Review of NGSS and Recent FAQs about PG&E Storage Inventory

Date: January 19, 2023

As previously published, the 2019 Gas Transmission and Storage (GT&S) Rate Case Final Decision (D.) 19-09-025, issued on September 23, 2019, adopted the Natural Gas Storage Strategy (NGSS) that substantially restructured PG&E’s gas storage asset holdings Modified Firm Storage Rights - Effective April 1, 2020 | Pipeline ( and PG&E California Gas Transmission’s role in the market and operational functions. With the NGSS implementation, PG&E refocused its storage assets on system reliability.


Effective April 1, 2020, the PG&E firm storage services are shown in the table below:



Storage ServicesInjection Capacity (MMcf/d)Inventory Capacity (bcf)Withdrawal Capacity (MMcf/d)
Core Firm Service*214243251210*307
Inventory Management (Balancing)752004575300
Reserve Capacity (New)025010250


*PG&E Storage Withdrawal – January 15


As part of the NGSS, the Commission adopted PG&E’s reclassification of storage gas with the restructuring of PG&E’s gas storage asset holdings. PG&E reclassified 51 Bcf of PG&E-owned gas in storage from “working gas” to “base gas” in June 2021 as previously published in our news article. Overall, the current PG&E’s total gas inventory (working gas and base gas) in storage is about 124 Bcf.


Recently, there have been frequently asked questions about the 51 Bcf reclassified gas and PG&E’s storage operations:


Q. Does PG&E remain confident in its ability to provide reliable service this winter with the current PG&E Storage Inventory?


A. PG&E remains confident in its ability to provide service this winter period. PG&E has sufficient capacity to meet all firm core and balancing withdrawal obligations.


Q: Does the 51 Bcf of reclassified working gas still physically remain in PG&E’s storage fields?


A: Yes, the 51 Bcf remains in PG&E’s storage fields.


Q: If the base gas is still physically in the ground today, is it possible to withdraw it?


A. Yes, PG&E can withdraw it for operational purposes.


Q: How was the reclassified 51 Bcf used prior to the NGSS implementation?


A. Historically, majority of the gas was effectively used as base gas.


Q: Is there another source of information on the reclassification of the 51 Bcf?


A: Yes, as posted on the EIA:


Please call Allen DeBrum at 415.706.3960 if you have questions.