The property tax exemption for qualifying renewable energy systems comes from N.J.S.A. 54:4-3.113a to g, and the annual exemption is the difference between the total assessed value of the property before and after the renewable energy system has been installed.
It is not applied for you. Form CRES, the Certification of Renewable Energy System, must be filed with your local municipal tax assessor, and the renewable energy system must be certified by the local construction code official. Two steps, two offices, and neither happens by default.
Ask your installer whether they assist with the filing, and whether the construction code official certification is something that falls out of the permitting and inspection process or is a separate request. Then put it on your own list regardless, because an exemption you qualified for and never claimed is money simply left behind.
Assemble what an assessor is likely to want while the project is fresh: the final installation invoice, the building permit and the inspection certificate. Requirements vary between municipalities, so a short call to your own assessor asking what they need is worth more than any general guidance, including this page.
Why this exemption is worth the paperwork
A solar system generally raises what a home is worth, and in a state with New Jersey property tax rates an increase in assessed value is not a trivial consequence. The exemption exists precisely so that improving your home this way does not come with an annual penalty attached.
Because it is an exemption rather than a payment, it is invisible. No cheque arrives, nothing appears on a statement, and there is no moment where you feel the benefit. That invisibility is exactly why people forget to file for it and why it rarely appears in a savings projection.
Add it to your own arithmetic even though no installer will hand it to you. Over the life of a system the avoided assessment is a real number, and it belongs alongside the bill savings and the incentive income rather than being left out because nobody quantified it.
It is also useful to a future buyer. Being able to show that the exemption is in place, alongside the permits and the interconnection paperwork, makes the system look like the maintained asset it is rather than an unknown quantity.
The sales tax exemption works differently
New Jersey also exempts solar energy equipment from state sales tax, but that one operates at the point of purchase rather than afterwards. Under N.J.A.C. 18:24-26.4 the purchaser must issue to the seller an Exempt Use Certificate, Form ST-4, or other approved form.
The certificate should indicate on its face that the purchase qualifies for exemption as a solar energy system, and the purchaser must insert the address of the property upon which the system will be installed. So it is tied to a specific property, not to you in general.
Ask your installer how this is handled and confirm the certificate has been issued rather than assuming the quoted price already accounts for it. It is a straightforward step, but it happens with the seller at the time of the transaction, and it is not something to sort out later.
Two exemptions, two entirely different procedures, at two different points in the project. Knowing which is which is most of the work, and putting both on a list at the start is the reliable way to end up with both.
Two exemptions, and only one of them happens by itself
New Jersey exempts solar energy equipment from state sales tax, but the exemption has a procedure. Under N.J.A.C. 18:24-26.4 the purchaser must issue to the seller an Exempt Use Certificate, Form ST-4, or other approved form. The certificate should indicate on its face that the purchase qualifies for exemption as a solar energy system, and the purchaser must insert the address of the property where the system will be installed.
Note that this happens at the point of purchase, with the seller, rather than being claimed back afterwards on a return. Ask your installer how they handle it and confirm the certificate has been issued rather than assuming the price you were quoted already reflects it.
The property tax exemption is separate and is not automatic either. Qualifying renewable energy systems are exempt from real property taxation under N.J.S.A. 54:4-3.113a to g, but Form CRES, the Certification of Renewable Energy System, must be filed with your local municipal tax assessor, and the system must be certified by the local construction code official.
The annual exemption is the difference between the total assessed value of the property before and after the system has been installed. Nobody files Form CRES on your behalf by default, so ask whether your installer assists, and put it on your own list either way. An exemption you qualified for and never claimed is the most avoidable cost in a New Jersey solar project.