Interconnection through Detroit Edison (DTE) and Consumers Energy (CMS)

Interconnection is a process of using an energy generating system to produce electricity, which is then used residentially or transferred to the electrical power grid. This electricity can be generated from a number of sources, such as: biomass or agricultural digesters, energy storage devices, fuel cells, industrial gas turbines, internal combustion engines, micro turbines, solar/photovoltaic devices, stirling engines, and wind turbine generators. The electricity is either used by the utility customer responsible for its generation, or sold to a utility such as Consumers Energy (CMS) or Detroit Edison (DTE), known as customer generation or distributed generation.

The Michigan Public Service Commission (PSC) first adopted interconnection standards for distributed generation in September 2004 but they were revised under PA 295 due to customer and utility dissatisfaction with the previous rules. These standards provide for 5 levels of interconnection with cutoffs at 30 kilowatts (kW), 150 kW, 750 kW, and 2 megawatts (MW). Consumers Energy and DTE both have standardized interconnection procedures which also must comply with all local, state, and federal regulations. All installations must also comply with the Michigan Public Service Commission's Electric Interconnection Standards detailed in R 460.601- R 460.656.

Customers of Consumers Energy and DTE wishing to interconnect are responsible for the coordination of the design, installation (or contracting of a qualified installer), operation, and maintenance of a system, as well as the compliance with all regulations. The utility companies are responsible for providing a primary contact or representative to assist customers who interconnect.

Though Consumers Energy and Detroit Edison both have distinct interconnection processes, the general interconnection process for both major utility companies (CMS and DTE) is comprised of these general steps:

1. Starting the Interconnection Process: Customers should notify the utility of their wish to interconnect an electrical generating system. The utility will then provide the required application materials. It will also be necessary for the applicant to choose the best applicable rate for the system. If selecting net metering, this should be indicated on the interconnection application to determine eligibility. Net metering allows retail electric utility customers who generate a portion of their own retail electricity to be billed only for their net energy use during each billing period. For CMS and DTE, the net metering application is included on the general interconnection application.

• For DTE, these application materials can be found here. (link to website)
• For CMS, these application materials can be found here. (download Word document)

2. Completing the Interconnection Application and Application Review: After completing and submitting the interconnection application with the appropriate filing fee, it will be reviewed. Applicants will be notified by the utility within 10 days. If approved, an Engineering Review may be required. If the application is denied, the utility will provide an explanation of the deficiencies of the application. If it is found that an Engineering Review is necessary for an approved application, the parties will be required to execute an Engineering Review Agreement to determine if a Distribution Study is required.

3. Engineering Review and Distribution Study: The Engineering Review determines whether a Distribution Study will be required to determine the impact of the customer's project on the utility's electric distribution system, and if there are modifications that need to be made to the generation project. Before an Engineering Review is performed, an agreement must be executed. If a Distribution study is needed, a Distribution Study Agreement also will be needed, allowing the utility to make the necessary system modifications and upgrades in order to approve the interconnection application and proceed with installation of the system. These system modifications may come at a cost to the system owner, in which case the applicant may choose at this time whether or not to proceed with the project. *After the Engineering Review and Distribution Study have been completed (if was determined these steps are necessary), Consumers Energy requires that an applicant state in writing their intent to pay any costs identified in the Distribution Study, and to proceed with the design and construction of the energy system. CMS interconnection applicants will then submit a completed Commissioning Test Report, which will approve or deny the project for interconnection. If the project is approved, a written statement of final approval, final cost reconciliation and a Generator Interconnection Operating Agreement (GIOA)/Contact List will be provided. (This GIOA is also known as the DTE Parallel Operating Agreement.) If not approved, corrective actions will be recommended.

4. Parallel Operating Agreement and Site Verification: DTE interconnection customers will receive a Parallel Operating Agreement (POA) (Consumers Energy refers to this document as the Generator Interconnection Operating Agreement), which covers contractual issues such as design, testing, maintenance, operation, modification of facilities, rate information, defaults, remedies, and liability. Customers will also receive a checklist to be submitted to the utility company along with the POA and proof of a city/township electrical inspection. Upon receipt of these documents, and after the system has been installed, a DTE Energy representative will then perform the customer generation site verification for inspection, testing and approval. Verification by DTE may include testing various operational tasks such as anti-island testing, changing meters, verification of proper installation of the isolation device, and verification of electrical city/township electrical inspection. After authorization of either the POA or GIOA, parallel operation of the energy system may begin.

For more detailed and company-specific interconnection requirements please visit:

Consumers Energy Customer Generation Overview
Consumers Energy Technical Interconnection Requirements
DTE Interconnection Process
DTE Detailed Interconnection Requirements