Your Guide to Solar Panels in Illinois: 7 Steps to Solar Panels in Illinois

The average Illinois homeowner pays off their solar panel system in just 12 years and continues to save on energy bills thereafter, with an average lifetime savings of over $16,500.

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Solar is a great investment in Illinois for most residents. The typical system is below average in size and more affordable than it would be in most other states, with the average cost of solar panels in IL coming in around $20,475. That number can dip below $14,000 after the federal and state incentives and rebates are considered.

In fact, Illinois made our list of the best states for solar tax credits and rebates

In addition to affordable solar solutions, the State of Illinois offers a variety of non-conventional financing options that make solar more accessible. Access to perks like net metering also helps to make panels more valuable over time.

In this guide, we’ll be discussing the entire solar conversion process from start to finish so that you know what to expect every step of the way. You can use the links below to skip to a specific section for more information.

Step 1: What to Consider When Buying Solar Panels

Step 2: Getting a Quote from a Solar Provider

Step 3: Signing a Solar Contract

Step 4: What to Expect on Solar Panel Installation Day

Step 5: Final Inspection for Installed Solar Panels

Step 6: Permission to Operate (PTO)

Step 7: Sit Back and Enjoy Your Solar Energy

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Best National Provider

Nationwide Service

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Average cost


  • Most efficient panels on the market
  • National coverage
  • Cradle to Cradle sustainability certification
  • Great warranty coverage


  • Expensive
  • Customer service varies by local dealer
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ADT Solar

Best Warranty Coverage

Regional Service

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  • Industry-leading warranty coverage
  • Expansive service area


  • Some reported communication issues
  • No leases or PPAs
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Sun Badger Solar

Outstanding Regional Installer

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  • Offers products from leading manufacturers
  • Competitive pricing
  • Offers rewards for customer referrals


  • No leases or PPAs
  • Relatively young company

Step 1: What to Consider When Buying Solar Panels in Illinois

There are a few important things to think about before you jump into getting solar quotes. We’ll explain some details we recommend considering early on in the process in the following sections.

Research If Solar Panels Are a Good Fit For You in Illinois

The Solar Energy Industries Association (SEIA) ranks Illinois 15th in the country for its rate of solar adoption, and with great energy savings, it’s not hard to see why it’s so popular here.1

While solar investment is worthwhile for most Illinoisans, that doesn’t necessarily mean it’s a good fit for you. Your first order of business should be to determine your specific property’s solar viability and the value photovoltaic (PV) panels could bring to your home.

We recommend starting by getting an idea of what system size you’ll need to offset your average monthly energy consumption. Our solar calculator is a great tool for this, as it takes into consideration your property’s sun exposure.

The average solar array size required in the Prairie State is 7.5 kilowatts (kW). If your estimated size is much larger than this, then you may have sun exposure issues from things like tree coverage that limit your production capabilities.

You might also want to consider the weather in your area, as panels generate less power on cloudy days. Illinois sees around 198 sunny days per year, but some cities see much less sunshine.2 If you live in an area with below-average sun exposure, your solar viability will be a bit lower.

Consider Net Metering

In many states, one of the most significant factors when considering how suitable your property is for solar adoption is access to net metering programs. Net metering — also called net energy metering or NEM for short — is a policy that requires your utility company to credit your energy bills for every kilowatt-hour (kWh) your panels overproduce and send to the electric grid.

NEM is mandated by the Illinois Public Utilities Commission (PUC) for all electricity providers in the state, including Ameren and Commonwealth Edison (ComEd). All power companies are not only required to offer NEM, but every kWh sent to the power grid is guaranteed to be credited with the full retail value. That means every kWh you send offsets one kWh you pull from the grid.

Thankfully, NEM isn’t a critical consideration when assessing how valuable panels will be throughout the state. However, it’s important to keep in mind that the policy is subject to change in the future.

