Dive Brief:

• The MidContinent Independent System Operator (MISO) has taken control of the transmission systems of Entergy and nine other transmission owning companies, five other balancing authorities and 33 new market participants in Mississippi, Louisiana, Arkansas, Texas and Missouri.
• The new MISO South region includes: Entergy, Cleco Corp., Lafayette Utilities System, Louisiana Energy and Power Authority, Louisiana Generating, South Mississippi Electric Power Association and East Texas Electric Cooperative.
• With the move, MISO grows by about 40,000 MW to 196,000 MW.

Dive Insight:

The addition of MISO South expands the grid operator's transmission system by about 27%, but there is little free transmission capacity between the southern region and the MISO footprint in the north so moving excess generation between the region's will be limited.

The Southwest Power Pool (SPP) lost out on a potential expansion when Entergy and the other transmission owners decided to join MISO. However, after weighing their options, a portion of the Western Area Power Administration, Basin Electric Power Cooperative and Heartland Consumers Power District intend to join SPP instead of MISO.