I'm in northern Illinois also and if I couldn't have done it myself it would not have been worthwhile. Your utility ComEd? At $0.15 per KWH takes to long to pay off in my opinion. How much is the cost per watt for the install? Just an FYI if you have solar you cannot apply for time-of-day pricing with Comed. Did they tell you how many RECs you'll get credit for over the 15 years?

In northern IL here too. In general solar performs poorly here primarily
because of the dominant cloudy skies. The first staying snow may put
your roof array out of business for the rest of the winter. I get around it
with over 100 panels, ground mounted so I can clear most snow. Just
now I can only run about 50%, because some ice froze on with the below
zero temps, and I need a better combination of sun and temp to get it off.

What is 1500 service? Are you just trying to reduce the electric bill, or
also take on some of the HVAC? The property here is 100% electric,
that required extensive use of heat pumps, chosen for very low minimum
temp capability and high SEER. These are variable speed inverter driven
technology, anything less should be high on the hit list. Depending on
capacity, the reversable heat pumps can take on some of the heating as
well as cooling. The energy budget here is about 28,000KWh a year,
depending on the severity of the winter.

The clothes dryer here is unvented, no heat blown outside. It does
use a heat pump, maybe not the most important feature. What I am
finding, is in winter clothes can quickly be dried by hanging in front of
one or more of my mini split heat pumps, helps keep the humidity up
too. May special racks for that purpose. Of course in summer clothes
go out under the sun.

The best approach is to itemize your energy needs, and see what can
be reduced. Match equipment to your needs. good luck, Bruce Roe

Start with "Solar Power Your Home for Dummies", a free online download.
Don't buy or commit to anything or talk to peddlers before you know more about what you're doing and the realities of residential energy generation and use that knowledge to see through what those with stuff to sell you will try to foist on you. Avoid big box and/or national retailers. Stay local. With some sharp negotiating you'll stand a better chance of a better price than the national outfits who are mostly bottom feeders anyway. And, you;ll have a higher probability of a better quality install.get a better quality install.

Get familiar with your utility rates for both gas and electric and their NEM particulars (if some form of NEM is offered) and the details of any REC program.

Abandoning gas appliances or gas as your primary energy source may/may not be a good idea.

Your research on rates NEM and RECs and their possible future direction can give some guidance.

After you read the Dummies book, Give your home an energy audit with the initial goal of learning annual usage.

Then, if saving money on energy bills is one goal of your exercise, consider conservation methods. Saving/not using energy is way more cost effective than buying or creating more of it. If you're really interested in the economics of PV, google "Solar Process Economics".

Natural gas as a heating method has been hard to beat on price per unit heat delivered in the past.

Know that you'll need some way to clear snow from an array if you expect to have winter energy production. Peddlers don't talk much about that.

Expect about 2.5 to maybe 3 miles/kWh for range mileage on an EV.

Welcome to the neighborhood.

Just an FYI this was the cloudiest January on record for the Chicagoland area. My output reflects that. I had 19 days of 5 KWHs or less per day of output from a 7.2KW size system. Just for reference today was mostly sunny and after clearing the snow in the morning I still made 26KWHs.

On the other side of the coin, when I lived in Buffalo, for the month of Feb. 1982, The Buffalo airport had more Global Horizontal Irradiance (G.H.I.) than San Diego.

Climate's what you expect. Weather's what you get.

My first advise to just about anyone who doesn't currently pay sky high electric rates is to only buy the system outright with cash or invest your money elsewhere. Too many other parties in the deal keep the majority of the benefits when you lease or take out a loan and you are stuck with a 20-25 year burden, especially if you ever move.

SunRun is the Costco Affiliate. If it was me, I wouldn't commit to anything. Continue your research and get additional quotes. You don't if you are going buy outright, borrow or lease. Buy outright is the way better solution with fewer strings attached. Real all warranty information.

I'm planning on buying outright.

My roof almost never has snow on it for long. It's over a tall hangar with lots of prevailing wind. We are NEM 1 currently. The salesman mentioned the adjustable block program and said those credits are built into the price to reach the minimum power requirement. Don't know how to quantify that. I'm pretty handy and know I can do the install but thought I might lose the 30% tax credit.
I'll start reading the dummies book.
Im not trying to do too much. Mostly just reduce my dependency on ComEd and eventually have a lower overall energy bill while helping the environment a little bit.

Thanks everyone.

Just remember knowledge is power. Have you seen this site and its links? Illinois Shines – Illinois Shines is a state-administered incentive program supporting the development of new solar energy generation in Illinois.

If you did the work yourself you'd still qualify for the federal 30% credit. Unless you have been through a US Dept of Labor apprenticeship program you would not be eligible for the adjustable block program if you do the work yourself. Currently you get $82.26 per REC or Million watthours you generate.
Run the PVWatts program for your system size to see what you generate yearly multiplied by 15 years to see how much he's "built in the price" or (look at it how much he's stealing from you).

Good luck

I would like to hear how you get REC funds in IL. No one has yet
shown me how to do that, I might do 30 Million watthours a year.
Bruce Roe

Here you go latest version pricing, qualifications, etc. 134 pages of how to get REC funds in Illinois.
Program Guidebook – Illinois Adjustable Block Program (illinoisabp.com)

Btw, ComEd is at 0.96

Northern Illinois presents challenges. Here in San Diego, it is a different story. Our system produced 8,046 kWh of electricity for 2022. The average cost of electricity in San Diego for 2022 was $0.37/kWh. Based on this information, our system produced $2,977.02 of electricity for the year ($284/mo). When you consider that our out-of-pocket expense for the system was $10,575 after the 30% Federal tax credit (.70 * $15,107), it is not unrealistic for our payback period to be around 3.5 years. So, we've earned around $4,500 in the 1.5 years since the system cost was recovered. Not a bad investment.