Solar Companies in Illinois

Certasun is the highest-volume residential solar installer in Illinois, verified through Illinois Shines project application data. Headquartered in Buffalo Grove, they serve the entire Chicago metro and northern Illinois. Every aspect of the project — sales, design, permitting, installation, and incentive processing — is handled in-house with no subcontractors. They guarantee system production over its lifetime and process all Illinois Shines SREC payments and ComEd DG rebates on behalf of customers. Certasun also offers Prio, a prepaid solar service product designed for ComEd customers navigating post-ITC economics.

RxSun is a Chicago-founded, locally owned residential solar company consistently ranked among the top five Illinois installers on EnergySage. Known for competitive pricing, premium REC+Enphase systems, and an industry-leading 30-year SolarInsure™ warranty covering parts, labor, and roof penetrations with zero deductible. All installations are performed in-house by NABCEP-certified installers. RxSun handles full SREC and ComEd rebate processing on behalf of customers.

Windfree Solar is one of Chicago's oldest and most experienced solar installers, founded in 2009 with over 25MW of solar installed across residential, commercial, school, and municipal projects. They are NABCEP-credentialed, ICC-approved for both DG solar and EV charging, and are one of only two IPA-selected installers for the Solar Chicago low-income equity program. Best known for handling technically complex or custom projects that other installers pass on, and for deep SREC and incentive program expertise. Some project management inconsistencies noted in reviews for standard residential work.

SunSent Solar is a family-owned installer based in the St. Louis area, serving Central Illinois (Ameren territory) and Southern Illinois with some of the highest customer ratings of any installer in the state. Founded by family with deep contracting roots, SunSent performs all work in-house, backs every install with a lifetime labor warranty, and guarantees production — adding panels at no charge if the system underperforms. Particularly strong for ground-mount and agricultural installations, and well-versed in Ameren DG rebate and Illinois Shines SREC processing.

Ailey Solar is Chicago's only unionized residential solar contractor, founded by Jack Ailey and Dorian Breuer with the goal of bringing safe, affordable solar to all of Chicago. They are NABCEP-certified, ISEA members, and are one of only two IPA-approved installers selected for the Solar Chicago program, which provides low-cost solar to hundreds of Chicago residents. Ailey has notable commercial work including the Bronzeville Solar Pyramid and Fleet Fields in Lincoln Yards. A strong choice for customers who prioritize labor standards, equity program access, or Chicago-rooted community commitment.