The table below includes a quick look at how solar conversion costs and system values in Illinois compare to those throughout the rest of the country.

Illinois State Average United States National Average
Solar Power System Size Required 7.5 kW 9 kW
Typical Cost Per Watt to Install Photovoltaic (PV) Equipment $2.73 $2.66
Average Total System Cost Before Federal Solar Income Tax Credit $20,475 $23,940
Average Federal Solar Tax Credit Value $6,143 $7,182
Average Total System Cost After Federal Credit $14,333 $16,758
Average Panel Payback Period 12 years 12 years
Average Lifetime Savings of Converting to Solar $16,585 $22,379

Research How to Finance Solar Panels

After you decide that solar is a good option for your home, you can start looking into the different financing options for PV systems to see which suits you best.

First, you’ll need to know what system price you’ll need to afford. If you haven’t already, now is a good time to use our solar pricing calculator to see an estimate of what your system will total.

The average upfront cost for a solar system in IL is around $20,500 before state incentives and solar rebates. This number may intimidate you, but remember that solar arrays typically pay for themselves and save above and beyond their costs.

Once you have an estimate for your system, you can choose one of the payment options below:

  • Cash purchase: When you pay in cash, you’ll, of course, need to pay the entire price of your system at once. This is the least accessible option, but it does provide the highest energy savings. Without interest, your system will be the most affordable in the long run as well.
  • Solar loan: Solar loans make going solar much more accessible, as you’ll pay just a down payment — which can be as low as $0. The rest of the system cost is financed and paid over time, plus interest. The interest will reduce your long-term savings and make your effective system costs a bit higher.
  • Solar lease: A solar lease lets you rent your solar panels for a fixed monthly rate. You then get to use the generated renewable energy to offset or eliminate your electric bills. Since you never own your panels with a lease, your monthly payment will never be $0 (as it could with cash or a loan), so savings over time will be lower comparatively. Leases come with no upfront payment, so they’re accessible, but they don’t let you take the federal investment tax credit (ITC).
  • Power purchase agreement (PPA): PPAs are arrangements where an installer places panels on your home at no cost, and you agree to buy electricity generated by the panels instead of from your power company. This option saves the least over time and also precludes you from taking the ITC. However, PPAs are highly accessible thanks to not having any upfront payment.

The state offers the Illinois Solar for All (ILSFA) program, which is similar to a traditional solar loan. However, the Solar for All incentive program keeps interest rates and down payment requirements low to make solar conversion more accessible, and it requires that you work with an ILSFA-approved vendor for consumer protection.3 This program is also available for commercial customers and nonprofit organizations.

Illinois also provides access to community solar. Community solar is a great option for homeowners who want to support the renewable energy movement but either can’t afford panels or don’t want panels on their roofs.

A good rule of thumb to remember is that your savings will be higher and your renewable energy system costs will be lower with options that have a shorter panel payback period. As such, this is a good metric to use to decide on a payment option.

Step 2: Getting a Quote from a Solar Provider

After you get your budget and financing option squared away, you can start looking for a company to handle your PV project. We’ll explain what to look for and how to choose a reputable installation company in the sections below.

Picking a Solar Installer

Choosing an installation company seems like an easy task until you start researching companies, and then things can quickly become overwhelming. With over 70 installers operating in Illinois, there are a few things you can prioritize to narrow down your options, including the following:4

  • The installer should have positive customer reviews and few (if any) complaints filed with the Better Business Bureau (BBB).
  • The company should have at least five years of experience in the Illinois solar industry.
  • The provider should have installers on its team that hold certification from NABCEP (North American Board of Certified Energy Practitioners).
  • The installer should carry high-value equipment brands, maintain reasonable pricing and accept the financing option you’ve chosen.
  • The company should provide extensive warranty coverage.

