History of Gas Choice and Definitions

California gas industry restructuring began in 1988, when the California Public Utilities Commission (CPUC) issued the first of many rate design changes in an effort to open the natural gas market to competition.

The first change separated the California gas market into core and noncore customer segments, depending on the customer's load, end-use priority, and economic ability to use alternative fuels.

The noncore customers were provided with the ability to elect natural gas service from a Gas Service Provider (GSP) instead of the utility. The utility still provides these customers with the transportation of the gas across its distribution system to the customer's meter.

In 1991 additional rate design changes were implemented. One of those changes gives core customers the ability to elect commodity services from GSPs through a Core Aggregation Transportation (CAT) program. Other significant changes have been implemented which opened interstate pipeline capacity and gas storage services to competition.

The road to gas industry restructuring has not reached its end. We anticipate continued rate design changes to occur in order for the CPUC to reach its ultimate goal of providing all gas customers with a greater competitive gas marketplace.

Current definition of gas customer segments


Core Customers

Core customers include all residential, regardless of load size, commercial customers with annual loads below 250,000 therms, and those commercial customers with annual loads above 250,000 therms who elect to receive the higher reliability associated with core service.

Noncore Customers

Noncore customers include all cogeneration, regardless of load size, and those commercial customers with annual loads above 250,000 therms. 250,000 therms are approximately equal to an annual monthly average usage level of 20,800 therms.

To Become A Participating Gas Service Provider

Please send your questions to ESPADMIN@semprautilities.com.