When it began gas restructuring in 1988, the California Public Utilities Commission (CPUC) divided gas utility customers into two classes: core and noncore. The classification was designed to separate the natural gas industry’s competitive functions (gas procurement for customers participating in competitive markets, interstate and high pressure in-state transportation, and gas storage) from utility functions of local gas transportation and gas procurement for non-competitive customers. Dividing customers into service classes was a means of determining which customers were eligible to participate in the competitive markets.
Customers considered to be core customers are those who lack alternatives to utility gas supply or choose to not participate in competitive supply markets. Most core customers are residential or small commercial customers. Core customers are the highest priority for service during gas curtailments. Most core customers take bundled gas delivery and supply from their local distribution company (LDC), also called the gas utility. Most noncore customers receive unbundled service, meaning they purchase their gas supply from gas marketers or producers while continuing to have the gas delivered by the LDC.
Core customers in California do have the option to participate in third-party programs that combine, or aggregate, their gas loads so that they can buy their gas supply from non-utility suppliers. This program is called Core Aggregation, and the suppliers are marketers called Core Transport Agents.