Special Assessment for Solar Energy Systems

Illinois allows solar energy systems to be assessed for property tax at a reduced value—either the value with a conventional system or with solar, whichever is lower. To qualify, file the State of Illinois PTAX-330 form with your county assessor's office; eligible systems include both active and passive solar for water heating, space heating, and photovoltaics, though equipment that serves non-solar purposes (like structural or aesthetic components) does not qualify.

You can market to residential and commercial customers that solar installations may receive favorable property tax treatment under this program. Inform clients that the assessment compares the property value with conventional versus solar systems and uses the lower figure, potentially reducing their tax burden; they must file PTAX-330 with their county assessor, and note that commercial systems generating power for wholesale/retail sale do not qualify in counties with populations under 3,000,000.

This property tax incentive uses alternate valuation methodology: county assessors determine two values (conventional and solar-equipped) and apply the lesser for assessment purposes. Residential solar systems of all types (photovoltaic, water heat, space heat) are eligible statewide; commercial systems generating electricity for sale qualify only in counties exceeding 3,000,000 residents. Administration occurs at the county level through PTAX-330 filings, with no apparent state-level funding mechanism described in the materials.