5 ms·

I'm not familiar with this area. Can you explain why it's a trivial technical matter, and what the solution(s) are?

deleted 4y ago
[deleted]
ncmncm 4y ago
Many billions of dollars are today going into constructing factories worldwide to produce equipment for storage of numerous kinds. It takes time to build the factories, and then time to run them to build out the storage capacity. There is, thus far, little use for storage, because there is not enough renewable generating capacity yet to charge up storage. (Charging it by burning fossil fuels would be stupid.) By the time we need much of it, it will be very, very cheap. In the meantime, building generating capacity and factories is the right use of capital. Although people insisting there is a problem love to talk about expense of batteries, only a tiny fraction of utility-scale storage will ever be batteries. The cheapest storage is gravity, exemplified by pumped hydro, which represents today almost all utility storage. But there are many variations that all work. The only uncertainty is which ones will be cheapest. Each is a different mix of build cost, maintenance cost, storage cost, charging cost, and discharging cost, with capex and opex for each. Different users will favor different places on those axes. Best for most uses are those that cost only capex, and store as much energy as you care to, cheaply. Synthetic ammonia and hydrogen are attractive storage media, despite some higher costs, because they may be sold, and burned in gas turbines. Liquifying nitrogen is extremely mature tech and, like the synthetic fuels, valuable in its own right. Power is extracted by boiling in ambient air to drive a turbine. Compressing air underground, adiabatically, is another mature method. Compressing to a sea-floor bladder through a hose from a compressor onshore, likewise. Turbines, again. Buoyancy, drawing a float down toward a pulley on the sea floor, using a winch onshore; and raising a very, very heavy weight up a disused mine shaft are other, very similar examples of gravity storage. Both have startup time of seconds, and are useful for stabilizing grids. Energy is released by running the winch out, driving a generator. There are various battery chemistries, for cases where batteries are useful at all. All under consideration are much cheaper than lithium. Farthest along may be iron-air, molten-metal, and sodium-bromide, none of which are prone to fires. Storage costs of all kinds are falling much faster than solar generating capacity. Utilities will build whatever is cheapest when they finally need any. As prices change, the mix will change. There is no value in picking just one, and plentiful value in using the right one for immediate circumstances. Nobody needs very much storage, because you can always import and burn fuel. The cheapest fuel will be surplus ammonia and hydrogen, although burning aluminum powder for direct process heat has been used in production at local scales. Scrap aluminum is very cheap.
- Manuel_D 4y ago
  Note that none of these exotic storage systems have ever actually been deployed commercially. Yes, liquid nitrogen is used for things like cooling. But no one has deployed a grid-scale storage system using liquid nitrogen. Liquid hydrogen has been used in rocket launches, but has not been used for energy storage. These technologies are mature in applications besides energy storage. They are not at all mature in the context of energy storage. Grid-scale storage systems using these technologies remains the stuff of prototypes and white papers. This commenter is also incorrect in the claim that there is not enough renewable capacity to charge up storage. California , Hawaii, and other energy markets often hit days of excess renewable production. Proponents of energy storage promised that companies would swoop in to store and resell this excess energy. But this has not materialized, because energy storage is not nearly so simple or cheap as this commenter claims it is.
  - ncmncm 4y ago
    You can insist until you are blue in the face that these are all untried and exotic, but you will be wrong throughout. And you know you are wrong as you say it. If in fact they were exotic and untried, billions of dollars would not already be committed to factories to produce them in industrial volume. The processes involved are used industrially billions of times worldwide every day. You only wish they were exotic because you imagine it would make nukes more appealing. But nothing can make nukes appealing. They get less so with each passing day.
    - Manuel_D 4y ago
      > If in fact they were exotic and untried, billions of dollars would not already be committed to factories to produce them in industrial volume. The processes involved are used industrially billions of times worldwide every day. Yes, for purposes different from energy storage. The massive amounts of ammonia synthesized through the Haber process for fertilizer production does nothing to demonstrate ammonia's viability for electric grid storage. Likewise the hydrogen used in space rockets has no bearing on the feasibility of electrolyzing water, storing the hydrogen, and converting it back to electricity. If anything, the fact that most hydrogen is produced through steam reformation highlights the difficulties of electrolysis at scale. We have plenty of experience with flywheels. Almost every car has a flywheel in it. Does that mean it's guaranteed to be extremely cheap and scalable to store electricity by spinning a bunch of giant flywheels? That's the kind of leap you're making here. When someone actually builds and operates a facility that takes in electricity, produces ammonia, and then taps that stored ammonia to produce electricity later, then we can actually measure real-world cost of such a storage system. Until then, it's just optimistic predictions. And optimistic predictions don't actually store any energy.

