Today the California Public Utilities Commission (CPUC) issued a Proposed Decision which clears the path for economically using battery backup in conjunction with solar and other forms of renewable energy generation. This is good news for existing and prospective solar customers, and great news if you have uneven power usage or high demand charges.
To date utilities have argued that grid-connected batteries are separate energy generation facilities, and hence should be subject to additional fees and regulation; they’ve also argued that since batteries could take energy from the grid they should not be eligible for Net Energy Metering (also known as Net Metering, or NEM) policy.
Net Metering Batteries
Today’s CPUC decision establishes that solar and other NEM-eligible systems with batteries constitute a single generating unit that qualifies for all the benefits of Net Metering. The Proposed Decision specifically orders that:
- Energy storage devices paired with Solar or other NEM generation facilities shall be exempt from the most burdensome utility reviews and fees. Customers with efficient systems shall receive 100% of the NEM credits.
- Residential-scale NEM-paired storage systems under 10kWac don’t have to be sized to customer demand or the NEM generator. There are also some requirements for measuring grid energy drawn into storage.
- Commercial-scale NEM-paired storage systems over 10kW must not exceed the NEM-generator’s peak capacity and shall not exceed 12.5hrs storage/kW. These systems must be designed to carefully meter and control energy flows, but utility metering charges cannot exceed $500.
The Commission will vote on the proposed decision on May 15. You can view the full detail of the Judge MacDonald’s proposed decision here.