Midcontinent Independent System Operator

The Midcontinent Independent System Operator, Inc., formerly named Midwest Independent Transmission System Operator, Inc. (MISO)[4] is an Independent System Operator (ISO) and Regional Transmission Organization (RTO) providing open-access transmission service and monitoring the high-voltage transmission system in the Midwest United States and Manitoba, Canada and a southern United States region which includes much of Arkansas, Mississippi, and Louisiana. MISO also operates one of the world's largest real-time energy markets.[5][6] The 15 states covered by MISO are: Arkansas, Illinois, Indiana, Iowa, Kentucky, Louisiana, Michigan, Minnesota, Mississippi, Missouri, Montana, North Dakota, South Dakota, Texas, and Wisconsin.[7]

Midcontinent Independent System Operator
TypeNonprofit organization
Legal status501(c)(4)[1]
HeadquartersCarmel, Indiana, U.S.
Coordinates39°58′00″N 86°08′37″W / 39.966715°N 86.143745°W / 39.966715; -86.143745Coordinates: 39°58′00″N 86°08′37″W / 39.966715°N 86.143745°W / 39.966715; -86.143745
ServicesIndependent System Operator; Regional Transmission Organization
John R. Bear[2]
Phyllis E. Currie[3]
Revenue (2018)
Expenses (2018)$400,001,689[1]
Employees (2018)
MISO Reliability Footprint

Definition of ISOs and RTOsEdit

Both ISOs and RTOs are organizations formed with the approval of the Federal Energy Regulatory Commission (FERC) to coordinate, control and monitor the use of the electric transmission system by utilities, generators and marketers. An ISO is a non-profit organization that combines the transmission facilities of several transmission owners into a single transmission system to move energy over long distances at a single lower price than the combined charges of each utility that may be located between the buyer and seller. The ISO provides non-discriminatory service and must be independent of the transmission owners and the customers who use its system.[8]

RTOs also provide non-discriminatory access to the transmission network; however, they are required to meet specific FERC regulations that deal with transmission planning and expansion for an entire region, the use of energy markets to deal with system congestion, of power users and owners. RTOs offer regional wholesale electric transmission services under one tariff.[8]

FERC first required transmission owners to provide non-discriminatory access to their lines in Order Nos. 888 and 889, building on the model it had used to require interstate natural gas pipelines to provide access to pipeline capacity. In those orders, FERC noted that ISOs could provide the additional assurance of independence from the owners and eliminate multiple ("pancaked") rates to transmit electricity over long distances. Shortly after that, FERC Order No. 2000 encouraged the formation of RTO's to regionally manage portions of North America's electricity grid.[9]

There are nine ISOs, five of which are RTOs, operating in North America. They manage the systems that serve two-thirds of the customers in the U.S. and over half the population of Canada.[9] Over time, the distinction between ISOs and RTOs in the United States has become insignificant. Both organizations provide similar transmission services under a single tariff at a single rate, and they operate energy markets within their footprints.[9]

Incorporation under FERCEdit

MISO was established in 1998 as an ISO and was approved as the nation's first RTO by FERC in 2001. The organization is headquartered in Carmel, Indiana with operation control centers in Carmel and Eagan, Minnesota and Little Rock, Arkansas.[10]


MISO is an independent and member-based non-profit organization. Its members include 51 transmission owners with more than 65,800 miles of transmission lines. Members include investor-owned utilities, public power utilities, and cooperatives, such as: Entergy, AES Indiana, International Transmission Company, Great River Energy, Xcel Energy, and City Water Light and Power.[11]


MISO began its operation on "Day 1", a development phase between 1998 and 2005. Throughout this period, the company initiated and built up transmission services to increase grid reliability. MISO was established as an ISO in 1998 after voluntary discussions led to its formation. One year later, the first board of directors was elected. By the end of 2000, the organization had more than 70 employees. In 2001, FERC approved MISO as the nation's first RTO.[12]

In 2005, MISO announced the opening of the MISO Energy Markets. The new services ushered in MISO's "Day 2" development phase, providing a wholesale electricity market that settles $2 billion in transactions each month. During this period, MISO grew its employee base to more than 600 staff, and moved the corporate headquarters and operations center under one roof in Carmel, Indiana.[12]

In addition to Day-Ahead and Real-Time markets, MISO operates an ancillary services market that began on January 6, 2009. This market provides energy and operating reserves and regulation and response services supporting reliable transmission services.[12]

The name was changed in April 2013.


MISO is governed by an independent ten-member Board of Directors, consisting of nine independent directors elected by the membership, and the president of MISO.[13] No board member may have been a director, officer, or employee of a member, user, or affiliate of a member or user for two years before or after the election to the Board. Under MISO's Standards of Conduct, all MISO board members, employees, and their immediate family members must divest themselves of any financial holdings in member or user companies.[14]

In 2018, MISO employed a staff of 1,096 employees[1] between its three operation control centers and its transmission planning office in Metairie, Louisiana.


