Do you have empirical evidence? Some grid scale batteries, especially of the “server rack” commodity style that use LFP, should have 5 years of life already and by your model about to fail. I would argue that such failures observed over the tens of thousands of them deployed in various grids would be strong direct evidence of an n cycle field lifespan. I do not see any data in this paper collected from field batteries, merely a model that may simply not be grounded.
Are grid operators assuming they have 15-20 year service lives or 5?
Yes, some people have needed to replace batteries in some large storage systems, and/or augment them with extra capacity to balance degradation. I haven’t seen any good data on this, because most operators have no reason to share it. Also, due to rapid growth, most of the volume of first replacements is still upcoming.
If I read the paper right, it refers to degradation similar to leaving the cells at 100 percent SOC. It should be immediately measurable and catastrophic, leading to complete storage failures. Do you not have any direct measurements?
It’s an extremely falsifiable thing, there should be monthly capacity loss and it should be obvious in 1 year the batteries are doomed.
Someone could buy an off the shelf LFP battery and cycle it daily and just prove this.
Do you have empirical evidence? Some grid scale batteries, especially of the “server rack” commodity style that use LFP, should have 5 years of life already and by your model about to fail. I would argue that such failures observed over the tens of thousands of them deployed in various grids would be strong direct evidence of an n cycle field lifespan. I do not see any data in this paper collected from field batteries, merely a model that may simply not be grounded.
Are grid operators assuming they have 15-20 year service lives or 5?
Yes, some people have needed to replace batteries in some large storage systems, and/or augment them with extra capacity to balance degradation. I haven’t seen any good data on this, because most operators have no reason to share it. Also, due to rapid growth, most of the volume of first replacements is still upcoming.
If I read the paper right, it refers to degradation similar to leaving the cells at 100 percent SOC. It should be immediately measurable and catastrophic, leading to complete storage failures. Do you not have any direct measurements?
It’s an extremely falsifiable thing, there should be monthly capacity loss and it should be obvious in 1 year the batteries are doomed.
Someone could buy an off the shelf LFP battery and cycle it daily and just prove this.
That is literally what the linked paper did as a basis for their modelling. But of course they used multiple cells.
Right, the actual batteries you can buy with Chinese EV grade lfp cells is what to test. There are many variables here.