Renewable energy: Customer owned generation (Iowa)

If you connect to our distribution system with a generation facility of up to 20 megawatts (MW) capacity, you and your installer must comply with Iowa Administrative Rules, Chapter 15 (IUC 199.15) and Chapter 45 (199.45) (click on Iowa Administrative Code (IAC), then scroll down to Utilities Division [199]).

In addition, you are responsible for following the interconnection rules of the Iowa Utilities Commission (IUC) and for meeting all Alliant Energy's tariff requirements.

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 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 [IAC 199.45] for Iowa customers, [PSC 199] for Wisconsin customers) 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 generation facilities.

We are responsible for promptly carrying out the steps listed below and for meeting all required steps and timelines to process your interconnection application.

To comply with the interconnection agreement, you must maintain general liability insurance coverage such as, but not limited to, homeowner’s insurance. Please attach proof of your insurance policy with your application.

Proof of insurance must include:

1. Facility address.
2. Interconnection customer as insured.
3. General liability coverage.

Use the following official Alliant Energy Iowa utility name and address on the Certificate of Insurance:

Interstate Power and Light Company
200 1st Street SE
Cedar Rapids, IA 52401

Please remit annually to:

Alliant Energy Renewable Hotline
GO-17
P.O. Box 351
Cedar Rapids, Iowa 52406-0351

We recommend reading these rules and guidelines before beginning the interconnection process.

• Iowa Administrative Code – Electric Interconnection of Distributed Resources Facilities Rule
• Alliant Energy DER Technical Interconnection Requirements.pdf
• Alliant Energy Definitions, Acronyms and Abbreviations.pdf
• Alliant Energy Electric Service Rules (includes meter and label diagrams) – Chapter 5, Distributed/Customer-Owned Generation .pdf
• Alliant Energy Electric Service Equipment Manual (includes meter equipment diagrams).pdf

This should provide you a general overview of the interconnection process. Each application is handled on a case-by-case basis and may include additional requirements not mentioned here.

Step 1 – Preapplication process/research

If you are interested in generating your own power, we recommend you read through our helpful information and watch the solar energy video series. This will give you some background information to see if self-generation is right for you and your home. If you decide to pursue installation, these documents will also help you ask the right questions as you search for a reputable installer.

Before you begin your project, gather your historical electrical usage data for your property. Installers require you to provide your electric usage history before giving you an estimate. To help expedite the process, you can find your usage history within My Account or add your installer as a guest user so they can easily have access for the remainder of your project. View our Account and Billing section and click on "Update My Account" within our Help Center.

Step 2 – Submit interconnection application

Once you find an installer, work with them to start your interconnection application with Alliant Energy. They should be able to guide you through the application process or even do it for you and only require you to read over the documents, sign them and provide the applicable fees. You should complete and submit a Standard Interconnection Request Application form (Level 1 or Level 2-4), proof of insurance (if required), other facility information (i.e., one-line diagram, plot plan, manufacturer's technical specifications and label information) from a nationally recognized testing laboratory. If any information is missing, the application will be returned as incomplete.

We recommend you and your installer use our Distributed Generation Assist tool to evaluate and refine your distributed generation system’s design. This tool provides guidance about location, size, design and equipment. You’ll get a downloadable summary report to help you avoid common issues our engineers often encounter reviewing interconnection applications.

If they do not do it for you, you can complete the online application and submit it through PowerClerk, our online portal, or mail it along with your application fee to:

Alliant Energy Renewable Hotline
GO-17
P.O. Box 351
Cedar Rapids IA 52406-0351

Please note: One-line diagrams must show the presence of a lockable visible disconnect and plot plans must show the location of the Alliant Energy meter in relation to the lockable visible disconnect; the disconnect should be adjacent to the Alliant Energy meter.

Step 3 – Application review

If the Standard Interconnection Request Application (Level 1 or Level 2-4) is incomplete or the fee is not received, Alliant Energy will notify you to resubmit.

