despite being more than double the capacity of the first Powerwall, and having an inverter built in, the 14 kWh Powerwall 2 is nearly half the installed cost/kWh of its trail-blazing predecessor – making it less like the home battery storage of the future, and more like the home battery storage of the here and now.

the Powerwall 2 just “may be the cheapest lithium ion battery for the home ever made when deliveries start in January.”

According to data compiled by BNEF, Tesla is selling its lithium-ion batteries at retail prices that are cheaper than the average manufacturing cost at most companies, setting a pace for the industry that is beating some of the most optimistic of price projections.

“We certainly expect it will move the market prices downwards as we saw last year with the first Powerwall’,” said Yayoi Sekine, a BNEF analyst who covers battery technology.

Combination of PowerWall and Solar roof top will be the biggest new way to power homes ....