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Interesting question. I had thought batteries were still orders of magnitude more expensive than nuclear, but just looked up some numbers to try and get an ide
by tempestn 5y ago
Interesting question. I had thought batteries were still orders of magnitude more expensive than nuclear, but just looked up some numbers to try and get an idea. Caveat, these are just numbers I've looked up; they look reasonable to me, but I'm no expert, so could well be making a mistake here. Also I'm just looking at capital costs, not operation.
From what I can find, the capital cost of a new nuclear plant is somewhere on the order of $6M-9M/MW.
On the other hand, a 3MWh grid battery from Tesla runs about $1M. So ignoring cloudy days and just considering providing power overnight (in the winter), you'd need about 14 hours of capacity, so about $14M to provide 3MW, or roughly $5M/MW.
So, in terms of initial capital cost, just the battery portion to handle the overnight gap in solar production would be roughly equivalent to the cost of nuclear, but of course that doesn't account for the cost of the solar panels, nor for the fact that there will be other periods when generation is low. (Although these can be partially dealt with by over-building the renewable generation and using wind as well as solar.) However, the other issue is that the lifespan of grid-connected lithium ion batteries appears to be about 5-15 years, whereas nuclear plants should generally last several decades at least.
So, batteries + renewables are more expensive in terms of capital than nuclear plants, which are themselves quite expensive, but I must admit I'm surprised that the difference isn't even greater. I expect part of the problem is production capacity. You can build a 1100MW nuclear plant, but I expect it would be nearly impossible to buy a 14GWh of grid batteries because the capacity to build them in that scale just doesn't exist, yet at least. Also, as others have mentioned, you'd need a lot of space.
There are other methods of storage that are used, pumped hydro being the most common in large scale, but requiring specific geography. There are other options like gravitational storage with shafts and weights or carts on tracks or what have you, but they're all expensive and/or difficult to scale.
- jpgvm 5y agoIt's also just not a matter of cost but supply. Even if you had the money for enough batteries to meet storage requirements for a fully green grid there is almost no chance you could manufacture enough cells. For the forseeable future all cell production is going to go into cars because Tesla has fat enough margins to absorb increases in battery costs while utility scale storage can't.
- SEJeff 5y agoTesla is putting significant new investment into their energy business. Since they now have almost every major battery manufacturer globally doing business with them, they can shift to the less automotive grade chemistry for their stationary energy storage (power packs and mega packs). Elon’s literal words mention this: https://www.utilitydive.com/news/musk-vows-to-accelerate-tesla-solar-and-energy-storage-business-in-2022/617830/ https://www.utilitydive.com/news/musk-vows-to-accelerate-tes...
- jpgvm 5y agoJust because they will start using LFP for stationary storage doesn't mean they also won't consume all of the LFP capacity for cars and starve out stationary storage again. They already used LFP for all the China built M3s and started shipping those same M3s to non-Chinese markets. Right now all signs point to this continuing. Margins on cars are much better, right now cell supply is so constrained but demand for Teslas is so high they only manufacture the highest spec SKUs. If there are more cells they will go into producing first lower spec cars and then finally stationary packs will get whatever is left (if any).
- SEJeff 5y agoHey, I'm just parroting what the literal CEO of Tesla said, but you're fully entitled to your own opinion.
- ncmncm 5y agoLithium batteries are the most expensive storage alternative, and would compete with automotive use anyway. There are many others, and the only real question is which will be cheapest to deploy. Hydrogen is attractive despite its currently abysmal round-trip efficiency because hydrogen is so massively useful otherwise; the capital equipment for hydrogen production will never be idle even when the underground cavities hydrogen is stored in are considered full. (They never really get full, as such; the pressure just increases.) Efficiency will only ever improve. Practical alternatives to underground hydrogen include liquified air (also industrially useful after the tanks fill), anhydrous ammonia, underground compressed air (again, compressed hydrogen is even more useful), pumped underground hydro, pumped undersea hydro, iron-air batteries (which are extremely cheap, and safe) and even deep mine-shaft gravitational (again, also compatible with hydrogen, compressed air, and compressed hydrogen). Underground hydro is even more attractive than the mountaintop variety because the head may be thousands of meters.
- tonyedgecombe 5y agoWiring up the grid globally makes more sense than trying to store energy overnight.