storage is only a problem if the global distribution grid is not created. The sun is always shining somewhere, especially if you realize we can leverage space to extend our collection.
cranes are just stupid energy storage (the F=ma bit basically makes this a non-starter) . Water in pumped storage only works out in huge scale (where you have mountains to provide a massive storage pool).
compressed air storage misses the point, use just a little more energy and you can use that energy to thermally separate CO2 from air. (This is a productive use of energy but bad efficiency for storage)
hydrogen production from water is a productive use if we want to remove hydrocarbons from some chemical processes but it is not an efficient battery.
Thermal storage of energy is very inefficient and not a good idea unless you are willing to waste a good deal of available energy.
And flywheels are not even mentioned and very wrong information about Tesla power walls.
There are a great many “promising” technologies in the pipeline, the real question is which of them actually suit our needs and only via real world trials will we discover the flaws and see if the benefits outweigh the flaws.
If you are referring to energy loses due to the large distances and the electrical resistance of the wires carrying that power; you’ll discover those loses are directed related to current and that you can trade current for voltage and trade voltage for current; so we can avoid losses by upping the voltage.
If you are referring to the fact that the Earth’s crust is moving, we can have geologists do some work; estimate the distances spaces where we will be running our wires and put in sufficient slack to cover the time period until the next maintenance window.
If you are referring to weather event induced disruptions in the grid (wind/tornadoes/etc taking out power lines) then you build alternate paths to route around damage.
If you are referring to solar storms and coronal mass ejections, then you need standards in your equipment to deal with out of spec distribution lines.
All of which are technical problems and easy to solve.
If you are referring to the bureaucratic hellscape that is international coordination and cooperation, then yes that is the only huge problem preventing such a solution, despite its numerous global economic and environmental advantages.
It’s not a problem insofar as it costs more than what we are doing now.
It may not happen because renewables and batteries are on such aggressive cost curves that it may be better to just store energy locally or produce more (and thus generate flexible high energy cost economic activity on top of the current energy demand that can happen whenever).
Transmission and distribution currently costs in the ballpark of 3-7c/kWh. Longer distances will drive this up. Overnight-scale storage will drive it down (allowing it to run 24 hours a day at x watts rather than 4 hours at 6x watts).
Solar energy is 1-6c/kWh. Overnight-scale battery is 2-7c/kWh. If you can rearrange your manufacturing so you do the energy intensive bit on a cheap machine on a sunny day and do the labour intensive bit on expensive machines in winter, you won’t consider transmission. If you can’t, you’ll weigh transmission against moving your factory to western australia or morocco or texas. Many processes have a drying or a reduction (removing oxygen with electricity or chemicals made from fossil fuels/electricity) or heating step that fills the first profile.
End result is there will be a mix with countries that have less seasonal variation having an advantage in industries that are less flexible (because hitting the worst-case load will require less infrastructure), and countries with more seasonal variation having a huge advantage in flexible industries (as their winter heating bills will subsidize the free summer solar). Transmission will play a role too (but how kuch is uncertain).
Thermal storage is 100% efficient if you want heat. And with a pond or swimming pool sized reservoir and adequate alumina/silica based insulation losses are miniscule even over months. This is why production is going from effectively zero to hundreds of GWh with the factories being built now – the second 1 Joule of surplus solar is cheaper than 1 Joule of gas, it will replace all new industrial heat (presently this is limited by distribution costs). For work, a carnot battery is definitely competitive with hydrogen.
PHES is perfectly viable almost everywhere re100.eng.anu.edu.au/global/ Although likely not worth building anymore as by the time it is actually needed all-abundant batteries may be cheaper.
