A Chat With Sunrun VP Of Grid Services About Residential Energy Storage
Residential energy storage has the potential to be one key solution for effectively integrating distributed renewables into the future electricity mix. It is already seeing solid traction and offering respectable returns in some markets around the world. Hawaii and Australia, among others with their high electricity prices and vast solar resources, have become hotspots for residential energy storage.
Southern California has very customer friendly net metering policies that allow residential solar customers to lean on the grid as their battery, feeding excess solar power in during the day and drawing it back at night. As more residential and utility-scale solar is added to the grid, it is becoming more and more clear that this model is not sustainable and cannot scale much further. Grid-scale storage is being brought online to absorb the surplus, but more accurate pricing signals are needed to drive customers at the residential, commercial, and industrial levels to install their own electricity storage.
It was this inevitable shift that led me into numerous discussions with local Sunrun expert, Noah Crowe. We both knew there was much more to the conversation, so I reached out to Sunrun to get in touch with an expert on storage. They graciously connected me with the Sunrun VP of Grid Services, Audrey Lee, for a chat about the work they are doing in residential energy storage.
We initially discussed Sunrun’s residential solar + storage offering, which it has dubbed Brightbox. This consumer option went live in Hawaii and California last year and was recently launched in Arizona. The solution allows residential solar customers to store the electricity generated by the onsite solar system in an onsite battery, and then use electricity from that battery at night. Audrey shared that Sunrun currently has “over 2000 Brightbox orders” in California and Hawaii and is expecting a sunny reception in Arizona.
Audrey shared that Sunrun views storage as a competitive upsell and that, “long term, I could see every customer installing storage with solar.” It isn’t just good business for Sunrun that makes storage a good fit with solar, but rather, it is a technical requirement to continue with more residential solar installations: “to get a higher penetration of residential solar, we really need residential storage.”
Hawaii is a good case study for this imperative, as the local utility has already hit the cap for the number of residential solar customers that are permitted to feed excess electricity generation into the grid. That has created a ripe market for storage, as it is now essentially required to install a new residential rooftop solar system.
“With solar, they can continue to operate: charge up the battery when the sun is shining and use it from the battery when it is not.”
Back on the mainland, the value proposition in California is not as straightforward, though a compelling case can still be made for residential storage. Many users are simply looking for a battery backup solution that will allow them to keep their home running in the event of a power outage.
The system also has the ability to help customers on a time-of-use (ToU) rate plan save some cash. Rates are currently the highest during the day, when the sun is shining and air conditioners are cranking, meaning that the solar power generated has the most value to the utility. Conversely, as the sun goes down, so do rates, meaning customers can use any power needed from the utility at the lowest rates available. The battery is able to intelligently maximize these balances for the customer.
Looking toward the future, the battery system protects customers from future ToU rate changes. As more and more solar comes onto the grid, it is expected that the peak usage will shift from mid-day to the “duck curve” that is becoming more and more pronounced (PDF) due to the massive new production from solar.
All of the power flows from the solar system, in and out of the battery, and to the utility are visible to the customer from the MySunrun app — though, the actual logic dictating the flows are managed by Sunrun.
“We are essentially selling storage as a service. Customers don’t want to have to manage their battery. We take care of that and manage storage to maximize savings while ensuring capacity is available for emergencies.”
Managing the storage system in house allows Sunrun to partner with utilities directly to maximize the benefits of the system to the customer and to the grid…..