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Metal-Free 'Rhubarb' Battery Could Store Renewable Grid Energy
sciencehabit writes "A molecule nearly identical to one in rhubarb may hold the key to the future of renewable energy. Researchers have used the compound to create a high-performance 'flow' battery, a leading contender for storing renewable power in the electric utility grid. If the battery prototype can be scaled up, it could help utilities deliver renewable energy when the wind is calm and the sun isn't shining."
Abstract.
"Wow - a rhubarb pie? For me? Let me carve out a slice right now!"
"BZZZZERK!"
Quo usque tandem abutere, Nimbus, patientia nostra?
The summary implies that this technology could be used for large-scale power, but I wonder what the storage density is.
Specifically I wonder how this compares to liquid metal batteries. If everything Professor Sadoway says about the liquid metal batteries is true, those really will provide grid-level storage of power.
lf(1): it's like ls(1) but sorts filenames by extension, tersely
Of course any attempt to store NON-Renewable energy will invalidate the warranty,
Yeah, go read what your own post actually says.
Bart Korman is the sponsor of House Bill 44 (HB44). The bill would allow Missouri utilities – including Ameren, Kansas City Power & Light, and Empire Electric Company – to count ancient hydroelectric plants like the 83 year-old Bagnell Dam towards compliance with the RES.
Clue: Hydro Power IS Renewable Power. Its perfectly appropriate.
In addition, HB44 would allow these utilities to purchase “renewable energy credits” from hydropower from anywhere in the world, of any size. If HB44 goes into law, utilities will change nothing about where their power comes from, and instead Missouri ratepayers would literally be subsidizing large hydropower from faraway places like the Hoover.
In the large picture, it doesn't matter where the power enters the GRID. We've been "wheeling" power for close to a hundred years.
There isn't wind power everywhere, so getting those areas that do have it to put it on the grid makes sense. If there is nobody living
in a a windy area, there would be little reason to build a wind farm there unless you could find remote purchasers.
Your example is seriously flawed. Your understanding of power generation is seriously lacking.
But I gotta say, your tinfoil hat is bright and shiny.
Sig Battery depleted. Reverting to safe mode.
EETimes has a more useful article. This is more like a reversible fuel cell. The working fluid is pumped through the cell, where a chemical reaction occurs. The process is reversible. So there's a "charged" fuel tank, a "discharged" fuel tank, pumps, and plumbing. No info yet on the energy density of the "charged" fuel tank, which is the big question.
In the galvanic direction, peak power densities were 0.246Wcm2 and 0.600W cm2 at these same SOCs, respectively (Fig. 1c). To avoid significant water splitting in the electrolytic direction, we used a cut-off voltage of 1.5V, at which point the current densities observed at 10% and 90% SOCs were 2.25 A cm2 and 0.95Acm2, respectively, with corresponding power densities of 3.342Wcm2 and 1.414Wcm2. ...
The galvanic discharge capacity retention (that is, the number of coulombs extracted in one cycle divided by the number of coulombs extracted in the previous cycle) is above 99%, indicating the battery is capable of operating with minimal capacity fade and suggesting that current efficiencies are actually closer to 99%. ...
AQDS has an aqueous solubility greater than 1M at pH 0, and the quinone solution can thus be stored at relatively high energy density—volumetric and gravimetric energy densities exceed 50Whl1 and 50Whkg1, respectively. ...
As shown in Fig. 2, current efficiency starts at about 92% and climbs to about 95% over ~15 standard cycles. Note that these measurements are done near viable operating current densities for a battery of this kind. Because of this, we believe this number places an upper bound on the irreversible losses in the cell. In any case, 95% is comparable to values seen for other battery systems.
I'm not an expert in any applicable field, but as I have institutional access to the original paper, I scanned it to find what looked to me like relevant numbers. As I interpret the above:
It generates about 0.5W cm^-2 of membrane, so you'd need 2m^2 to get 1 kW output. (But presumably this can be in some compact folded/layered configuration.)
It can charge much faster than it discharges: that 2m^2 of membrane would let you charge at about 4kW.
The storage capacity of the battery fades at less than 1% per charge/discharge cycle.
One litre of reactants lets you store 50Wh of energy (i.e. 20kg for a kilowatt hour)
I think the last paragraph is saying that, neglecting pumping costs, it returns about 95% of the energy you put into it.
Note that we can expect these numbers to improve with further research, but whether there are big improvements to come or only minor ones I couldn't say.
Also: They use a two-reactant-tank set up rather than four tanks, so each tank holds a mixture of the 'charged' and 'discharged' forms of its reactants (e.g. one tank holds a mixture of Br2 and HBr.) I'd naively expected a four tank set up.
Quattuor res in hoc mundo sanctae sunt: libri, liberi, libertas et liberalitas.
Right. Buckets of liquid bromine in a gizmo at home, what could possibly gone wrong?
It's about storing a large amount of energy in a very large amount of electrolyte without similarly large plates and electrical connections. For power storage they are thinking in terms of batteries the size of buildings, perhaps built like current sewerage-treatment plants, to store energy in the electrolyte and move it along, bringing it back to the electrical assembly with pumps as needed. It can be considerably less energy-dense than current batteries in pounds per erg and still be far more practical for the kind of large-scale storage the tech is aimed at.
Brackets contain world's first nanosig, highly magnified:[.]
I used to be a big advocate of the idea of having big batteries to store electricity from unreliable and "green" energy like wind and solar. That was until the cost of wind and solar power really sunk in. Wind power is on about par with peak energy generation like natural gas turbines, which is somewhere between 2x and 3x the cost of typical base load power like coal and nuclear. Solar power is so expensive, and variable (based on location, weather, usage, etc.) that it boggles my mind that any utility would even consider it. Then I recall all the subsidies from tax money spent on this nonsense that it starts to make sense to me again.
The cost of the wind and solar power is high enough that adding to the cost with storage has got to mean the total cost to the utility, and therefore the customer, would be something like 4x what coal and nuclear would cost. Then the size of these batteries would have to be astronomical.
One thing that concerns me is the environmental impact these batteries would have. The materials for the batteries would have to come from somewhere. I assume they would have to be mined out of the ground. These batteries would have to be manufactured, transported, etc. The carbon footprint of pouring the concrete pad these would most likely have to sit upon would have to be quite large.
Another question of environmental impact is, what if there is a leak? The stuff used in the batteries may have been derived from plant material but too much of anything can be bad. I grew up on a farm, I saw what too much water can do. I also saw what too much fertilizer can do, it burns the crops almost as if it was set on fire. What will the liquids in this battery do to crops and water supplies if there is an accidental release?
At least with nuclear power any radioactivity will decay away, with a chemical spill that stuff will always be there. I would much rather see someone come up with a technology to make the production of ammonia cheaper and not rely on natural gas. Ammonia is a fertilizer, a naturally occurring substance, and a fuel. An ammonia leak would still be an asphyxiation hazard, a fire hazard, could burn crops, and could pollute a water supply. However, ammonia is a gas that breaks down into nitrogen and water in the air. The stuff they use in this battery contains bromine and sulfur, what would that do to the water table?
No thanks, I'll take nuclear power instead.
I am armed because I am free. I am free because I am armed.