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Until averaged renewable generating capacity entirely matches averaged demand, money spent on storage is mostly wasted, because to charge it up you would need t
by ncmncm 4y ago
Until averaged renewable generating capacity entirely matches averaged demand, money spent on storage is mostly wasted, because to charge it up you would need to burn fossil fuels. It will be radically cheaper, soon enough.
That is why so little storage is being built, thus far. Costs for storage are falling even faster than wind or solar ever did, because there is nothing to be overcome except limits on scaling manufacturing. The physics of energy storage, chemical schemes excepted, are a matter of freshman physics, so the drive is only how to apply the same principles more cheaply.
Simplicity is the greatest virtue: if you can make a storage system with just one moving part, you have the makings of a winner. Many involve anchoring something to the sea floor: an air bladder with a hose to an air pump and turbine onshore, charged by pumping in air; a float with a cable down to a pulley, thence to a winch and motor/generator onshore, charged by dragging the float down to the bottom; an air tank with an electric pump/turbine just wired to shore, charged by evacuating the tank.
The overwhelming majority of storage will not be batteries, ever. But molten metal batteries have massive advantages over lithium, longevity and heat tolerance probably most important. Iron-air batteries are much cheaper.
Hydrogen and ammonia synthesis will not be as cheap as the others, but have the massive advantage that, because tankage is cheap and transportable, storage capacity is unlimited; and when as much tankage as you care to keep is full, any extra generating capacity yields a high-demand product, thus extra revenue. Furthermore, if your local storage gets looking likely to run dry, you just buy more.
Compatibility with existing natural gas generators is a plus; thus, compressed air, liquified nitrogen, hydrogen and ammonia. Burning something with compressed air increases efficiency.
Energy Vault is bald grift, the Theranos of storage.
- NortySpock 4y ago'money spent on storage is mostly wasted, because to charge it up you would need to burn fossil fuels' Huh? Why would you not charge your utility battery bank with surplus solar or wind power? Bonus: at the point when solar or wind power would be curtailed (when it is generating more supply than the grid demands), is also when the wholesale price per MWh is zero or negative, making it free or profitable to charge your batteries.
- idontwantthis 4y agoThe point is that until all fossil fuel plants are shut down, when you have “excess power” that means you could either shut down FF plant or charge some batteries. If you choose the latter then the FF plant is effectively charging the battery. That is better though for when the renewable plant isn’t running.
- tfigment 4y agoAlso most utilities will not let you charge from grid. Its very hard to get interconnect agreement if a battery is involved
- natmaka 4y agoA distributed approach may solve many problems, enabling charging with surplus produced by renewables, and discharge when people are at work/home (<=> most of them not driving their electric cars): https://en.wikipedia.org/wiki/Vehicle-to-grid https://en.wikipedia.org/wiki/Vehicle-to-grid
- pkdpic 4y agoYeah, I dont know if its pointless to get in early (as if now is really early) given the subsidies in some areas. And it does seem realistic to become an energy independent home for not that much investment which 10 year old me still cant believe is actually a reality. But I do like the idea that these industries might actually be motivated to progress faster now if people hold off on getting on board. Seems like its enough of a reality that they can justify r&d to make the last push toward real competitiveness. Then again my brains fried from work and I don't know what I'm talking about. All I know is I want me some solar panels and an electric F150.
- ncmncm 4y agoDomestic is a whole different domain from utility-scale. The best thing for a house power bank is a used-up electric car.
- ncmncm 4y ago
- adrianN 4y agoSuppose for the sake of the argument that renewables only produced power around noon. If you build more renewables until they produce more power than you need before you invest in storage you run your fossil fuel plants a lot more than if you invest a little in storage to be able to shift massive overproduction around noon to other times of the day. It's probably best if we increase the carbon price until the market figures out how much storage is economical.
- Animats 4y agoThe overwhelming majority of storage will not be batteries, ever. Why not? Lithium iron phosphate batteries work fine, don't cost too much, don't have a thermal runaway problem, are good for 10,000 cycles, require little maintenance, have good energy density per unit volume, and you can buy them right now. They're heavier than lithium ion batteries, but in stationary installations, that doesn't matter. Something better may come along, but they're good enough to deploy now.
- ncmncm 4y agoWe need the lithium for cars. There is literally not enough lithium known of to build enough utility storage. And, they cost way more than alternatives. Utility batteries, where used, will be iron-air or molten metal. Light weight is no virtue in that use.
- ben_w 4y agoThis seemed surprising, so I looked up the estimate of the available lithium reserves (20 million tons, seems low) and lithium needed per kWh (160g), which means we can make up to 113 TWh of batteries. If those numbers are correct and we want cars that each have 50 kWh batteries, we can have up to about 2.2 billion cars, so we either get more lithium (seawater is 1000x more in quantity but IIRC not economical at this time), or we don’t all get to have electric cars. This is making me go back to an older preference of mine, which is to have a really fat wire (order of 1m^2 cross section) going around the planet. Take years (literally) to mine and process that quantity, but in principle you can get winter solstice pre-dawn energy from your antipode. The losses, while large, are not catastrophic.
- dzdt 4y agoThe usual definition of stated "reserves" is the amount of natural resource known to exist in explored, proven deposits. As the demand for a resource increases, more exploration is done and reserves increase. It is wildly incorrect to use reserves as an estimate of the total amount of the resource available.
- pjc50 4y ago> The overwhelming majority of storage will not be batteries, ever Pretty big categorical statement. The problem with the "one moving part" storage systems is that their energy density is surprisingly bad. Gravitational potential energy in particular is terrible. Compressed air systems can be OK, especially the ones using underground reservoirs, but have an efficiency limited by the physics of gas expansion. It's pretty hard to beat redox reactions for energy density. As you say, tankage is cheap, so can this be done with "flow batteries"? But the real reason lithium is winning is the incredible power of path dependence and manufacturing efficiency. Is it the optimal chemists's whiteboard solution to churn out a billion 18650 cells? No. Is it the one that's easier to actually do in the world as it exists today? Possibly.
- ncmncm 4y agoWhat matters is not joules per unit mass or unit volume, but per dollar, and also watts charging or discharging per dollar. Gravity and compressed air systems excel on that axis (Energy Vault excepted, of course). Chemical synthesis systems suffer on cost per watt to charge, but hit it out of the park on joules stored per dollar. Further pluses are bulk-shippable storage media that may be bought and sold, and can be discharged using existing gas turbines, even in places where you have not installed any synthesis apparatus.