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this post was submitted on 18 Jun 2024
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Because batteries aren't as dangerous as reactors, are still making massive improvements on energy density and seem feasible to me. Doing anything useful with nuclear waste has been discussed for decades and no-one has come forward with any really promising results. The waste has been around for long enough if anyone could have done something productive with it it likely would have happened already.
How big would a battery need to be to power a single city of 1000000 for 1day?
Why would you want to do that? Do you fear that there might be absolutely pitch black days with absolutely zero wind?
It's just an example number. No matter what if you are building a grid that has 0 baseload power generation, you need some amount of storage capacity for each KWh of consumption. We can argue how much you actually need, but the fact remains that when you start storing large amounts of power, which you would need in-order to keep a city running during times of reduced generation, it takes a large amount of space.
In order to demonstrate that, I chose a pretty straight-forward scenario of a city of 1million for just one day. Let's assume that this amount of stored energy would be sufficient for a 100% renewable grid for say New York City.
So how much energy storage would be needed and how much space would such a storage facility take up?
The premise of powering a complete city just from one singular facility is a false one. It's unnecessary to build such a facility. You can build multiple smaller ones to supply sectors of a city according to the needs of that sector. The answer also depends on how smart the usage of the power is. Are people using power when it's available? Are people trying to use a lot of power when it's not available but must come from storage? There are so many factors your scenario doesn't take into account. The answer has to be: it depends.
This also feels a lot like a gotcha question not posed in good faith. Because again: you won't need to power anything solely from storage. Wind and sun will always supply a base level of energy.
That is objectively false. The sun doesn't shine at night, and wind doesn't blow 100% of the time. So logically there is some amount of time that you do not get a base load provided only by sun and wind. Hence the need for storage at all. And yes it is a gotcha question, because it's something that anti-nuclear people hand-wave away as if the significant storage infrastructure to support a 100% renewable is just a rounding error, and not worth thinking about.
I did the calculation for you in a different answer, it isn't as unreasonable as you seem to think. Aside from that:
It's extremely uncommon for the whole powergrid to experience zero wind. That's not happening.
What pro-nuclear people are just waving away is so much more though. Space for storage is nothing in comparison.
For the fun of it I did do the calculation. Berlin uses about 12TWh per year. That's about 33GWh per day.
Assuming an energy density of 450Wh/l (a number car batteries apparently were able to reach 2020) that's about 80.000 m³.
A soccer field is about 4000 m². So a space of 10 soccer fields with 20m high battery stacks would do that.
Now assume that energy density will have improved in the last 4,5 years and that maybe storage batteries can be different from batteries in cars and that can go down by a lot. Seems reasonable enough for the biggest city in Germany.
Unfortunately your rough math misses a lot of the picture. This is where the gotcha comes in.
https://electrek.co/2022/10/19/the-worlds-largest-single-phase-battery-is-now-up-and-running/
That is a currently realized grid storage facility, the largest and really only one of it's kind. Today's renewables do not do storage at all, they rely on fossil fuels to make up the baseload.
Some numbers. This facility stores 1400MWh, on 2,000 acres or (~8,000,000 sq meters) Much greater then your 40,000sq meter estimate. Plus you said about 33GWh for a day. Well you'd need ~24 of these facilities to cover just Berlin.
So now the big question, how much energy storage will be needed in a >90% renewable grid? It's obviously a difficult question based on a lot of factors, but one such estimate I found here: https://www.pv-magazine.com/2022/01/24/us-zero-carbon-future-would-require-6twh-of-energy-storage/ ~6TWhrs for the US or about 4300 of those facilities.
Yes it wouldn't have to be monolithic like that facility is, but regardless of how you distribute it, it's a non-trivial amount of space taken up. Totally ignoring the costs, and sourcing the materials for the batteries of such facilities.
But just for fun that facility was ~$550M So you'd need to spend about $2.3T for the initial building of that storage.
Okay so your comparison has a few flaws there. The square meters I calculated were just a reference. The important thing is the volume taken up. If you stack your batteries only 1m high that's gonna cover a lot of ground. You also completely failed to take into account that energy density has apparently 4x since 2020 which shrinks the required volume significantly.
I'm gonna argue that 4000 of these facilities distributed around the whole USA isn't that much. Spacewise the USA is in a very comfortable position compared to European countries.
