Apply for NEM - Requirements

Effective January 01, 2010, customers installing inverter-based systems will no longer be required to include an AC disconnect switch when the facility has a self-contained electric revenue meter (i.e., 0-320 amp socket-based meters or 400 amp K-based meters).

This type of meter is used by the vast majority of all SDG&E customers.

To accommodate this change while maintaining utility operating safety needs, the revenue meter, when appropriate, may be temporarily removed by SDG&E to isolate the customer’s inverter from the electric distribution system.  Removal of the revenue meter (due to an emergency or maintenance on SDG&E’s system) will result in loss of electrical service to the customer’s facility or residence for the duration of time that work is actively in progress.

SDG&E recommends that customers installing an inverter-based generator consider also installing an AC disconnect switch to facilitate maintenance of the customer’s equipment (i.e. inverter, PV arrays, etc) without the need for interrupting service to the customer.  The AC disconnect switch provides the additional benefit of allowing SDG&E to isolate the customer’s generator from the utility’s Distribution System without having to interrupt service to the customer’s facility or residence but for customers with 30 kW or smaller systems, it is optional.

SDG&E’s AC disconnect requirement for Distributed Energy Resources (Distributed Generation) will continue to apply to:

Inverter-based interconnections having a transformer-rated meter (i.e., all meter panels or switchboards employing the use of potential and current transformers).

Non-inverter based generators, including rotating or machine-based generators – regardless if the service meter configuration is transformer-rated or self-contained.

A description of the specific inverter(s) used to control the interconnection between SDG&E and the Generating Facility, including rating, brand name, and model number.  CEC-certified inverters1 will pass the requirements for Simplified Interconnection per SDG&E’s Electric Rule 21. Non-certified units will require further study and may involve additional costs.

A complete description of the generating equipment that the Customer plans to install.  If the Generating Facility includes photovoltaic panels, the description must include the manufacturer name, model number, number of panels, and the nameplate rating. If the Generating Facility includes a wind turbine, the description must include the manufacturer name, model number, number of turbines, and the nameplate rating. Only CEC-certified inverters and certified wind-turbine generators without separate inverters will pass the requirements for Simplified Interconnection.

More information about inverters and modules can be found at Go Solar California**.

A description of how the power output from the inverter is connected to the main service panel via a branch breaker.  The ampere rating of this branch breaker and the main service panel breaker must be compatible with the output rating of the Generating Facility.  The output rating is computed based on the total nameplate rating of the inverter.

If such metering is required, a complete description of the performance (generation output) meter and related equipment. The description must include the meter manufacturer, model number and type (socket or panel), as well as any other relevant information (e.g., socket, panels, breakers).  If instrument transformers are required, the description should include this information.