deleted 4y ago

[deleted]

Many billions of dollars are today going into constructing factories worldwide to produce equipment for storage of numerous kinds. It takes time to build the factories, and then time to run them to build out the storage capacity. There is, thus far, little use for storage, because there is not enough renewable generating capacity yet to charge up storage. (Charging it by burning fossil fuels would be stupid.) By the time we need much of it, it will be very, very cheap. In the meantime, building generating capacity and factories is the right use of capital. Although people insisting there is a problem love to talk about expense of batteries, only a tiny fraction of utility-scale storage will ever be batteries. The cheapest storage is gravity, exemplified by pumped hydro, which represents today almost all utility storage. But there are many variations that all work. The only uncertainty is which ones will be cheapest. Each is a different mix of build cost, maintenance cost, storage cost, charging cost, and discharging cost, with capex and opex for each. Different users will favor different places on those axes. Best for most uses are those that cost only capex, and store as much energy as you care to, cheaply. Synthetic ammonia and hydrogen are attractive storage media, despite some higher costs, because they may be sold, and burned in gas turbines. Liquifying nitrogen is extremely mature tech and, like the synthetic fuels, valuable in its own right. Power is extracted by boiling in ambient air to drive a turbine. Compressing air underground, adiabatically, is another mature method. Compressing to a sea-floor bladder through a hose from a compressor onshore, likewise. Turbines, again. Buoyancy, drawing a float down toward a pulley on the sea floor, using a winch onshore; and raising a very, very heavy weight up a disused mine shaft are other, very similar examples of gravity storage. Both have startup time of seconds, and are useful for stabilizing grids. Energy is released by running the winch out, driving a generator. There are various battery chemistries, for cases where batteries are useful at all. All under consideration are much cheaper than lithium. Farthest along may be iron-air, molten-metal, and sodium-bromide, none of which are prone to fires. Storage costs of all kinds are falling much faster than solar generating capacity. Utilities will build whatever is cheapest when they finally need any. As prices change, the mix will change. There is no value in picking just one, and plentiful value in using the right one for immediate circumstances. Nobody needs very much storage, because you can always import and burn fuel. The cheapest fuel will be surplus ammonia and hydrogen, although burning aluminum powder for direct process heat has been used in production at local scales. Scrap aluminum is very cheap.

Manuel_D 4y ago
Note that none of these exotic storage systems have ever actually been deployed commercially. Yes, liquid nitrogen is used for things like cooling. But no one has deployed a grid-scale storage system using liquid nitrogen. Liquid hydrogen has been used in rocket launches, but has not been used for energy storage. These technologies are mature in applications besides energy storage. They are not at all mature in the context of energy storage. Grid-scale storage systems using these technologies remains the stuff of prototypes and white papers. This commenter is also incorrect in the claim that there is not enough renewable capacity to charge up storage. California , Hawaii, and other energy markets often hit days of excess renewable production. Proponents of energy storage promised that companies would swoop in to store and resell this excess energy. But this has not materialized, because energy storage is not nearly so simple or cheap as this commenter claims it is.
- ncmncm 4y ago
  You can insist until you are blue in the face that these are all untried and exotic, but you will be wrong throughout. And you know you are wrong as you say it. If in fact they were exotic and untried, billions of dollars would not already be committed to factories to produce them in industrial volume. The processes involved are used industrially billions of times worldwide every day. You only wish they were exotic because you imagine it would make nukes more appealing. But nothing can make nukes appealing. They get less so with each passing day.
  - Manuel_D 4y ago
    > If in fact they were exotic and untried, billions of dollars would not already be committed to factories to produce them in industrial volume. The processes involved are used industrially billions of times worldwide every day. Yes, for purposes different from energy storage. The massive amounts of ammonia synthesized through the Haber process for fertilizer production does nothing to demonstrate ammonia's viability for electric grid storage. Likewise the hydrogen used in space rockets has no bearing on the feasibility of electrolyzing water, storing the hydrogen, and converting it back to electricity. If anything, the fact that most hydrogen is produced through steam reformation highlights the difficulties of electrolysis at scale. We have plenty of experience with flywheels. Almost every car has a flywheel in it. Does that mean it's guaranteed to be extremely cheap and scalable to store electricity by spinning a bunch of giant flywheels? That's the kind of leap you're making here. When someone actually builds and operates a facility that takes in electricity, produces ammonia, and then taps that stored ammonia to produce electricity later, then we can actually measure real-world cost of such a storage system. Until then, it's just optimistic predictions. And optimistic predictions don't actually store any energy.