IL HB5890

Establishes a new property tax assessment framework for commercial energy storage systems in Illinois counties with fewer than 3,000,000 inhabitants, effective for assessment years 2024 through 2040.

Sets the fair cash value of commercial energy storage system improvements by subtracting physical depreciation from the trended real property cost basis calculated at $496 per kilowatt hour of rated capacity, with depreciation based on actual system age divided by 25 years but not reducing value below 30% of cost basis.

Exempts commercial energy storage systems from equalization factors applied by the Department of Revenue, boards of review, assessors, or county assessment officers.

Requires owners to commission a metes and bounds survey prepared by an Illinois-registered land surveyor describing the land occupied by the system and access routes, with the survey delivered to the county assessment officer and landowner to establish a separate parcel identification number for tax purposes.

Allows farmland previously assessed under Section 10-110 to return to farmland assessment after the energy storage system is removed, and permits taxing districts to abate taxes on commercial energy storage systems by majority vote of their governing authority.