NEM Multiple Meter Aggregation is Live

The California Public Utilities Commission (CPUC) voted out and adopted the finalized rules for net-energy metering (NEM) multiple meter aggregation yesterday. The vote was the final step in a long rulemaking process, in order for the program to go live in the San Diego Gas & Electric (SDG&E) and Southern California Edison (SCE) service territories.

What is NEM Multiple Meter Aggregation?

A utility customer that has multiple meters on their property is now able to design, install and interconnect one solar system, and virtually assign credits from the production of the system to multiple meters located anywhere on the property or on an adjacent property they own.

The old rules required a solar installer to design and install a separate solar system for each individual meter, which entailed sizing and interconnecting a unique inverter for each meter. If a customer wanted to offset the load of 10 meters on their property, a solar installer needed to size and install 10 separate systems, with ten separate inverters. NEM multiple meter aggregation changes that by allowing a property owner to assign (or “wheel”) production credits from their solar system to multiple meters located on the property. Here’s the actual language:

“An eligible customer-generator with multiple meters may elect to aggregate the electrical load of the meters located on the property where the renewable electrical generation facility is located and on all property adjacent or contiguous to the property on which the renewable electrical generation facility is located if those properties are solely owned, leased, or rented by the eligible customer-generator. For the purposes of this paragraph, parcels that are divided by a street, highway or public thoroughfare are considered contiguous, provided they are otherwise contiguous and under the same ownership.”

Policy Background:

The legislation that made NEM multiple meter aggregation possible was Senate Bill 594, was signed into law by Governor Brown in September of 2012. The legislation effectively amended California's existing net metering law to allow customers to aggregate renewable energy system production across multiple meters on their property.

One point of disagreement that delayed the implementation of this program was the acceptable fee structure that SDG&E and SCE would charge in order to recover administrative billing costs. Ultimately the CPUC ruled that both SDG&E and SCE should replicate the fee structure adopted by PG&E, which they determined was fair and equitable. NEM multiple meter aggregation has been live in the PG&E territory since February of this year. The final approved fee structure calls for each account to pay a one-time setup fee of $25 per meter, capped at $500. Also the customer is required to pay a $5 per month ongoing fee for each participating meter. The CPUC final resolution did include language that said after one year the investor owned utilities (IOUs) can adjust these fees, if they demonstrate they aren't enough to cover their administrative billing costs.

You can read the full CPUC - NEM multiple meter aggregation resolution here.