Interconnected Energy Grid

An electric grid is a large, interstate network of interconnected power generation plants, transmission lines, distribution networks and customers.

High-voltage transmission towers and power lines extending into the distance

MidAmerican’s electric delivery system is connected to a regional grid that’s managed by an independent entity called Midcontinent Independent System Operator, or MISO.

While MISO doesn’t own the power grid or facilities that are connected to it, MISO oversees and operates this power grid region, and it also administers the buying and selling of wholesale electricity through an interstate market. MISO’s regional footprint includes 15 states and the Canadian province of Manitoba. Its member utilities serve 42 million customers.

MISO service area includes parts of Arkansas, Illinois, Indiana, Iowa, Kentucky, Louisiana, Michigan, Minnesota, Mississippi, Missouri, Montana, North Dakota, South Dakota, Texas, and Wisconsin in the US and the Canadian province of Manitoba

MISO also manages approximately 65,000 miles of high-voltage transmission lines and works with members to build new or expand transmission systems across multiple states.

Since the regional power system is interconnected, all generating sources within it work together to serve the region – even those sources that are many miles or states apart. Power travels from generating sources to customers through big interstate electric superhighways called transmission lines.

If the system becomes unbalanced – that is, if customers throughout the region demand more power than the system can supply – MISO and its member utilities, including MidAmerican, must take steps to help MISO bring the grid back to a balanced energy demand and supply. Read about the steps we take to reduce demand and protect the grid.

MISO Multi-Value Projects

MISO members have completed most of the current transmission expansion plan, primarily designed to deliver reliability to the Midwest region and provide effective and efficient transmission solutions to meet expected growth in renewable energy generation. As part of MISO, MidAmerican assisted with the construction of four of the plan’s 17 transmission projects. MidAmerican’s portion of the project affected 12 Iowa counties and four Illinois counties.

In 2022, several transmission projects were approved by MISO and MidAmerican will assist in those construction projects as well.

As the grid operator, MISO must balance available generation supply and electricity demand throughout its multistate operating area in real time. All members are required to submit capacity projections, planned outages due to maintenance and other generation filings.