Rather than wondering how we can store all the excess capacity it's probably more cost effective to wonder how we can shift demand.
Aluminum smelters in Germany use gargantuan amounts of electricity, for instance, but they can use 3x as much on Friday when power is cheap than Monday when it's not with relative ease.
Using a powerwall to keep production steady would be a ridiculous waste of money.
Storage heaters need to make a comeback, as well.
I really hope these kinds of things start to increase in popularity, but I think it needs more government intervention for it to happen.
It would probably help if they mandated smart electric storage heaters on new builds but beyond that I'm not sure you need to do much more.
You can rely on people's self interest to buy a new washing machine that saves them money, for instance.
Also, since green tech often saves fewer actual dollars from a consumer's pocket than the "real" cost of the externalities saved, subsidies and/or eco-friendly certification would also be good.
The obvious solution to this is grid frequency. It's already a requirement for solar grid tie invertors for example.
The company I work for has two plants near each other, where one is run in winter, and one in summer, each producing a different product. The workers alternate between which plant they work at depending on the season. The other plant is shutdown for maintenance. By replacing the conveyor belt every year we ensure production never shuts down unexpectedly while people are working, and this more than makes up for the cost of a factory that is idle half of the year.
We have a lot of factories. The above two plants are not the foundry where we pour iron which I talked about in a different thread.
It clearly doesn't matter what percentage of the input cost is energy to whether the plant is profitable. So long as that percentage is non-zero there will always be an energy cost at which the total cost to produce is higher than the market price to sell (ask any industry in Texas).
Clearly there are other factors too, in your example it seems like labour costs are very high or perhaps contractual demands on output mean down time is unacceptable.
The reason an idle machine is bad is because you have to pay interest on the loan (write downs and all that complexity). You also have to pay rent (taxes) on the building they are in. You need to do basic maintenance (HVAC so they don't deteriorate). You need to ensure the machine operator (which might be a rare skill) is available when you put it back to work, which might mean paying the operator to do nothing just so he doesn't find a new job while laid off. All of these raise the input cost of restarting after a long period of being idle - sometimes you are better off scraping the machines and buying new if you need them.
Against that you have demand and ability to store the finished product. Some things can be stored up (just in time calls this bad, but it isn't always a bad thing), while others degrade quickly. Some things your customers will order well in advance so you can plan around demand, while others you get an order for "yesterday" (if only you had a time machine).
Depending on how all of the above work out idle factories have different economics.
https://en.wikipedia.org/wiki/Pumped-storage_hydroelectricit...
One of the potential strategies for dealing with grid storage in Europe is to turn Norway into a battery:
https://www.greentechmedia.com/articles/read/experts-respond...
Very neat engineering.
I'm not saying it isn't neat, but it doesn't scale to as much storage as we need.
https://www.theengineer.co.uk/abandoned-mine-shafts-energy-s...
I'm a sucker for these back-to-basics engineering projects. High tech batteries be damned, let's just use potential energy for storage!
Here is a German article about it. As far as I remember, the real issue is that pumps/generators with the required powers are very expensive. https://www.ingenieur.de/technik/fachbereiche/energie/lageen...
Only if you don't look at all available solutions: https://en.wikipedia.org/wiki/Power-to-gas "P2G is often considered the most promising technology for seasonal renewable energy storage"
I dunno why this is such an unknown technique, natural gas storage is a very old and proven technology. Yet it is ommitted from almost any discussion about the subject...
Also, exist prototype power to gas facilities are ~50% efficient, just for the power-to-gas step. Even with a 66% efficient combined cycle gas turbine, which is the best we have, net efficiency is ~33%.
If you store the resulting hydrogen directly, no carbon source is needed. That makes storage more location dependent, because the cost-competitive options are salt-caverns, but we are talking about long term storage here...
Production of SynGas is more important to replace the current use of ground-pumped methane with CO2 neutral variants.
