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Customer-Owned Generation in WISCONSIN

Customer Owned Generation - Solar 2Wisconsin customers that want to install their own generation, and connect their power source to Alliant Energy’s electric grid or distribution system, need to follow a process called interconnection. The interconnection process includes the steps to obtain approval from Alliant Energy and emphasizes the safety of our customers and employees.

If you are installing your own generation with a capacity of up to 15 megawatts (MW), whether it is rooftop solar, a micro wind turbine or fuel cell to your home or business, you and your installer must follow the Public Service Commission of Wisconsin (PSCW) interconnection rules. In addition, you must meet all of Alliant Energy’s tariff requirements.

Customers are encouraged to check with Focus on Energy, Wisconsin’s utilities’ statewide program for energy efficiency and renewable energy, for potential grants and incentive available for Alliant Energy Wisconsin residential and business customers that are installing their own generation.

For customers interested in supporting renewable energy without investing in their own generation, learn more about Second Nature.

Your responsibilities

You and your installer are responsible for coordination of design, installation, operation and maintenance of any generation system you install, and for conforming to the requirements of our tariffs and rules, and applicable governmental laws and regulations (local, state, and federal).

These requirements are designed to protect distribution system facilities; avoid electrical interference problems; ensure the safety of customers, electric provider employees and the general public; and maintain overall system reliability.

You are required by law to maintain liability insurance (equal to or greater than the amounts indicated in PSC 119) or to prove financial responsibility by another means agreeable to us. You are required to notify us if a material modification is made to your generation facility at any time during or after the installation process. A material modification is any modification that changes the maximum electrical output of your facility or changes the interconnection equipment, including:

  • Changing from certified to non-certified devices
  • Replacing a component with a component of different functionality or UL listing

You also are responsible for the proper installation, operation and maintenance of the specified protective devices. Finally, you shall obtain, at your expense, any and all authorizations, permits and licenses required for the construction and operation of your generating facilities.

Our responsibilities

Alliant Energy is responsible for promptly carrying out the steps listed below and for meeting all required steps and timelines to process your interconnection application. We have designated the Renewable Hotline as the primary contact to assist you with any questions or information you need to complete your interconnection.

8:00 a.m. - 4:30 p.m., Monday - Friday

Alliant Energy Renewable Hotline
P.O. Box 351
Cedar Rapids, IA 52406-0351

Fax: 608-458-1155


The steps below are required by state law to interconnect to our distribution system. Links to actual state law and associated guidelines are included at the end of this page.

Step 1 - Notification

Call 1-800-972-5325 to inform us that you want to interconnect an electric generating system to our distribution system.

We respond to your request within 5 working days and provide all materials necessary to complete your interconnection application. All documents, forms and applications also are included in the last section of this page.

Step 2 - Interconnection application

Complete and submit the appropriate distributed resources application form per the links that follow, making sure all parts of the form are completely filled out.

  • Name and address under “Electric Services Distributed By” must be to the following on the Interconnection Application:

Wisconsin Power and Light Company
4902 North Biltmore Lane
Madison, WI 53718

The following required documentation will need to be included:

  • Interconnection Agreement and an application fee if applicable (Interconnection Agreement is optional at this point but will need to be completed before permission to operate is granted and generation can begin. If submitted up front with the Application it will speed up the approval and permission to operate process – please see step 12.)
    • Name and address under “Electric Services Distributed By” must be to the following on the Interconnection Agreement:
Wisconsin Power and Light Company
4902 North Biltmore Lane
Madison, WI 53718
  • Certificate of Insurance showing the appropriate liability insurance based on category.
    • Category 2 to 4 will need to name Wisconsin Power and Light Company with the address shown above as an additional insured party under Additional Interest, Certificate Holder, etc. on the Certificate of Insurance.
    • Category 2 to 4 will have to note “Certificate holder is named as an additional insured” in Description of Operation, Remarks, etc. on the Certificate of Insurance.
  • One-line diagram
  • Plot plan
  • Spec sheets for inverter
  • Spec sheets for solar panels/wind turbine
Please review and follow State of Wisconsin, Public Service Commission Chapter PSC119 guidelines. If any information is missing, it will be returned to you as incomplete.

Distributed Resources Application for Generation 20 kW or Less – PSCW form 6027 [PDF] 

Distributed Resources Application for Generation Greater than 20kW up to 15 MW –PSCW form 6028 [PDF]

Mail the completed application to:

Alliant Energy Renewable Hotline
PO Box 351
Cedar Rapids IA 52406-0351

Step 3 - Application review

Within 10 working days of receiving a new or revised application, we notify you whether the application is complete. If the application is incomplete, you will need to resubmit it with the needed corrections. We also will send you the appropriate standard interconnection agreement and surplus energy purchase power agreement, if applicable. Both must be signed by you and by us prior to commencing parallel generation.

