5 ms·
That seems kind of expensive still. Grid power is around 7 cents / kwh for comparison so you need over 3,000 hours of usage to break even on a depreciating bat
by mdorazio 7y ago
That seems kind of expensive still. Grid power is around 7 cents / kwh for comparison so you need over 3,000 hours of usage to break even on a depreciating battery. Or for comparison, new 18650 cells are around $2 each in bulk, so you could get almost the same kwh storage (probably 5% less) for the same price, with a lot more cycles left.
- cma 7y agoI don't know how much it adds, but the Tesla model S module has to have rigidity for the car and some puncture resistance etc. that might not be needed in a power application right? It also may need to have a much higher peak discharge and charging rate and cooling to accommodate that.
- mdorazio 7y agoThat's true. A vehicle-grade battery pack should also already come with the wiring built in so you can charge and discharge all the cells from a single point without having to make your own harness. Still, though, I'm not convinced buying a used Model S battery pack is a good deal unless you have an application that specifically needs it.
- m463 7y agogrid power where? For PG&E in california, grid power is .23/.29/.51 per kwh (tiers depending on usage)
- mdorazio 7y agoHere in Portland [1]. [1] https://www.portlandgeneral.com/residential/power-choices/basic-service#:~:targetText=Pricing,kWh%3A%207.572%20%C2%A2%20per%20kWh https://www.portlandgeneral.com/residential/power-choices/ba...
- cullenking 7y agoYou are forgetting delivery charges. It's between 0.11 and 0.12, with appropriate charges.
- mdorazio 7y agoThat's fair, but it doesn't really change the main point that you're looking at a stupid amount of hours equivalent to get to break-even while adding hundreds of charge cycles to an already-degraded battery. I can't really see this being a positive ROI purchase unless you want to use it for a vehicle. Used battery prices need to come down another 20-30% before it will make sense.
- erichocean 7y agoI would love to get that from PG&E in California. As it is, and with the high cost of energy in datacenters (because it's triply redundant, etc.) I've been researching natural gas power generation at home to power my render farm, instead of putting it in a datacenter. I can do it for about $0.17/kWh, which is cheaper that the energy I get from PG&E. Fixed cost for the generator is about $7K to power the farm.
- jamiek88 7y agoi'd factor in wear and tear on the generator there too they aren't meant for 24/7 use.
- 8bitsrule 7y agoI'm surprised seeing that power-source chart for OR. In particular 60% NatGas+Coal, 30% hydro, 6% wind. Any idea why so little wind-power development yet?
- caf 7y agoIt's not 3000 hours of usage, it's 3000 cycles.