On 20.05.19 02:02, Chris Albertson wrote: > Total KWH meant if you have a 10 KHW battery and you chrage and discharge > it 200 times then you have 2000 "lifetime" KHW > If you can charge the battery 400 times then you have 4000 "lifetime KWH. > The second battery as twice as much value.
As a first approximation, yes, but the value is also affected by loss of utility through degradation of capacity over cycle life. Looking at: "In comparison, the Tesla Powerwall is a 6.4 kilowatt-hour battery and only 5.44 kilowatt-hours of that is actually warranted to be usable. But after the first 2 years that drops to 4.6 kilowatt-hours. And 3 years later it drops down to only 3.8 kilowatt-hours of warranted storage." from: https://www.solarquotes.com.au/blog/redflows-zinc-bromide-zcell-battery-may-have-the-edge-over-lithium-ion/ I'm reminded that phone and laptop battery capacity doesn't take long to nosedive. That's a much bigger problem with house batteries. One outlier is the ZnBr flow battery - it is claimed to maintain capacity for its full life, with efficiency falling instead. As that can be compensated by adding cheap solar panels, it's a very interesting variation in the cost/energy equation. OK, reasonable efficiency is still necessary, especially in polar climes in winter, but in generally sunny Australia, it's just the high initial cost which detracts. Erik P.S. That web page is inordinately folksy, but if you skip the waffle, it does cover some of the battery's properties. _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
