"Models 10 kWh $3,500 For backup applications 7 kWh $3,000 For daily cycle applications" From http://www.teslamotors.com/powerwall http://www.teslamotors.

"Models 10 kWh $3,500 For backup applications 7 kWh $3,000 For daily cycle applications" From http://www.teslamotors.com/powerwall http://www.teslamotors.com/powerwall Maybe Solar City has been using the ones meant for daily cycle - that would make sense.