The Power Grid

Energy connects us – even more so, through the electric power grid. The electric energy we all use needs to be reliable and to achieve that, our grid must be too. The regional grid provides exceptional value to all energy consumers because the investment to build and maintain it is cost-shared across a wide geographic region. That’s where ATC comes in. We work behind the scenes to provide a reliable pathway for power – operating the power grid, all day every day and in the process…energizing your future.

how it works


The electric power you use every day flows through a three-part system – generation, transmission and distribution. Power plants, solar fields, wind farms and other sources generate electricity that flows through high-voltage power lines over long distances to substations where the voltage is lowered. The power then flows over smaller, local wires known as distribution lines to homes and businesses.

Electricity is generated at various utility-owned power plants and independent power producers. The origin of that power comes from any of three basic generation sources.

Fossil Fuels
Natural Gas
Nuclear Fussion

The vital link between power production and power usage, ATC’s high-voltage power lines carry electricity over long distances from where it is generated to communities where it is needed.


Electicity from high-voltage power lines is reduced to lower voltages at substations. The power then flows over smaller, lower-voltage wires known as distribution lines to homes and businesses.

the role of MISO

Every minute of every day, 45 million people depend on MISO (Midcontinent Independent System Operator) to generate and transmit just the right amount of electricity – reliably, dependably, and cost-effectively. MISO operates as an independent, not-for-profit, member-based organization headquartered in Indiana that focuses on three critical tasks:


Reliably managing the flow of high-voltage electricity across 15 U.S. states and the Canadian province of Manitoba


Facilitating one of the world’s largest energy markets with more than $40 billion in annual transactions


Planning the grid of the future

MISO Membership

All or portions of 15 US states are located within the MISO region. These include: Arkansas, Illinois, Indiana, Iowa, Kentucky, Louisiana, Michigan, Minnesota, Mississippi, Missouri, Montana, North Dakota, South Dakota, Texas and Wisconsin.

Courtesy of MISO
How ATC works with MISO

Our utility customers and other organizations across the Upper Midwest are pursuing new energy policy goals that are affecting changes to generation sources. We work directly with MISO to determine the viability, planning and design interconnections for renewable generation projects being proposed across the Upper Midwest and within our service area. Our planning and engineering experts collaborate with utility customers to develop efficiencies and use technologies that interconnect these new resources, helping strengthen the grid during this energy transition.

ATC and the Grid

As a federally and state-regulated utility, we are experts at what we do. We own, build, operate and maintain the regional power grid in portions of Wisconsin, Minnesota, Illinois and the Upper Peninsula of Michigan. Every minute of every day, we keep the power flowing for over 5 million energy consumers. The safe and reliable operation of our system and energy of our people contribute to the vital connection between where power is generated and where it is needed.

Service Area
Benefits of electric reliability
A reliable grid is essential to maintaining a safe and healthy society, allowing the public seamless access to the power needed in our communities
Electric reliability delivers significant economic benefits by providing access to the most cost-effective energy available and limiting interruptions to this vital service
A stable and reliable grid enables the efficient transition to a more sustainable renewable energy future

The energy transition is upon us: fossil fuel generation is declining​ and low-carbon generation alternatives are increasing. Buildings and vehicles are becoming electrified and severe weather events continue to cause stress on the power grid. Throughout these changes, our electric energy needs to remain reliable. How the grid is built today – using innovative solutions for grid improvements like battery storage and other emerging technologies​-ensures exceptional reliability for tomorrow.

The winds of change

Our energy landscape is rapidly evolving, driven largely by public policy goals set by organizations, communities, utilities and governments. These changes are affecting the regional MISO grid as generation shifts from legacy fossil-fuel plants to intermittent renewable resources, electrification and climate change. This transformation is placing stress on the electric grid and driving the need for new infrastructure to move power from where it’s generated to areas where it’s needed.

To connect new resources to the grid, a stronger, more robust electric grid is required. To get there, ATC and other transmission-owning utilities are connecting all forms of generation with upgraded and new infrastructure that improves the stability of the regional grid – ensuring all energy consumers continue to have safe and reliable electric power.

ATC Service Area: Delivered Energy Sources
Natural Gas
Carbon Neutral (Nuclear)