Step 4 - Engineering review determination

When your application is complete, we determine whether an engineering review is needed. If an engineering review is necessary, we notify you within 10 working days and state the cost we will charge you for that review. Please consider utility input when specifying components to insure that your components will work on the Alliant Energy distribution system.
Note: If you are not notified about a review in 10 days, go to step 10.

Step 5 - Engineering review

After you notify us in writing to proceed and submit applicable payment, we will complete the engineering review and notify you of the results.

Step 6 - Distribution system study determination

If the engineering review determines that a distribution system study is necessary, we will include a written cost estimate in the review summary.

Step 7 - Completion of distribution system study

After you send us written notification to proceed and pay the applicable fee, we conduct the distribution system study. This study assesses the impact your generating system will have once connected to our grid. We provide you with the study results.

Step 8 - Notification of construction or modification costs

We notify you of distribution system study results and costs associated with any construction or modifications to our grid.
You provide a written agreement to pay for work related to the interconnection modifications.

Step 9 - Installation of customer generation

You submit payment for required upgrade of our distribution system. You install your generating equipment within a timeframe that is mutually agreed upon. You notify us when project construction is complete.

After we receive payment, we perform all work needed to upgrade our distribution system to accommodate your generating equipment.

Step 10 - System testing and acceptance

You are required to notify us of the completed installation and give us opportunity to witness or verify system testing. You also are required to provide us with any test results.
After we receive notification that an installation is complete, we do one (or more) of the following:

  • Witness commissioning tests
  • Perform an anti-islanding test or verify protective equipment settings at our expense Or
  • Waive our right, in writing, to witness or verify commissioning tests
  • Please note, you may be charged for testing, calibrating, and re-testing

Step 11 - Testing approval/rejection

We notify you of our approval or rejection of the interconnection. If approved, we provide a written statement of final acceptance and cost reconciliation. If we do not approve the interconnection, you may take corrective action and ask that we re-examine your interconnection request.

Step 12 - Interconnection agreement

After you receive an interconnection approval notice, the appropriate interconnection agreement must be signed by you and us before parallel generation operation commences. If it was not signed and included with the original application, please chose the appropriate form from the links that follow and mail to the address below.

Distributed Resources Interconnection Agreement for Generation 20 kW or Less – PSCW form 6029 [PDF]

Distributed Resources Interconnection Agreement for Generation Greater than 20kW up to 15 MW – PSCW form 6030 [PDF]

Mail the completed Interconnection agreement to:

Alliant Energy Renewable Hotline 
PO Box 351
Cedar Rapids, IA 52406-0351



Distributed Resources documentation

Distributed Resources Application for Generation 20 kW or Less – PSCW form 6027 [PDF]

Distributed Resources Application for Generation Greater than 20kW up to 15 MW –PSCW form 6028 [PDF]

Distributed Resources Interconnection Agreement for Generation 20 kW or Less – PSCW form 6029 [PDF]

Distributed Resources Interconnection Agreement for Generation Greater than 20kW up to 15 MW – PSCW form 6030 [PDF]

Distributed Resources Rate Form for Residential/Commercial Generation 20 kW or Less [PDF]

Rules and technical guidelines

Wisconsin Distributed Resources Interconnection Guidelines [PDF]
Helps explain PSC 119 and how these rules are expected to be implemented by utilities and customers. We recommend reading these rules and guidelines before beginning the interconnection process.

WPL Technical Guidelines for Interconnection of Parallel-Operated Generation Connected to the Distribution System [PDF]

Meter diagrams

Net Metered Self-Contained

General Service Instrument Metered with Self-Contained DG

Net Metered on Field Built

Duplex Manufactured Pedestal

Dual Instrument Transformer Rated

Tariff and power purchase information

Parallel Generation (In Excess of 20kW) - Sheet 7.75, Schedule PgS-1 [PDF]

Parallel Generation (20kW or less) - Sheet 7.80, Schedule PgS-3 [PDF]

Parallel Generation - Specifications - Sheet 7.90, Schedule PgS-4 [PDF]

Grants and incentives

Focus on Energy (Residential)

Focus on Energy (Business)

Rural Energy for America Program (REAP)

Wisconsin State Energy Office

For more information

Buy renewable energy (Alliant Energy’s Second Nature program)

Site assessment assistance (Focus on Energy)

A consumer’s guide: Get your power from the sun (U.S. Dept. of Energy)