California Code, Public Utilities Code - PUC § 366

(a) The commission shall take actions as needed to facilitate direct transactions between electricity suppliers and end-use customers. Customers shall be entitled to aggregate their electrical loads on a voluntary basis, provided that each customer does so by a positive written declaration. If no positive declaration is made by a customer, that customer shall continue to be served by the existing electrical corporation or its successor in interest, except aggregation by community choice aggregators, accomplished pursuant to Section 366.2.

(b) Aggregation of customer electrical load shall be authorized by the commission for all customer classes, including, but not limited, to small commercial or residential customers. Aggregation may be accomplished by private market aggregators, special districts, or on any other basis made available by market opportunities and agreeable by positive written declaration by individual consumers, except aggregation by community choice aggregators, which shall be accomplished pursuant to Section 366.2.