Matthew MalthouseThe latest auction in China offered 25 gigawatt hours of capacity for lithium iron phosphate (LFP) batteries
Price average average was $US59/kWh, a 30 per cent drop from 2024 costs.
Steve Hayes@calmeilles That's reasonable for batteries that'll be cycled more or less daily. Say you need 10% pa to cover capital cost, depreciation and (very low) operating costs. So that's $6 per kWh per year. At say 200 cycles per year, it's 3 cents per kWh stored and there's probably a good profit to be had. But longer term storage remains a problem. Cycle 3 times a year and it's $2 per kWh which is hopeless (and there's probably not enough lithium in the world). Maybe a different chemistry?
Practically speaking what use cases can you imagine that would cycle 3 times a year?
@calmeilles Maintaining electricity supply during a period of low sun and wind which might last for several weeks. Matching peak solar output in summer with peak heating demand in winter. It's a mid-latitude, maritime climate thing.
One assumption there is that solar is the only source. That seems unlikely to be the case.
Another, that battery stations are built solely for this purpose without also being utilised to smooth shorter term supply fluctuations. That would be poor design.
Given the real cost I wouldn't expect to see any installations built in this way.
@calmeilles it would be expensive to build enough solar to supply the full load when the wind isn't blowing plus enough wind to do the same when the sun doesn't shine and there would still be periods when neither was producing much. Batteries might be even more expensive but their prices are falling and maybe sharply as types using only common elements (sodium) are introduced. Hydrogen is another approach but seems to have fallen out of favour.
@calmeilles as regards short versus longer term storage, it's a matter of numbers. To supply the load for 14 days takes 28 times more kWh storage than for 12 hours. Depending on battery characteristics, you might use the same batteries for both but you'd only be short-term cycling 1/28th of the capacity you'd paid for. If the batteries have limited charge cycle life, you could rotate through different battery banks for short term storage and level the wear.