Comment by pfdietz
1 year ago
To get a handle on this, I point people to this fun site https://model.energy which allows you to use historical weather data, various cost assumptions, and optimize for the cheapest combination of wind, solar, batteries, and hydrogen to get steady 24/7 power (which would be a drop-in replacement for a nuclear power plant, essentially.) By disabling the hydrogen you can get a handle on the cost bump for handling the storage with just batteries. In some places, that cost increase would be considerable (for example, Germany); in others, negligible (India).
If you don't like the cost assumptions (they cite sources) you can tweak them and see how the optimum solutions change.
I LOVE that site. The Achilles heel of it is that it doesn’t account for transmission costs, but that’s solvable by just picking a single point (ie no geographic diversity or transmission). Overall, it’s the perfect antidote for all the commonly repeated but wrong claims on the Internet (and this goes for everyone).
It seems to ignore the existence of pumped storage. This is as big or even bigger achilles heel, I think, especially given how common the geography is outside of places like Hawaii and Florida.
The equivalent of Snowy 2 - 350 GWh in lithium ion batteries at current prices would be about $48 billion. The actual cost will be about $13 billion - ~3.7x cheaper.
I like that they use actual historical weather models though. I can't stand op-eds that assume that you wouldn't have a mix of solar and wind and short and long term storage to stabilize power output. It's the first model I've seen that's definitely on the right track.
Snowy 2 loses economically to solar plus batteries.
Note I said solar plus batteries. Many of the ridiculous back of the envelope numbers you see for batteries assume every watt is sacred and must be stored and used.
It's usually cheaper to build more renewables, throw some over generation away and charge batteries for short term balancing when that is actually cheaper.
What you actually care about is electricity delivered and having weeks of storage isn't as valuable when you can rely on the sun rising every day.
Snowy 2 is a particularly bad project:
https://reneweconomy.com.au/snowy-2-much-how-can-a-2-2gw-wat...
but I'd suggest any hydro project where the dam isn't needed for other water based uses e.g. agricultural, is probably going to struggle to justify itself versus more renewables and batteries.
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You can model pumped storage yourself in the Advanced options.
This is really interesting but I am not seeing how it gets to end price. It's saying around 54eur/mwh in the UK with the 2020 technology assumption.
I can see that cost for the solar/wind itself but seems very low for the masses of hydrogen (and associated round trip losses) that it's suggesting. I have read some estimates that it could at least double the price?
If there is otherwise curtailed wind/solar, the RTE doesn't matter very much, since the energy is otherwise thrown away.
I know, but the model above suggests massively overbuilding solar and wind to convert it to hydrogen for storage. That overbuild isn't "free" and I can't see how you can get to €50eur/MWh at the moment for baseload esque power.
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I think the assumption you need to use batteries alone for seasonal storage or that you need a pure zero emissions system is missing the point.
A system that has a gas turbine backup for that non-windy week of winter that happens every 5 years is something of substantial value. Use batteries for capital maximizing daily cycles, and leave coal and gas as "storage" for seasonal emergency cycles, this would be a major, major achievement for humanity.
A general principle of backup systems: if you didn't test it this month, it's broken.
You wouldn't have such a capacity mothballed and forgotten for years, it would have to be maintained and tested regularly. There's a concept in energy market design that helps finance such standby operation called a "capacity market". The plant would sell emergency capacity and get paid for not emitting, just staying available. Failure to respond to an emergency cycle would presumably carry hefty contractual penalties, erasing all the previous revenue.
So this makes the battery and the gas plant compete in the market place, each with it's own economic strengths. The gas plant won't handle daily cycles since the emissions cost would kill it, but it can provide emergency power at a rate and for a duration that would make batteries monstrously capital expensive.
By slowly sliding up the emissions pricing, you will tradeoff the long term emissions versus the energy cost, and let the market efficiently allocate the resources until net zero, or near zero, becomes economically attainable.
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