Homeowners who have a little bit of extra cash when they install solar panels are often encouraged to add battery storage to their home system. That way, when the local utility goes down, the owners can use excess power from their solar panels to keep their lights on. But a Southern California utility just delivered some upsetting news to owners of those storage systems, raising allegations that the utility is using those batteries as just another stick with which to beat rooftop solar.
Reporter Lauren Poole at RenewableEnergyWorld cites Santa Barbara residents Charles and Elke Hewitt, who bought and installed an Outback 48-volt battery storage system with their solar panels, and Matthew and Elizabeth Sperling, who accessorized their solar panels with eight Concorde batteries. Both homes used configurations that have long been approved for rooftop solar net metering use by the California Energy Commission,
And yet both households were turned down when they applied for SCE's net metering program. Why? Because the utility claims that the batteries could be used to sell electrical power derived from non-renewable sources into the grid in a program designed to promote renewables.
SCE claims that since there's nothing to bar homeowners like the Hewitts and the Sperlings from charging those banks of batteries with power from SCE's grid, then selling it back to SCE as if it's solar electricity. This, SCE says, would undermine the point of the whole net metering program.
"When the system is exporting power back to the grid, it is unclear whether that power is solar power directly from the PV system or power from the battery," SCE's Vanessa McGrady told ReWire. "This creates a complication, because only renewable power exported to the grid is eligible for Net Energy Metering; grid power stored in the battery and later exported back to the grid is not part of the Net Energy Metering program."
McGrady pointed out that the California Public Utilities Commission (CPUC) is in the process of working out a statewide policy on how to incorporate such systems into the grid. That discussion is already in progress, with the CPUC convening an "Interconnection & Energy Storage Working Group" later this year.
These systems are nothing new: batteries have augmented home solar arrays since the 1970s. Some of them, especially in the earlier years of solar, have been in homes that are entirely off the grid, but many have not. Though battery technology continues to evolve, the home battery storage industry did not just fall off the turnip truck: companies like Outback have been around for years, selling battery backup systems too participants in California utilities' net metering programs without much fuss or problem.
Now, suddenly, it is a problem, and California's other investor-owned utilities are following SCE's lead, bouncing net metering applications from applicants with battery systems.
As Charles Hewitt pointed out to Lauren Poole at RenewableEnergyWorld, buying an expensive battery system with the intent of selling grid power back to the utility doesn't pencil out financially. Currently available home storage batteries have limited lifespans: a few too many charge cycles and your batteries need to be replaced, an expensive proposition.
But what makes the utilities' objection even more troublesome is this: California's grid needs storage. In the same week in which the plight of the Hewitts and the Sperlings was making the rounds of the trade press, so were stories like this Reuters piece, which quoted the state's only governor as saying: "We can't just rely on sunlight. We've got to bottle the sunlight."
The state of California has adopted a storage target for 2020: by then, the state hopes to have energy storage capacity equivalent to 1.3 gigawatts of generating capacity.
The state has more than 13 million households.
If each of those households had storage equivalent to a kilowatt of generating capacity, we'd surpass that state target.
California's utilities shouldn't be penalizing customers for installing storage: they should be rewarding them. The state needs power storage, and there's absolutely no reason for all of it to be on the utilities' side of the electric meter.
And yes, battery systems could conceivably deliver dirty power back to the utilities, at least if the costs of replacing worn out batteries drops. But it's worth asking the question: Where do you think those customers got that dirty power from in the first place?