Former Energy Secretary Steve Chu interviewed by NPR (audio and transcript)
MONTAGNE: Similarly, Chu would like utilities to start installing solar panels and batteries storage units in people's homes. The idea hasn't gained much traction yet, but Stephen Chu remains hopeful, and discussed with us how he sees utility companies making this work.
CHU: They will say, allow us to use your roof, allow us to use a little corner of your garage, and we will equip you with solar power. We own it. We maintain it. We're responsible for it. You don't have any out-of-pocket expenses. You just buy electricity at the same rate, or maybe even a lower rate. In addition to that, you have, you know, like five kilowatts of energy storage in your home. And five kilowatts - when you're in a blackout situation and you want to keep your refrigerator going, you want to keep a couple of energy-efficient light bulbs lit at night - that goes a long way.
As installed photovoltaic and battery prices drop this model becomes increasingly practical. Someone will do it as few homeowners are likely to pay the upfront costs themselves. This is a short interview and Chu doesn't have time to mention some other benefits to the utility - like the reducing the need to build large new power plants and the ability to keep the customer. And then there is the issue of grid management - something that is broken today as residential solar becomes a bit more common.
I don't know what the optimal sizing for storage would be. I'm assuming Chu meant five kilowatt hours of energy rather than quoting power. You wouldn't need automotive grade batteries as the environment wouldn't be as harsh as a car. Also energy density isn't as much of an issue. It is conceivable that you may be under $2,000 for the battery and electronics in the near future. Installation costs, much of which is driven by local zoning requirements and non-standard mounts, are now the largest piece of small scale PV costs in the US. If we adopted Germany's regulations we would quickly be under $3,000 per installed kilowatt and that could fall by half in the next few years. It sort of looks do-able.