"What if we could move the electricity grid off of fossil fuels" (Tesla)
vs
"Be prepared the next time the power goes out."(Solar City)
10 kWh $3,500 For backup applications
7 kWh $3,000 For daily cycle applications"
From http://www.teslamotors.com/powerwall
Maybe Solar City has been using the ones meant for daily cycle - that would make sense.
"What if we could move the electricity grid off of fossil fuels" (Tesla)
vs
"Be prepared the next time the power goes out."(Solar City)