Energy Storage
Energy storage represents one of the newer generator technologies in PG&E's service territory. Storage is considered a generator under Electric Rule 21 and is subject to interconnection procedures to ensure the safety and reliability of the electric system.
Qualifications
Energy storage generating facilities are not eligible for the Net Energy Metering (NEM) program, as the energy stored may not be from renewable sources. However, energy storage can be paired with a NEM system if applied for under NEM Multiple Tariff (NEMMT). See the information about interconnecting with one of the programs below.
Non-Export
As non-NEM eligible generators, energy storage may apply for Electric Rule 21 Non-Export, when installed in the following ways:
- Stand-alone generator
- With other non-exporting generators
NEM Multiple Tariff
Energy storage devices may be paired with NEM-eligible generators under the NEM Multiple Tariff, when:
- Storage devices are treated as non-NEM generators for purposes of fees and metering.
NOTE: If the energy storage device has a rated power output greater than 10 kW AC, the device may be no larger than 150 percent of the total rating of the respective NEM-eligible generators.
The items required in order for PG&E to issue written permission to operate a generating facility, which includes energy storage, are the same as detailed under the respective programs:
- Option S is a special rate modifier for customers with storage who are on B-19V, B-19 and B-20 rates. There is a 50MW cap on each rate schedule. Visit Option S cap tracker.
Visit Non-Export
Visit NEM-Multiple Tariff
How to apply
For storage under the Non-Export or NEMMT scenarios, the guidance for Non-Export and for NEMMT applies in full regarding documentation and timelines.
In addition, the below information should be included in the interconnection request.
NOTE: There is a storage section of the online application (form 79-974), which must be completed regarding the device's discharging (i.e. electrical source) function, the device's intended use and the device's charging (i.e. electrical load) function.
| Additional Item Requested | Purpose | |
|---|---|---|
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NEMMT Interconnection Documentation |
See Net Energy Metering Multiple Tariff (NEMMT) for all documents needed to apply. |
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Non-Export Interconnection Documentation |
Visit the Non-Export page for all documents needed to apply. |
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Description of Operations Documentation |
As energy storage devices interact with PG&E's system in complex ways, it is recommended to submit additional documentation to describe the operations of the facility to supplement the Application. |
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Customer-Owned Telemetry or PG&E Installed Telemetry |
Project’s with a net generation capacity of 1MW or greater require telemetry per section J.5 of the Rule 21 tariff. PG&E is now offering interconnection customers the option of using their own telemetry solution using one of PG&E’s approved device or aggregator vendors. More information can be found in our intro/FAQ document on the Distribution Interconnection Handbook page. |
Metering requirements
For storage device(s) with a total power rating greater than 10 kW AC, the Net Energy Metering Multiple Tariff (NEMMT) metering requirements are mandatory.
For storage device(s) with a total power rating of 10 kW or less, the NEMMT metering requirements are optional and not mandatory if the energy storage qualifies as an "addition" or "enhancement" as stated in the Qualifications section above. Instead, such facilities can choose to be subject to an estimation methodology for a NEM credit validation.
Costs and other considerations
Studies
For NEMMT Interconnection requests, including energy storage which qualifies as an "addition or enhancement" and meets the sizing conditions in the Qualifications section above, the Interconnection Request Fee, Supplemental Review Fee and Detailed Study Deposit do not apply.
For all other NEMMT and Non-Export Interconnection requests, including energy storage, the following cost considerations apply:
| Meter Type | Cost | |
|---|---|---|
|
$800 |
Interconnection Request Fee |
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$2,500 |
Supplemental Review Fee (if project fails Initial Review) |
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$10,000 |
Detailed Study Refundable Deposit (if project fails Supplemental Review or applies directly to Detailed Study) for generating facility 5MW or less |
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$50,000 plus $1,000 per MW of electrical output |
Detailed Study Refundable Deposit (if project fails Supplemental Review or applies directly to Detailed Study) for generating facility greater than 5MW |
Note: Upgrades to the electrical grid may be required, and a customer may be responsible to pay for the upgrade, depending on the type, in accordance with Electric Rule 21 Section E.4
For NEMMT Interconnection requests, including energy storage which qualifies as an "addition" or "enhancement" and meets the sizing conditions in the Qualifications section above, the same upgrade costs apply as a NEM-generating facility, as shown in Electric Rule 21, Section E.4.f (Table E.2)
Standby and Departing Load
PG&E has an interim policy for standby charges and departing loads for all energy storage. Standby charges and departing load charges will not apply to energy storage devices. Other generators located at the same generating facility may still be subject to standby charges as applicable.
Inspection and Testing
Energy storage generating facilities will be subject to final inspection by PG&E personnel. Non-Export interconnections that utilize non-export relays will require a pre-parallel inspection as described in the Transmission Interconnection Handbook Section G5.