMBill
Reminds me of the Sports Illustrated story back in the 70s at the peak of interest in the Ali-Frazier rivalry. It began, "This year's Fight of the Century. . ."
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