2 ms·

That kind of idiot would hopefully also not do the math on how many cycles electric vehicle batteries can take and thus how much such a battery pack depreciates

by WJW 4y ago

That kind of idiot would hopefully also not do the math on how many cycles electric vehicle batteries can take and thus how much such a battery pack depreciates per cycle. In all but the most extreme grids, the amount of depreciation is vastly larger than the amount of money you could possibly hope to gain by arbitraging electricity prices. There is a reason that true large-scale storage is so far almost exclusively the domain of pumped hydro, which has a much longer life in terms of cycles than batteries. (Before anyone brings up the Tesla battery in Australia, that is an edge case where the grid needed more capacity for grid stabilisation. Almost anywhere where you would find one of the electric pickups from the article would also have a stable enough grid that you cannot replicate that with the car battery.)

bryanlarsen 4y ago
Cycling a battery from 75% to 25% and back puts very little wear on the battery. A battery might have a 3000 cycle lifetime, but that's a 100% -> 0% -> 100% cycle. 3000 cycles is already 10 years at just under 1 cycle per day. Adding an order of magnitude more cycles by cycling between 75% and 25% gets you a century. Something else is going to die first.
Ottolay 4y ago
Lithium Ion batteries degrade very little with low C mid range charge cycles. The time/temperature/SoC degredation is greater. Hence why you don't want to leave a battery sitting at 100%.
_ea1k 4y ago
Someone else linked this battery earlier: https://signaturesolar.com/eg4-lifepower4-lithium-battery-48v-100ah/ https://signaturesolar.com/eg4-lifepower4-lithium-battery-48... 5kwh for $1500 with 3000 cycles is $.10/kwh. I'm oversimplifying here as the real cost is higher, but the arbitrage opportunity only has to offer ~$.20/kwh to be generally profitable with a battery like that. Some time of use plans are already there daily. I don't think the person taking advantage of this sounds like any "kind of idiot".

by WJW 4y ago

bryanlarsen 4y ago

Cycling a battery from 75% to 25% and back puts very little wear on the battery. A battery might have a 3000 cycle lifetime, but that's a 100% -> 0% -> 100% cycle. 3000 cycles is already 10 years at just under 1 cycle per day. Adding an order of magnitude more cycles by cycling between 75% and 25% gets you a century. Something else is going to die first.

Ottolay 4y ago

Lithium Ion batteries degrade very little with low C mid range charge cycles. The time/temperature/SoC degredation is greater. Hence why you don't want to leave a battery sitting at 100%.

_ea1k 4y ago

Someone else linked this battery earlier: https://signaturesolar.com/eg4-lifepower4-lithium-battery-48v-100ah/ https://signaturesolar.com/eg4-lifepower4-lithium-battery-48... 5kwh for $1500 with 3000 cycles is $.10/kwh. I'm oversimplifying here as the real cost is higher, but the arbitrage opportunity only has to offer ~$.20/kwh to be generally profitable with a battery like that. Some time of use plans are already there daily. I don't think the person taking advantage of this sounds like any "kind of idiot".