Below is a list of our top six solar company recommendations in Illinois:

  • GRNE Solar — Regional installer
  • Windfree Solar — Local installer
  • Sun Badger Solar — Regional installer
  • StraightUp Solar — Regional installer
  • ADT Solar — National installer
  • SunPower — National installer

You can get more information about these companies and why we trust them in our guide to the best solar companies in IL.

What to Expect After Requesting a Quote

A day or two after you request a quote from a local installer, a representative from the company should reach out to you and schedule a consultation. If you opt for a virtual meeting, then you’ll also need to schedule an in-person roof inspection. If you choose an in-person meeting, both can usually be done at the same time.

In either case, you’ll need to provide a recent electric bill before the meeting, and you might need to answer some questions about what heating and cooling equipment and appliances in your home use electricity.

After the consultation and roof inspection, your solar project will move into the design phase, and the installer will come up with a system that meets your needs. The information about the system will be included in a formal solar proposal, and your sales rep should schedule another call with you to explain what’s in the proposal.

Among other things, the formal solar quote should contain the following:

  • The cost of your system before and after the federal tax credit and other tax incentives.
  • The size of your system in kW, as well as the average expected production in kWh.
  • Estimates for the panel payback period and your lifetime energy savings.
  • Schematics for where all of your equipment will be installed, including any add-on products.
  • Information about your warranty coverage.
  • Payment information, including when your payments are due.
  • An estimated timeline for the installation.
  • Information on fees for permits and inspections.

Getting a solar proposal from just one company takes some time, but we recommend going through this process with at least two or three companies. Having options allows you to compare and find the best value for your money.

Some installers will offer discounts or free add-on products — like electric vehicle (EV) chargers or energy storage options — to entice you to sign with them.

Consider Purchasing Solar Accessories

Since the federal tax credit can only be taken once, it’s a good idea to have all of your desired solar equipment included in your initial estimate and installation. That means you should think about add-on products you might want to be installed alongside your panels. Below are some of the more popular add-ons chosen by Illinoisans.

  • EV chargers: EVs are becoming quite popular throughout Illinois.5 Some solar customers looking for a convenient way to charge at home opt to have EV chargers installed alongside their panels.
  • Solar batteries: Solar batteries are most popular in areas where NEM isn’t available. While all Illinois homeowners have access to net energy metering, backup power is still great for maintaining electricity through power outages and for maintaining effective net metering if the current policy gets downgraded. This is unlikely for the time being, though, thanks to the Climate and Equitable Jobs Act establishing such an aggressive renewable portfolio standard (RPS) goal.
  • Energy efficiency upgrades: Monthly utility bills are slightly below average in the Prairie State, but efficiency upgrades are still popular because they further reduce energy costs. Improvements like new windows and doors, new insulation and solar water heaters are particularly popular, given the cold climate in the state.

We should mention that not all installers offer these add-on products. You might need to narrow down your potential providers based on your preferred add-on products.

Step 3: Signing a Solar Contract in Illinois

Once you determine the installer you’re going to work with for your home solar project, your next step is to sign the contract for the work. In the following sections, we’ll include some things you should look for in your contract and after signing to ensure you get favorable terms.

How Do Solar Warranties Work in Illinois?

Solar warranties offer coverage for a variety of things related to your system. Given the high cost of solar equipment, warranty coverage is one of the most crucial things to look for in your contract, in our opinion.

There are three different types of solar warranties, which we’ll briefly explain below.

  • Equipment warranties: Equipment warranties — sometimes called manufacturer warranties — cover defects in the equipment that can come about during the manufacturing process. The average equipment warranty length is 25 years.
  • Workmanship warranties: We recommend looking for a workmanship warranty that lasts at least 10 years, which is the industry average. These cover the labor involved in the installation process and help you avoid related problems. Some of the best labor warranties cover roof leaks, but most don’t.
  • Panel efficiency warranties: You should look for an efficiency or production warranty. This will guarantee that your panel efficiency won’t degrade rapidly. Most last for 20 years and guarantee at least 80% of the original panel efficiency after that time.