> Also, exist prototype power to gas facilities are ~50% efficient. Even with a 66% efficient combined cycle gas turbine, which is the best we have, net efficiency is ~33%.
Which is why there are proposals to go purely via hydrogen and reversible oxidation cells. That way you can get up to about 70-80%.
But again, we are talking about long term storage. ALL other options of energy storage are more expensive when you reach the "weekly to monthly" storage timeframe. At that timeframe, the low efficiency becomes irrelevant, as storage cost ($/kWh) is dominating, and we are talking about renewables anayway.
We do have a rather good idea. There are several studies and large test facilities both in Europe and the US. Specifically in the area I was mentioning (salt caverns). From wikipedia on hydrogen storage: "Underground hydrogen storage is the practice of hydrogen storage in caverns, salt domes and depleted oil and gas fields. Large quantities of gaseous hydrogen have been stored in caverns by ICI for many years without any difficulties." "Another study referenced by a European staff working paper found that for large scale storage, the cheapest option is hydrogen at €140/MWh for 2,000 hours of storage using an electrolyser, salt cavern storage and combined-cycle power plant."
There is more here: https://en.wikipedia.org/wiki/Hydrogen_storage
You can also turn CO2 into synthetic oil (Methane, gasoline, Jet fuel, motor oil - your choice of what you want) via known processes. Again the process isn't very efficient, but when the inputs are free who cares. The sum of is carbon neutral.
In order to convert elecricity to methane you first have to REMOVE CO2 from the enviroment. If you subsequently burn that gas, you arrive back at the CO2 level you had before the P2G process.
That of course only works out to net zero when you use co2 that was recently captured, like from waste-biogas or trees.
The big problem with fossil fuels is not directly that they release CO2, it is that they release CO2 that was captured over millenia in the comparatively short timespan of decades.
You can avoid that problem entirely with P2G systems.
The utility keeps the battery charged, uses the power during times of peak load for the grid, and the homeowner can use the battery as a backup power source.
Cars have a fraction of the energy storage capacity of a single battery site and not all cars are connected to the grid at all times and neither will all their stored energy be usable.
Batteries aren't the silver bullet many imaging them to be. The real solution is expanding transmission capacity, building more renewables and supplementing that by nuclear or hydro.
If electricity is going to be so cheap then we can just extract lithium from seawater.
Plus dead lithium batteries can of course be used as a high grade ore.
Assuming lowest demand is at night, that means that building just 3 more batteries you could power the whole state for an hour at night?
A storage battery is not a viable means of balancing demand and supply over a time period longer than minutes.
What's needed is not more batteries but better transmission, more hydro where possible and where hydro is not possible, more nuclear.
And I agree. I worked in solar and storage for a while. It's not a replacement, it's just an extension.
It works out ok for a battery system for a building but anything larger they just don't last long enough
South Australia's population is small, under two million and it's demand fluctuates between 400 - 3000 MW. For comparison, the Canadian province of New Brunswick has a comparable peak demand but fewer than a million people.
The goal of Australia batteries was to normalize short production/consumption fluctuations, not as general universal battery storage to deal with renewable uneven production.
When you come to resell an electric car, the condition of the battery is going to be significant in resale value too.
There would presumably be a zip code lottery element here too - would some areas of a given country make much greater demands of resident's privately owned car batteries than others?
Just set the price at which you are willing to sell so that you make a profit overall.
Are there any examples of pilot schemes that have used cars in this way?
Not to mention I don't think the local grid to houses can support loads of cars suddenly getting charged at once, which is what you want for big wind spikes.
Additionally you could program cars to feed into the grid when the price goes high enough to justify the cost of cycling the battery. This would help deal with unexpected events.
Sometimes I wonder if it would make more sense for individual properties to have their own powerwall type devices to soak up the oversupply during those windy days but in reality the cost of getting one installed is so high that I can't imagine enough people ever doing it, let alone the organization and co-ordination that would be needed from the energy companies.