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What developers need to know about connecting to our system

If you are a large or small power producer and would like to connect to Great River Energy’s transmission system, you are required to follow our interconnection guidelines and:

  • Use “good engineering practices”, as specified by NERC
  • Fund a System Impact Study
  • Fund a Transmission Service Request Study
View Great River Energy’s generation interconnection guidelines  »
View Great River Energy’s Tie-Line and Substation Interconnection Guideline  »
View Great River Energy’s Transmission Load Connection Risk Management Policy »

Federal Energy Regulatory Commission (FERC) rules require electric utilities to treat all electric transmission users in a comparable manner, including other utilities and non-utility users of the transmission system, such as wind generation developers.

In Minnesota, the Midcontinent Independent System Operator (MISO) supervises the connection of new equipment and use of the transmission network. MISO reviews proposed connections to determine if they meet established criteria. Interconnections to the transmission system must go through the MISO interconnection process. Information can be found here.

Good engineering practices must be followed

All users of the electric transmission system must follow “good engineering practices” in order to connect and use the system for:

These criteria are required by the North American Electric Reliability Corporation (NERC). Most of the criteria were developed following past electrical system blackouts – the most notorious of which was the 1965 Northeast Blackout, which affected the New York and New England area. The organization that was formed following that blackout is now known as NERC.

Two studies must be completed

Before any new generation source can be connected to the transmission system, two separate studies must be completed:

The developer is responsible for:

Before a study can be started, a request must be made to put the project into MISO’s queue, or line-up of projects. (Transmission utilities maintain queues in order to monitor the connection and approval process, and keep track of requests for system connections and transmission service.) A developer may request to be entered into the generator queue for the System Impact Study or the appropriate Open Access Same-time Information System for the Transmission Service Request. Or, requests can be made to enter both queues simultaneously.

Results of the study must be made available to the public after they are completed. Generally, these studies are posted on company Web sites or on the MAPP Web site.

System Impact Study

The System Impact Study (SIS) report contains information about the electrical interconnection and how it is used. The electrical interconnection consists of the physical equipment such as wires, switches, transformers, meters, etc. The type and design of the equipment must meet the criteria. This is important both for the protection of the party connecting to the electric system as well as the other transmission users.

The SIS report also analyzes whether the appropriate equipment is being used and whether it can withstand the maximum short-circuits and current flow at the connection point. The impact that the new generation has on nearby electrical equipment (adjacent substations) also is reviewed. In some cases, equipment at the adjacent substation may have to be replaced and this cost would be included in the report.

Preparing the SIS report can take months or years depending on the size and complexity of the generation equipment that will be connected. The study must include the impacts of all generators that have a higher queue ranking. A SIS report for wind generators of 2 MW to 20 MW typically takes about three to six months to prepare. Completion of the SIS report does not guarantee that the new connection will be accepted since it may take some time for additional transmission equipment to be installed.

After the SIS report is completed, it must be reviewed and approved by the transmission owner and receive approval from the Midwest ISO.

Transmission Service Request Study

A Transmission Service Request (TSR) study must be approved before a wind generator can use the electric transmission system. This study evaluates the impact of sending power from the generator to the load. Due to the parallel flow nature of the electric transmission system, restrictions (criteria violations) that prevent a TSR study from being approved may not be near the generator or the load. Transmission service cannot be granted until the restrictions are removed, usually by upgrading or expanding a transmission system.

Transmission owners are obligated to upgrade their system to accommodate the transmission service request within their capability to do so. This process involves planning for upgrading existing facilities or constructing new facilities, acquiring regulatory permits and receiving approval by various MISO transmission committees. In some cases, the transmission owner may not receive all necessary approvals and cannot provide the transmission service.

The owner of the new generation source may have to pay the costs of upgrading or installing new equipment.

How to start the process

Contact a local electric supplier to determine which transmission utility’s system you will need to connect. NOTE: all transmission line owners are required to provide a good faith effort to accommodate generation connection requests.

If you need to connect to Great River Energy’s system, e-mail wind@grenergy.com or call 763-445-5099. Ask about:

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