The regional cooperative that handles Entergy Corp.’s electricity transmission service has formed three new trading hubs in Louisiana, Texas and Arkansas.

The 15-state Midcontinent Independent System Operator’s new hubs will begin trading power on Dec. 19. The new hubs will join four existing Midwest trading hubs, making it easier to trade power and leading to more efficient commercial transactions among all participants, according to MISO.

Joining MISO is supposed to save Entergy customers $1.4 billion over 10 years, ensuring commercial and residential customers get the cheapest possible electricity.