Electrolysis (as much as it is vastly overhyped and shoe horned into spots where it is idiotic) is a decent option for rare long duration events. Probably in the form of feed stock for chemical use having a month of buffer to reduce production costs and selling that to CCGT plants for the week or so every now and again that the electricity is more valuable than ammonia or ethylene or whatever.
well no storage can be 100% efficient but you are correct that thermal storage is very efficient if you want a thermal gradient to leverage for heating (cooling as well)
I am assuming you mean Pumped-storage hydroelectricity when you say PHES and no it also falls under F=ma, but when using the terrain is able to increase the amount of mass to a more industrial useful scale. The larger the scale the smaller the losses. Hence most economical when one has mountains for the storage of the water. (metal/plastic tanks on elevated platforms tend to be much less efficient and more expensive).
I guess it depends on what you mean by rare long duration events but yes one can imagine a situation where the burning of hydrogen is justified on an energy needs basis.
well no storage can be 100% efficient but you are correct that thermal storage is very efficient if you want a thermal gradient to leverage for heating (cooling as well)
If I have a room, and I want it hotter than outside now, and hotter than outside later, then putting an insulated box in the room and heating the stuff inside the box, then adjusting the lid to heat the room at the rate I want is 100% efficient. There is no loss eitber in practice or in principle nor any mechanism for one. This is true so long as I want all of the heat, even if I stored high grade heat and run it through a heat engine to make work before heating the room with low grade heat (in which case I might even call it a coefficient of performance of 1.3 or “130%”). I will never match the COP of a similarly engineered heat pump if all I want is low grade though, so in this sense “efficiency” is <100%.
Carnot batteries (where I have a box but don’t want heat now or later but do want work) are quite inefficient (10-50% + a time based loss that only becomes negligible at the GWh scale) , or thermal storage in unheated environments (time based loss) are much less efficient.
A separate heat and cold store from a heat pump feeding a combined heat and power generator is another variation (where a COP might come close to or exceed 1).
F=ma is a bit of a thought terminating cliche (as well as being poor communication and missing a term). E=Fh=mgh. As per my link there are plenty of suitable hills and gullies over about 90% of where people live. A human made structure to lift will always be questionable.
I guess it depends on what you mean by rare long duration events but yes one can imagine a situation where the burning of hydrogen is justified on an energy needs basis
A handful of hours of storage (3-12) can pretty trivially meet loads 90-99% of the time. The remainder tends to be events that are 50-200 hours. Pumped hydro and non-round-trip storage (such as delaying EV charging, overprovisioning an industrial drying step and running it when electricity is cheap, direct ammonia electrolysis for fertiliser during high production times, or storing domestic heat in a pond for winter) can cover most of these.
For the remainder (odd once-in-a-decade weather events or major infrastructure failures) the duration is even longer (100-1000 hours). One strategy is to just keep fossil gas generators around because 100 million tonnes of CO2 emitted and 1100 tonnes of CO2 removed that month may be easier than 0 and 1000. Another is to make something with electricity to burn (which could involve an electrolyser and could involve hydrogen gas storage but does not have to).
Yes in a scenario, which you are in a cold climate which it is always cold outside. Then yes, thermal energy storage would be an extremely efficient option.
It doesn’t apply to most living humans but I grant you that special case.
yes, I did look at your link and noted all of sites are those near mountain ranges; which I certainly grant you is near (within 100 miles of) most human population centers.
Yes in a scenario, which you are in a cold climate which it is always cold outside. Then yes, thermal energy storage would be an extremely efficient option.
I’m not sure I follow why this is an edge case. Space heating indoor areas with surplus wind energy stored in september-november when it peaks is the absolute largest block of inflexible demand for >100 hour storage. With PCM or suitable risk management of high temp. sensible heat it represents the plurality of potential storage demand.
Batteries may still win due to flexibility and prevalence of solar, but I can’t think of a better use case for thermal storage.
It’s also probably the oldest storage tech by about 8000-100,000 years
Long duration storage isn’t used year round. Charge with wind in autumn->don’t burn stuff during jan/dec or dunkelflaute isn’t an edge case, it’s about 10% of all energy and the only real use case where renewables absolutely need LDES.
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