When Can I Expect Solar Service to Go Live?

Most Illinois residents should expect to wait between three and six months between the time they sign their solar contract and the day the system is activated. During that time, permits will be pulled, diagrams for connection to the grid will be created, equipment will be ordered to carry out your installation, the installation will be completed and your system will be connected to the grid.

You may experience installation delays for a few reasons:

  • Your installer may be backed up due to high demand.
  • Your permit approval may be delayed if your building department is backed up.
  • Your electric company might be behind with system inspections.

Of course, extreme weather — like tornadoes and severe thunderstorms — can also lead to installation delays.

Solar Panel Permits in Illinois

The State of Illinois doesn’t mandate building permits or electrical permits for PV system installations, but every municipality in the state locally governs permits and requires them for solar conversion.

No matter where you live, your PV panel installation company will submit all of the necessary paperwork to open permits. Permits typically come with an application and review fee that you’ll be responsible for paying. The cost should be included in your solar proposal.

Permit costs vary based on where you live. For example, the City of Chicago charges a flat fee of $275, and you can fill out an application online.6

The City of Aurora has a printable application, and it charges a permit fee based on the value of your system.7 Using the city’s permit fee calculator and the average solar array cost in the area, that permit will total around $600.8

Joliet charges a flat rate of $10 for every $1,000 worth of work completed.9 With the average system value sitting at just over $20,000 before incentives, that permit should cost around $200.

In most cases, your permits for your solar array installation will cost between $150 and $500, although there are outliers. If in doubt, you can always check your solar proposal for fee information or contact your installer or local building department for help.

Solar & Utility Interconnection

In addition to applying for building and electrical permits, your installation company should apply for interconnection. Interconnection is the policy that guides how your solar PV system interacts with the power grid, including how net energy metering is monitored.

Every utility company has a different process for applying for interconnection, but your solar provider should always be the one to apply. If there are application fees, those will be passed onto you.

Ameren has quite a lengthy interconnection agreement that requires information about your home and your system.10 The company charges a relatively high $300 for the application.11

ComEd uses an online application manager, which is more convenient. Based on ComEd’s website, the application process for level 1 interconnection — which applies to most residential solar power systems — takes just over 20 days to process and approve, and the application fee is $50.12

Despite the fees you’ll have to pay for the application and the time interconnection adds to your installation timeline, the process is well worth it. Interconnection is required to take advantage of net metering, so it will pay for itself time and time again.

Step 4: What to Expect on Solar Panel Installation Day in Illinois

Once permits and interconnection applications are approved, your clean energy installer can schedule the actual panel installation. Solar system installations in Illinois take between four and eight hours, on average. Most installers will be able to get the work done in a single day, but some may carry the job over into a second day.

Many solar customers wonder, “do I need to be home for solar panel installation?” You definitely should be home during the installation process. You’ll need to provide interior access to your electrical panel for the panel connection and any add-on installations.

Some solar companies will schedule the inspection with your utility company on the day of the installation, which is required before your system is activated. If that’s the case, you can expect your solar inspection to take an additional half hour or so.

Step 5: Final Inspection for Installed Solar Panels in Illinois

Upon the completion of your panel installation, your installer will schedule final inspections with your building department. The permits opened for the installation will remain open until the inspection is carried out. Open permits can prevent you from selling your home in some cases, and they can lead to violations, so closing them out is important.

If you only have panels installed, your building inspector may or may not be able to do an exterior inspection only, which won’t require you to be home. If an interior inspection is required — which is typically the case if you have add-on products installed inside your home — then you’ll have to meet the inspector to provide access.

Your solar provider should schedule the inspection for you, and this very rarely comes with a fee. If you miss your appointment, though, and end up needing a re-inspection, you might be charged for the inspector’s time.

