The exemption that needs nothing from you
Solar energy systems and their components are exempt from the Connecticut sales and use tax of 6.35 percent under CGS Section 12-412. There is no application and no form.
Because it is automatic, the way it surfaces is as an absence. The tax simply should not appear in your quoted price, which means the only way to check it is to look for something that is not there.
On a system in the twenty to thirty thousand dollar range, 6.35 percent is well over a thousand dollars, so it is worth thirty seconds of checking rather than an assumption.
Ask directly whether the quoted price includes any Connecticut sales tax. If it does, ask why, and get the answer before you compare that quote against another one that handled the exemption correctly.
The exemption you can lose by not filing
Connecticut exempts the value a residential solar energy system adds to your property from local property tax under CGS Section 12-81. Adding a solar system should not raise your assessment.
Unlike the sales tax exemption, this one is not always automatic. Some municipalities require the homeowner to file an exemption application with the local assessor, and the requirement varies by town rather than being uniform statewide.
That variation is exactly why it gets missed. A homeowner who has read that Connecticut exempts solar from property tax may reasonably assume nothing is required of them, and a filing deadline can pass without anyone mentioning it.
Call your own assessor, ask what filing your town requires and by what date, and put the answer in your calendar. This takes one phone call and protects an exemption that runs for as long as you own the system.
What ending the federal credit changed here
The 30 percent federal Residential Clean Energy Credit under Section 25D expired for property placed in service after December 31, 2025. A cash or loan purchase now receives no federal tax credit at all.
Section 48E, the commercial credit, survives at 30 percent and is available to third-party owners under leases and power purchase agreements. The provider claims it, and whether any of that value reaches you depends on the rate you are offered rather than on any rule.
That is why third-party ownership is being promoted harder in 2026 than before. It is worth evaluating rather than dismissing, but it should be evaluated as a rate, not as a credit you receive.
Ask for the side-by-side: a cash purchase with no federal credit against the lease or power purchase agreement rate on the same system, over the same term, with the RRES tariff and the Solar Energy Adjustment treated identically in both.
Costing it out with the adjustment applied
Strike the federal residential credit from any quote that shows it, since Section 25D expired for property placed in service after December 31, 2025.
Rebuild from the 20-year RRES contract on the Netting or Buy-All tariff, with the Solar Energy Adjustment at $0.0402 per kWh of total generation for 2026 Netting enrollees, and the income-eligible adder if your household is at or below 60 percent of State Median Income.
Add Energy Storage Solutions if a battery is in the design, at $30 per kWh on enrollment plus 10 years of performance pay, and add both tax exemptions, remembering that the property tax one may require a filing with your assessor.
Then add the electricity you stop buying at roughly 27.4 cents per kWh, which remains the largest single term in the calculation. Ask for that version in writing.