As for the price: taking the price for a pilot project and assuming that every facility is going to cost that is very wrong. If you're going to build 4000 of them, cost is going to go way down.
But if we are talking numbers here I too have a question. How much land would nuclear plants (and the intermediary storage and final storage for the waste) use to fulfill those 12TWh per year? And how much would those cost to build and maintain? I imagine that a battery facility is way cheaper to operate than a nuclear plant.
You'd be wrong then.
https://en.wikipedia.org/wiki/Palo_Verde_Nuclear_Generating_Station This is a Nuclear power plant in the middle of a desert so no large bodies of water near by, though obviously the design could be adapted to places where water was more plentiful.
It takes up 4000 acres (16,000,000 sq meters) Produces (not stores) 4GW (~32,000 GWHrs annually) For comparison, the US Produces 42400000 GWhrs annually. And it cost $14Billion in 2023 dollars
If I were to replace all of the US's generating capacity with nuclear, fully shunning renewables. it would cost ~$19Trillion and take up 5.3million acres (which is the minimum amount of land that could be taken up by any currently existing power generation system https://ourworldindata.org/land-use-per-energy-source ). But no one wants to do that (although it would be amazing for the atmosphere). Instead we merely need to supplement renewables with base-load power, and we don't actually need power storage at all.
The ideal ratio between renewable power and base-load power I do not know. But during the day in Texas in July it's about 50% higher then at night. https://www.eia.gov/todayinenergy/detail.php?id=42915
So even if we assume renewables don't work at night, base-load only needs to account for ~33% of total electric production at the worst case. Much more manageable then the ~6.5hrs/6TWhrs of energy storage required for a 100% renewable grid to function.
The tl;dr, is that while renewable powered storage is possible, the magnitude of storage required to eliminate base-load generation is VASTLY larger then anti-nuclear advocates realize, and not feasible today (or possibly ever). This belief stems from is fossil fuel propaganda, especially in Germany where the fossil fuel interests understand they have nothing to fear from renewables because a renewable heavye grid is only possible with fossil fuel plants and every year every nation burns more fossil fuels then they did the year before*, Germany included. It will stay that way until mass famine hits and the human population of the earth collapses, unless we stop burning fossil fuels. The only viable non-fossil fuel replacement for our large and growing baseload capacity is nuclear power.
*note that fossil fuels aren't only used for energy production, transportation and shipping are huge areas as well.
Your tldr does not follow from any of the things you wrote above. Considering current energy densities it doesn't seem unfeasible to me to build that storage. And I was honestly surprised how little space this would have taken back in 2020, not to mention that, again, this has been reduced by about 4x today. And it's going to go down further. Your only argument here seems to be space and I don't see that as a big problem. A few soccer fields worth of land distributed in the vicinity of each bigger city doesn't seem like a lot to me.
I do see your point that it is in the interest of fossil fuel to stop nuclear power from replacing them. But I don't agree that we won't be able to build an energy grid without fossile fuels. I believe we can have a grid without both of these technologies.
You seem to be influenced by the "well we won't do anything until we are already burning" mentality which is coincidentally pushed heavily by the fossil industry. It's meant to defer people from believing that change is possible and taking action so we all stay at home and bicker about how cool it would have been if we started change 20 years ago.
It's 1000x "a few soccer fields" for a city like Berlin, and we have zero other working grid level storage facilities in the world at that scale. The handful that do exist are <100MWh, and are meant for specific situations, not for powering 100% renewable cities. No one is building grid-level storage, it's a pipe dream. But it's pushed as a solution because the fossil fuel industry knows it will never happen, but what will happen is more fossil fuel plants will be built.
Have i Not Just calculated that the storage for one day for berlin would be like a few soccer fields? How many days do you think is necessary to be prepared for completely no power input? 10? That's 100ish soccer fields with 2020s battery technology. Stop spreading that bullshit.
Did you miss this?
You estimated 40,000sq meters, but that is off by a factor 2000. This is for a facility that actually exists. Theoretically it could be improved, but those theories aren't being built right now. So based on a grid storage plant that actually exists, berlin would need 48,000 times more square meters dedicated to energy storage then you estimated and in any case, THEY DON'T EXIST and aren't being built.
No I didn't miss that but taking an explorative pilot project as the defacto standard and then rejecting that it might be possible to build something more space efficient is not how the world works