MISO uses a computer model called a State Estimator that analyzes real-time conditions of the MISO power grid. The system has been in operation since December 31, 2003. It serves as the primary management tool for the reliability of transmission facilities throughout the organization's footprint. The State Estimator is one of the world's largest computer systems and provides 303,800 data points that are updated every 5 seconds.[15]


As the primary RTO in the Midwest and South United States, MISO carries out operational responsibilities to maintain energy flow.

Grid management and reliabilityEdit

Data is evaluated by Reliability Coordinators and Reliability Analysts, monitoring the grid 24/7. Projecting power movement in real-time, MISO's control room staff monitors and manages activity on the electric transmission system.

Infrastructure planning and energy alternativesEdit

MISO performs regional planning in accordance with FERC principles. MISO infrastructure planning has four primary objectives:

  • provide an efficient and reliable transmission system
  • access a diverse number of energy resources, including renewable energies
  • expand energy trading opportunities
  • meet state and federal energy policy objectives [16]

MISO MarketsEdit

This open market began on April 1, 2005, and provides financially binding day-ahead and real-time energy pricing. MISO Markets include a Financial Transmission Rights Market, a Day-Ahead Market, a Real-Time Market, and a market for operating reserves and regulation. They are operated and settled separately, providing a clear look at day-to-day price changes.[17]

Planning effortsEdit

MISO Transmission Expansion Plan (MTEP)Edit

MTEP is a long-term annual planning study that identifies and supports the development of transmission infrastructure that is sufficiently robust to meet local and regional reliability standards and enables competition among wholesale energy suppliers. The MISO Board of Directors reviews the MTEP annually during its December meeting. MTEP includes recommendations for transmission infrastructure additions and electric grid improvements throughout the MISO footprint. Since its inception in 2003, MTEP plans have recommended almost $6.9 billion in transmission projects, totaling $2.2 billion already in operation. Page text.[18]

MISO – PJM Interconnection Joint and Common Market (JCM)Edit

In cooperation with PJM Interconnection (PJM), the two organizations developed a Joint and Common Market (JCM) to align market rules between them and to reduce the operating impact of the many transmission interconnections between the two RTOs. In December 2003, the two RTOs filed a Joint Operating Agreement with FERC, detailing how the organizations will share information and phase in their respective operations.[19]


  1. ^ a b c d e f "Form 990: Return of Organization Exempt from Tax". Midcontinent Independent System Operator Inc. Internal Revenue Service. December 31, 2018.
  2. ^ "John R. Bear". Midcontinent Independent System Operator. Retrieved November 11, 2020.
  3. ^ "Phyllis E. Currie". Midcontinent Independent System Operator. Retrieved November 11, 2020.
  4. ^ url=https://www.misoenergy.org/AboutUs/MediaCenter/pages/MediaCenter.aspx%7Cformat=https |accessdate =2013-07-03
  5. ^ "MIDO". api.misoenergy.org. Retrieved 2019-01-10.
  6. ^ "What We Do" (https). Retrieved 2009-02-24.
  7. ^ https://brookfieldrenewableus.com/wp-content/uploads/2020/05/Market_Information_MISO_0-1.pdf
  8. ^ a b "FERC". Retrieved 2009-02-24.
  9. ^ a b c "IRC Sourcebook" (PDF). Archived from the original (PDF) on 2011-07-26. Retrieved 2009-02-24.
  10. ^ "MISO Locations".
  11. ^ "MISO Fact Sheet".
  12. ^ a b c "History" (https). Midcontinent Independent System Operator. Retrieved February 24, 2009.
  13. ^ "Board of Directors". Midcontinent Independent System Operator. Retrieved November 11, 2020.
  14. ^ "Careers". Midcontinent Independent System Operator. Retrieved February 24, 2009.
  15. ^ "Improved State Estimator Gives MISO Most Comprehensive View of Power Grid" (pdf). Midwest Independent Transmission System Operator. 2004-01-15. Retrieved 2009-02-24.
  16. ^ "Archived copy". Archived from the original on 2015-09-25. Retrieved 2015-09-25.{{cite web}}: CS1 maint: archived copy as title (link)
  17. ^ "Archived copy". Archived from the original on 2015-09-25. Retrieved 2015-09-25.{{cite web}}: CS1 maint: archived copy as title (link)
  18. ^ MISO Transmission Expansion Plan
  19. ^ "Midwest Independent Transmission System Operator, Inc. and PJM Interconnection, L.L.C., Docket Nos. ER04-375-017, ER04-375-018" (PDF). Midwest ISO. 2006-10-26. Retrieved 2009-02-24.

External linksEdit