If the application is complete, our Renewable Energy Hotline will notify you the application has been accepted. An Alliant Energy Distribution Engineer may contact you to explain the terms and conditions and to obtain any additional technical specifications, if required for your project. To stay updated on the status of your project, monitor the email you provided on the application (this is the email you gave to your installer).

Step 4 – Engineering review and approval

Our Distribution Engineering team will complete an engineering review to determine any changes to the distribution facilities or upgrades that are required to serve your generator. A feasibility study and an impact study may need to be completed.

We will notify you in writing with an estimate of the costs associated with any distribution facilities or upgrades required. You must notify us in writing (email is acceptable) to indicate acceptance of project terms and conditions. When additional investment in facilities is required, you must state your willingness to pay for the additional facilities. If you are not willing to pay for the required facilities, the interconnection request is then canceled.

Step 5 – Interconnection agreement

Our Renewable Hotline will complete the following documents and forward to you and your installer for your approval and signature:

• Applicable Standard Interconnection Agreement.
• Certificate of Completion.
• Attachment 2 of the Applicable Standard Interconnection Agreement (if applicable).
• Attachment 3, which details any necessary changes to distribution facility or upgrades (if applicable).
• Any other required documentation necessary for your project.

You return the following forms, via your installer, to our Renewable Energy Hotline:

• Signed Applicable Standard Interconnection Agreement.
• One signed original copy of the Certificate of Completion.
• Completed Attachment 2 of the Applicable Standard Interconnection Agreement (if applicable).
• One signed copy of the electrical inspection form.
• Payment for facility upgrades (if required).

Step 6 – Installation of customer generation

If required for your project, after we receive payment, we perform all work needed to upgrade our distribution system to accommodate your generating equipment.

You install your generating equipment within a timeframe that is mutually agreed upon. Please maintain ongoing communications regarding your project schedule and projected completion date with Alliant Energy personnel so that we may ensure proper interconnection with our facilities.

Before metering will be installed, you must provide documentation of a successful state electrical inspection. If required, a witness test conducted by an Alliant Energy Distribution Engineer will be completed. Special metering or reprogramming will then be installed.

Step 7 – Completion

You will be notified that the interconnection with IPL facilities is approved. A signed original Standard Interconnection Agreement and Certificate of Completion will be sent to you for your records. Your generating equipment should not be in operation prior to receiving this permission to operate.

Applications and processing times are classified by the size and type of system being installed. Remember if you’ve hired a solar contractor to perform your installation, the contractor will work with Alliant Energy on your behalf, so you must be in constant communication with your installer through every step. To stay updated on the status of your project, monitor the email you provided on the application.

Note: Numbers and types of technical reviews may vary by levels. To help expedite the process, complete and return necessary documents. If documents are incomplete or payment is not received, project duration may be delayed.

Billing

• Solar energy billing: Your questions answered.pdf
• Iowa inflow/outflow bill credit example
• Iowa inflow/outflow bill charge example
• Iowa inflow/outflow cash out example

Inflow Outflow – Current tariff (installations after 12/30/2020)

• Understanding our Inflow Outflow rate schedule.pdf
• Inflow-Outflow DG Billing (Sheet 42, Rate Code IO).pdf
• Understanding your Inflow Outflow bill – Residential.pdf
• Understanding your Inflow Outflow bill – General Service.pdf

Net metering pilot – Previous tariff (installations between 5/1/2017 - 12/29/2020)

• Understanding our net metering pilot.pdf
• Solar energy billing: Your net metering pilot questions answered.pdf

• Net Metering Pilot – Renewable Energy Facilities (FROZEN Sheet 39, Rate Code NM).pdf
• Alternative Energy & Small Hydro Production (FROZEN Sheet 52, Rate Code AEP).pdf
• General Rules and Regulations for AEP (Section 16).pdf
  
• Understanding your net metering pilot bill (sample).pdf

CSPP – previous tariff (must qualify, for systems up to 100 kW)

• Cogeneration & Small Power Production (Sheet 49, Rate Code CSPP).pdf
• General Rules and Regulations for CSPP (Section 16).pdf
• Understanding your CSPP bill (sample).pdf

Not every location is ideal for solar panels, nor is it always easy to install your own. Our community solar program was established to help make solar simple and accessible for everyone. For the vast majority of our customers, as an Alliant Energy customer, you can buy blocks of solar to cover up to 100% of your energy bill.

