Californian utilities hit out against battery stored solar power

A dispute over solar battery storage is rumbling in California between the state’s three largest utilities and their own customers.

PG&E Corp., Sempra Energy (SRE) and Edison International (EIX) have each announced their intention to introduce measures designed to ensure that only verifiable solar energy, produced by consumers‘ rooftop installations, is fed back into the grid, according to a recent Bloomberg report.

In response, various solar energy associations and campaigners have voiced their concerns, claiming that once again the solar industry is being unfairly maligned and treated with mistrust.

California’s rooftop solar industry is worth $2 billion, and is the leader among 43 states that currently encourage consumers to install rooftop solar panels and sell the energy they generate to the grid.

According to the SEIA, this net metering scheme accounted for a 78% increase in Californian residential rooftop installations in the second quarter of this year – a surge in growth that has evidently worried the utilities, who are already deeply concerned about consumers producing a larger percentage of their own power.

The battery storage issue opens an as-yet-untouched can of worms. As battery costs fall, customers have been tempted to install solar systems with batteries attached in order to store excess energy that can be used as a backup source of power, or a means to pump that excess energy to the grid in return for lower bills.

Not gaming the system

However, the three utility companies argue that such storage systems could, in theory, be used fraudulently. Consumers with solar panels could fill their batteries directly with power sourced from the grid, and then send it back under a false "clean" label.

Although solar suppliers claim that this is not happening, the industry admits that the technology has outpaced monitoring policies.

"Our rules are not really caught up to effectively include issues with energy storage," Gary Stern, director of regulatory policy at Southern California Edison, told Bloomberg. The company is working with industry regulators to devise fair and reasonable policies for battery storage systems, while State regulators are also drafting official guidance for solar suppliers, solar customers, and the utilities.

Speaking to Bloomberg, Terrie Prosper, spokeswoman for the Californian Public Utilities Commission in San Francisco, said there had been "some complaints from developers in Southern California Edison’s territory that Edison had inconsistently applied the benefits of net energy metering to energy storage projects," adding that the commission will provide formal direction on these issues in the coming months.

The three utilities have said that they will honor net metering guidelines for customers with solar panels and battery storage systems only if they had two separate meters fitted to clearly verify that it is solar energy alone that is being sold to the grid. However, such meters could increase installation costs by more than $1,300, says a utility regulator source.

PG&E Corp. has reportedly rejected net metering applications from customers with both battery storage and solar panels installed, referring them instead to a different program that calls for an interconnection fee. It is also claimed that Southern California Edison has rejected an estimated 60 applications from homeowners with battery backup systems for their solar panels. Meanwhile, Sempra Energy confirmed that although it had received no such applications, it would reject any that came through.

Vote Solar Initiative’s Andrew Browning told Bloomberg that solar panel owners are not trying to "game the system," adding: "The next step is that people with solar and batteries will find a way to make it work without utilities."

As California’s robust solar industry further promotes the wider use of batteries, the dispute requires immediate attention, with the current rules in a state of flux.

One thing is for sure: the issue of solar storage is not going to quietly disappear into the night. Battery costs are expected to fall by as much as 57% by 2020, and the global market for solar storage is forecast to increase from sub-$200 million currently to $2.8 billion by 2018, according to Lux Research.