The gravity-based energy storage tower developed by Energy Vault has reached commercialization, with the company signing an agreement with DG Fuels to supply 1.6 GWh of energy storage.
The tower will be charged with solar photovoltaic energy. The dispatched storage will support the creation of renewable hydrogen, biogenic based, synthetic aviation fuel, and diesel fuel.
The agreement is estimated to provide Energy Vault with $520 million in revenues across three projects. The first, a 500 MWh storage tower in Louisiana, is expected to commence in mid-2022. Additional projects are planned in British Columbia and Ohio.
Energy Vault’s design includes a six-armed crane tower that lifts composite blocks using an electric (solar-powered) motor. The lifted blocks are stacked, which creates potential energy. As the blocks are lowered, the energy is harvested and dispatched for use.
The tower is controlled by computer systems and machine vision software that orchestrate the charging and discharging cycles. A range of storage durations from two to 12 hours or longer is achievable, said the company.
Energy Vault said the tower’s design is based on the physics of pumped hydroelectric energy storage. However, as a solid “mobile mass,” the composite blocks do not lose storage capacity over time. The company said the tower has an 85% round-trip efficiency and a 35-year-plus technical life.
The composite blocks can be made cheaply, said the company, using excavated soil from the construction site, waste materials like mine tailings and coal ash, and even fiberglass from decommissioned wind turbines.
DG Fuels will deploy the storage systems to power its carbon conversion fuel process. The company said it is targeting a 93% carbon efficiency rate for its aviation fuel. It will also use the tower’s energy to power water electrolysis for both hydrogen and oxygen feedstock production.
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It seems bizarre to use this to smooth the energy supply for a process that results in fuel (hydrogen) that can itself be stored. I guess you get to spend less on your electrolyzers because you can run them steadily at closer to 100% capacity, but the COST here… Head-scratcher…
Your not getting the point. You stack the blocks in the day time and release the energy at night just like a Big battery. Expect you using concrete instead of batteries and concrete is cheaper also you can mix anything heavy in that concrete mix to make it even cheaper.
Efficiency is probably 20% not 85%. The production cost of energy = $520M/1.6GWh = $520,000,000/1,600,000,000 = $0.325/KWH. Is the 1.6GWH generated per year?
At 20% efficiency, the Energy Vault will generate only 1,600,000,000*0.20 = 320,000,000 KWH or 320MWH.
At $0.325/KWH the revenue = 320,000,000*$0325 = $104,000,000
RETURN ON INVESTMENT (ROI) = $104,000,000/$520,000,000 = 20%
ROI/Year = $520M*0.20 = 10.4 years. If the ROI is more than 3 to 5 years, the project is not economically feasible.
Note: Even the Hydroelectric Power Plants, IC Engine Power Plants, Windmills, Solar Farms, etc, do not have 85% efficiency.
This is a reply to Leonard’s response. It looks like Leonard calculating the cost per GWh by dividing the cost of tower by 1.6 GWh and this would accurate if it was only good for storing 1.6GWh for a single charge but this tower will be charging/discharging thousands of times over it’s lifetime, so dividing the cost by the capacity like Leonard did is not an accurate representation of the cost.
The optimal combination would depend on the relative cost of PV panels, electrolyzers, and energy storage towers, and the peak vs. off-peak cost of electricity.
I wonder whether this gravity-based energy storage could be incorporated into towers for wind turbines. On the other hand, they’re considerably less attractive than wind turbines, and would not be short-term like construction cranes.
There’s no way this could be incorporated into anything resembling current wind turbine towers. There’s not enough volume inside the pedestal tube to store more than a small fraction of turbine output, even if you’re willing to give it up as human access to the nacelle.
This is a wonderful idea!
Some day could convert it to an amusement park ride.
So, pretty much you’re using solar to power motors to pick up blocks which will later drop to power homes. Seems like overkill to produce energy unless you can use gravity energy which would then be stored in batteries, because honestly I don’t see this working out too well.
This whole thing IS a battery, that’s the point. You are storing energy via the raised blocks, using energy from whatever renewable source is abundant/excess at the moment. Then you expend the stored energy by lowering the blocks when your original source is offline/underproducing.
