Average Cost per watt:
$3.15 per watt
Written by
Andy Sendy
As of 2024, the average cost of solar panels in Illinois is $3.15 per watt, making a typical 7.2 kilowatt (kW) solar system $15,876 after claiming the 30% federal solar tax credit now available.
This is higher than the average price of residential solar power systems across the United States, which is currently $3.03 per watt.
The size of a solar panel system also plays a role in how much the installation will cost.
Larger solar installations typically have a lower cost per watt because the panels can be purchased at a ‘bulk price.’ However, these larger solar systems will still have a higher total cost because they are made up of more individual panels.
System size | Avg cost per watt | Avg system cost (After tax credit) |
|---|---|---|
4 kW | $3.84 | $10,752 |
5 kW | $3.53 | $12,355 |
6 kW | $3.32 | $13,944 |
7 kW | $3.17 | $15,533 |
8 kW | $3.06 | $17,136 |
9 kW | $2.97 | $18,711 |
10 kW | $2.91 | $20,370 |
Read more: What is a kilowatt and a kilowatt-hour?
Solar installation costs will vary with your location and the size of your home's electricity bill. To be meaningful, solar cost information needs to be tailored to the individual's situation.
If you enter your details into the solar calculator below, you will get a solar cost and savings estimate and find out how much solar panels will cost for your home based on current offers from your local solar installation companies.
The cost of solar energy includes more than just the equipment and installation—it also includes permitting costs, inspection costs, and installer profit margins.
These different components are what make the price of solar fluctuate between installations. Some of the factors that affect solar power system installation costs for specific homes include:
Homes that use more electricity will need more solar panels to cover their energy needs.
Although solar panels do get cheaper on a per-watt basis, the overall cost of the system will increase as more panels are added.
However, the higher a home's energy usage, the more solar panels can save homeowners energy bills.
The price of solar panels can vary depending on the type of solar panels you choose.
There are two main types of solar panels for residential solar installations: monocrystalline and polycrystalline. Monocrystalline solar panels are more efficient and the most common type today.
Polycrystalline panels have a lower efficiency rating and a slightly lower price point, but they are rarely used for home solar. The type of inverter you buy will also influence the cost of your solar system.
You may see some solar quotes with prices that seem too good to be true.
If you get quoted ridiculously low prices, the installer might use low-quality equipment or an unsustainable pricing model. You want to use a solar installer that is charging enough so that they can stay in business - as you'll be relying on them for the next 25 years!
It's important to compare multiple solar quotes to ensure that your installer offers the best quality at the best price possible.
The overall cost of solar can be influenced by the solar incentives available.
Across the U.S., homeowners can apply for the federal solar tax credit. The solar tax credit makes installing solar more cost-effective by providing homeowners with a tax credit equal to 30% of the cost of their installed solar panel system.
Local solar tax incentives and rebates can save homeowners thousands on a solar installation, especially when combined with the federal solar tax credit.
Use our solar panel calculator to see what solar incentives are available in your area.
The federal solar investment tax credit supports the cost of installation of renewable energy systems in Illinois.
This tax credit is currently 30% of the value of the solar system, and it is claimed on your taxes in the year after installation.
Many people mistakenly call this tax credit the Illinois solar tax credit, but it is actually a federal tax credit.
Illinois itself does not offer a solar tax credit.
The table below shows the data extracted from a real-life quote delivered through the SolarReviews marketplace recently for a fairly typical home in Illinois.
As you can see, the payback period is relatively short and equates to a much better return on investment than the historical returns available from investing in things like shares or property.
System information | Value |
|---|---|
System Size | 7.3 kW |
Est. Power Generation | 10,048 kWh |
Payback Time | 9.4 years |
Gross Cost | $22,995 |
Net Cost after Solar Tax Credit | $16,096 |
Total Value of Avoided Utility Costs Over 25 Years | $57,382 |
The most important difference between buying solar panels and any other purchase is that solar panels last 25 to 30 years. This is a long time, and you will need customer service over all that time.
We recommend you find a small or mid-size, local, family-owned solar company. These companies tend to care more about you and your specific job. You don't want to be on hold with a corporation's call center for the next 25 years!
Andy Sendy is a well-known and trusted figure within the solar industry with more than 15 years of experience.
His video reviews of the leading brands of solar panels and home energy storage batteries are a must-watch each year for both homeowners and solar industry professionals alike.
In 2021, an article he wrote about a clause i...
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