According to the US Energy Information Administration’s (EIA), a relatively small number of investor-owned power utilities (168 distribution companies, i.e. 5.7% of the 2,938 power utilities operating in the United States) supplied 71% of all electricity customers in 2017 (110 millions out of 154 million customers). These investor-owned utitilies tend to be very large (on average nearly 655,000 customers) and are prevalent in heavily populated areas on the East and West coast. The two largest ones are located in California, namely Pacific Gas and Electric (PGE) with 5.48 million customers and Southern California Edison Company with 5.07 million customers.
Publicly-owned utilities - power distribution companies owned by federal, state, and municipal owners - are the most numerous (1,958) and supply 24 million customers (on average 12,100 customers each). The largest ones are the state-owned Puerto Rico Electric Power Authority (PREPA) with 1.47 million customers, and the municipality-owned Los Angeles Department of Water and Power with 1.43 million customers. Finally, 812 cooperatives (not-for-profit member-owned utilities) are mostly located in the Midwest and Southeast, serving 20 million customers (on average 24,500 customers each).