It makes no sense to store energy with a tower and then move it to batteries. This is a substitute for batteries, so the only question is whether it can compete on long-term cost.
The crane would be the battery itself. Traditional batteries are too expensive or too inefficient to use on grid scale.
I am no engineer, but I do understand that the tower is the battery.
We have a hydroelectric reservoir on the coast of West Michigan that fills during the night using pumps during off peak hours, and then it drains during the day to provide additional power during peak times.
I was interested in the gravity batteries that use old mines, although they are still very much on the drawing table.
At the southern end of Lake Michigan is an old granite quarry along Interstate I-94, close to Hammond, Indiana. (You can’t miss it, because everyone drives over / alongside of it. I think it’s filled partially with water. That seems like a good place to put a collection of towers – inside the quarry. I wonder if you could use the water in the quarry to help “float” your bricks in tubes to the top of the battery, using less energy on the pick up…. Then drain drain your tubes before you do the drop?
I would love to see the math after reducing your charging cost by using buoyancy. When I was diving in the oilfields, we would lift all types of pipeline and subsea assemblies off bottom with a simple air hose – move it into position, and set it back down again.
It’s only overkill if you’re interested in continued reliance on petroleum. Sooner or later, we will. It is finite.
Thanks for reading this, if you did. – Kalamazoo
Beats gas compression-no leaks! No hazards! Now how do we lift bricks at night? Oh well. Hydrogen peroxide!
Huh? If it’s paired with solar, the whole point is to lift blocks during the day and lower them at night.
500 Mega watt hours would be lifting 10 million kilograms 200 meters. They already do this in a much better way, in which they pump water from a low reservoir to a higher one. Also, the picture of the lifting device is laughable. There is no need for 3 cranes stacked on top of each other, all of which have the ability to rotate and move the load in and out from the main tower. This thing will be a monstrosity if it is really going to be large enough to provide the energy they say it will.
Awesome those could be underground if it looks that’s the problem and leave solar panels above. I think it’s a great battery I’m sure we could compress air the same way for pneumatics or like the silver mines out west to store it also.
You do realize that digging large enough facility would be so expensive that you are better off with hot salt heat storage? At least those work already and we got proof that they are sensible and fairly cheap solution.
Why don’t you just build an electrolytic generating station using solar panels and wind mills to convert salt water to Hydrogen gas for fuel. The electrodes that need to be submerged in the salt water need double nickel plating so they don’t corrode from the salt.
The Hydrogen gas would just need to be captured and stored.
Very green, I’m excited about this.
This thing is going to look like the first man made airplane with his arms under the wings a real antique
I would think that the capacity of such a system would be very limited compared to hauling heavy stuff (blocks) up a mountain.
I looked up the liebherr ltm 11200-9.1 (it was the first on a biggest cranes in the world list) . It can lift 1200 tonnes 200m. 1.2e6 kg . 200m . 10 m/s2 = 2400MJ = .66 MWh…. build something 3x larger and you can store 2 MWh… there are tesla battery projects litterally 100x bigger!
So DG Fuels is paying $300/kWh. That’s not bad for 1.6 GWh of storage. But if you Do the math that’s a huge number of Energy Vault’s 35t blocks going up and down. I don’t buy it.
Also, is DG Fuels for real? They claim You’re going to make sustainable aviation fuel from biofuels and green hydrogen. This seems like two highly speculative companies getting together to give each other a PR boost.
None
This type of energy storage has existed for centuries. Think about how a grandfather clock works.
Interesting. Big, ugly like power lines, panel farms and wind farms. Space efficiency compared to other storage methods? Same gravity principle as current pump/turbine water storage method but doesn’t evaporate. Possibly more efficient? Needs less storage volume but not order-of-magnitude less.
Correction:
In my previous comment I had stated the quarry was on Interstate -94, on the southern end of Lake Michigan. The quarry is located next to Thornton, on Interstate 80/294, east of Illinois State Road 1. Half of the quarry is flooded. The other half is not…. So perhaps you could use “floats”, per my previous comment.
Thanks