I'm interested in getting a Powerwall2 for emergency backup purposes. Is the main purpose of the Powerball to shift TOU or as a backup in case of power outages or some combination of both ? Does it even make sense to have a Powerwall with the sole purpose of backup power ?
Thanks !
Might make sense in some areas where power is almost 'Free' at night and/or have very high
daytime rates or with PV Solar without net metering but $6,200 for 14kWh Powerwall = $442 / kWh.
That means that even if you charge it with 'free' power that is 'worth' 0.125 per kWh (Texas)
you would have to cycle that Powerwall battery every single day for approx ten years
($442 / 0.12 = 3,536 / 365 = 9.79 years) just to break even without accounting for
additional charge / discharge losses. (assuming you charge it daily)
I think / hope there will be growing trend where the utilities actually start paying the
customer to charge our cars at night. That might reverse the payback equation and quick.
Here in Texas we produce tons of wind power that goes wasted at night. During the
day we use what ever is available (clean and dirty) to meet the real time demand.
The utilities have to build more and more expensive (peaker) power plants just to
meet that summertime peak demand being made worse by the popularity of EVs.
Every EV charging during the day is using power roughly equivalent to home
electric home oven on 550 deg with the broiler on. That's a lot of daytime peak
demand power.
Just a side note .... a single 14kWh Powerwall can only store 56 miles of range (approx)
for a Tesla. That means that a fully charged 100D is like $43,400 worth of Powerwalls.
It would be sweet if the Tesla could feed power back to the Powerwall and house.