After the building inspection, you’ll be responsible for making sure your system continues to function safely. Depending on the brand of panels and inverters you have installed, you might get access to a solar monitoring app. Your installer can set this up for you, and it will give you access to production and consumption information for your home.

Step 6: Permission to Operate (PTO) in Illinois

The last step before your installed panels can be activated is to get permission to operate (PTO) from your power company. An inspection of your system will be required before you get PTO. If your installer didn’t schedule the inspection on the day of installation, then they’ll get it on the calendar shortly after.

Once you get permission to operate, your solar provider should connect with you to explain how to turn on your system. Some of the more hands-on companies will come out to your property to show you. You should also confirm how to use the emergency shut-off for your system, and you can ask about solar monitoring if you haven’t already.

Going forward, you should keep the contact number of your installer handy in case you run into any problems and need to call on the warranty. You should also have the emergency number for your electric company. You can call that number after dialing 911 in case of an emergency.

We’ll include the numbers for the larger providers in the state below for easy reference:

  • Ameren: 1-800-755-5000
  • ComEd: 1-800-334-7661

Step 7: Sit Back and Enjoy Your Solar Energy in Illinois

Finally, you can relax and enjoy the perks your solar conversion is expected to bring you. You should see energy savings start to accrue and offset your installation costs, and you can also rest assured that your efforts have reduced your carbon footprint, your reliance on fossil fuels and your contribution to pollution.

You should also know that you’ll still likely see a return on investment (ROI) if you sell your home after converting. Going solar improves the value of your property, so you’re likely to see financial benefits no matter what you do after installation.

Find a Local Installer in Illinois

The SEIA (Solar Energy Industries Association) notes that there are nearly 100 solar installers serving customers in IL.13 Choosing the best one can take a lot of time, energy and research, but it’s one of the most crucial decisions you’ll make about your system.

Below, we’ll include links to ratings and rankings for the top solar installers in major cities in IL.

Village Hall in Addison, IL
Credit: WikiMedia / WikiMedia

Best Solar Providers in Addison

Downtown area in Arlington Heights
Credit: WikiMedia / WikiMedia

Best Solar Providers in Arlington Heights

Beautiful skyline of Chicago, IL
Credit: WikiMedia / WikiMedia

Best Solar Providers in Chicago

Aerial view of Naperville, IL
Credit: David Wilson / Flickr

Best Solar Providers in Naperville

View of Aurora from the water
Credit: Doug Kerr / Flickr

Best Solar Providers in Aurora

View of Main Street in Belleville
Credit: artistmac / Flickr

Best Solar Providers in Belleville

View of the Joliet skyline
Credit: WikiMedia / WikiMedia

Best Solar Providers in Joliet

Street view in Thornton, IL
Credit: WikiMedia / WikiMedia

Best Solar Providers in Thornton

Cook County and location of Worth, IL
Credit: WikiMedia / WikiMedia

Best Solar Providers in Worth

Cook County and the location of Wheeling, IL
Credit: WikiMedia / WikiMedia

Best Solar Providers in Wheeling

If you’re looking for larger statewide or regional solar companies, or you need an installer outside of one of the cities above, you can check out our guide to the best solar providers in Illinois.

FAQ: Solar Panels in Illinois

Below are some of the most common questions we get from Illinois residents about solar conversion, along with our responses.

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Article author
Dan Simms is an experienced writer with a passion for renewable energy. As a solar and EV advocate, much of his work has focused on the potential of solar power and deregulated energy, but he also writes on related topics, like real estate and economics. In his free time — when he's not checking his own home's solar production — he enjoys outdoor activities like hiking, mountain biking, skiing and rock climbing.
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Expert reviewer
Kristina Zagame is a journalist, editor and content writer with expertise in solar and other energy-related topics. Before joining EcoWatch, Kristina was a TV news reporter and producer, covering a wide variety of topics including West Coast wildfires and hurricane relief efforts. Kristina’s reporting has taken her all over the U.S., as well as to Puerto Rico and Chile.

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