With the Alliant Energy® Community Solar program, Alliant Energy builds, owns, and maintains a dedicated solar site on behalf of the participating subscribers. The renewable energy produced by the solar site is delivered to the grid, where Alliant Energy manages the sale of the energy on the market. All the energy credit is then passed back to all participating subscribers for the life of the facility.

Learn more about how Alliant Energy Community Solar works and view frequently asked questions. 

An interconnection is an electric connection between a utility's energy grid and a customer-owned generation system that has the capacity to send energy to a utility's energy grid.

For safety reasons, generation systems that are interconnected to our power grid will not supply power to your home or business if an outage occurs. This protects your equipment from overloading and protects Alliant Energy personnel who may be working on electrical equipment in your area to restore power.

Your installer or certified electrician would need to install some form of transfer switch for when the power goes out. This switch must meet all of our Electric Service Rules to prevent any energy from back feeding into the grid during the outage.

Before you begin your project, you must gather the historical electrical usage data for your property. Installers require you to provide your electric usage history within My Account or add your installer as a guest user with limited access so they can easily obtain needed information for the remainder of your project. To add a guest user, follow the instructions found on the Update your information page. Note: Full access will allow a guest to make changes. View only access will only allow a guest to view your account information.

You can also call our Customer Service Center at 1-800-ALLIANT (800-255-4268) and request your usage history. To protect the privacy and security of our customers, only the account holder can request this information. Remember Alliant Energy will not provide this information to your solar contractor if they call us on your behalf.

The process could be delayed if required information is incomplete or missing, documents are unsigned or any required payments are not included. Remember, if you've hired a solar contractor to perform your installation, the installer will work with Alliant Energy on your behalf to submit the appropriate application and complete the interconnection process. Thus, you must remain in constant communication with your installer. To stay updated on the status of your project, monitor the email you provided on the application.

If you’ve attempted to contact them to resolve this in good faith, you may want to seek legal advice on the next steps and pursue legal action to resolve this third-party issue.

There are state resources to assist in resolving your issue. Please review the detailed information at the following website.

Iowa: https://www.iowaattorneygeneral.gov/

Wisconsin: https://www.doj.state.wi.us/dls/consumer-protection

Effective November 1, 2023

	(no change) synchronous der or legacy inverter	(new) modern inverter (UL 1741-sb)
Generation above 1/3 min load (shared feeder)	DTT required	DTT typically not required*
Generation below 1/3 min load	DTT typically not required	DTT typically not required
Dedicated feeder	DTT typically not required	DTT typically not required
Limited export	DTT typically not required	DTT typically not required

* Pending results of DER impact analysis performed during the System Impact Study (Iowa)/Distribution System Study (Wisconsin).

Note that DTT is not going away completely. DTT is still required for customers installing synchronous generators, and for legacy inverters whenever generation exceeds 1/3 minimum load on a shared feeder.

The terms distributed energy resources (DER) and distributed generation (DG) are used interchangeably.

The most common reason for limited hosting capacity of DER is voltage rise due to the interconnection of DER. Most inverter-based DER have a default setting of Constant PF mode set at unity. Implementing the voltage-reactive power (a.k.a. Volt-VAR) mode instead of the Constant PF mode allows more customers to interconnect to the grid and decreases the amount of review time an application will need by Alliant Energy.