35 ILCS 200/10-5
2021 Illinois Compiled Statutes|Chapter 35 - REVENUE|35 ILCS 200/ - Property Tax Code.|Title 3 - Valuation and Assessment

Sec. 10-5. Solar energy systems; definitions. It is the policy of this  State that the use of solar energy systems should be encouraged because they  conserve nonrenewable resources, reduce pollution and promote the health and  well-being of the people of this State, and should be valued in relation to  these benefits.(a) "Solar energy" means radiant energy received from  the sun at wave lengths suitable for heat transfer, photosynthetic use,  or photovoltaic use.(b) "Solar collector" means(1) An assembly, structure, or design, including     passive elements, used for gathering, concentrating, or absorbing direct and indirect solar energy, specially designed for holding a substantial amount of useful thermal energy and to transfer that energy to a gas, solid, or liquid or to use that energy directly; or(2) A mechanism that absorbs solar energy and     converts it into electricity; or(3) A mechanism or process used for gathering solar     energy through wind or thermal gradients; or(4) A component used to transfer thermal energy to a     gas, solid, or liquid, or to convert it into electricity.(c) "Solar storage mechanism" means equipment or elements (such as  piping and transfer mechanisms, containers, heat exchangers, or controls  thereof, and gases, solids, liquids, or combinations thereof) that are  utilized for storing solar energy, gathered by a solar collector, for  subsequent use.(d) "Solar energy system" means(1)(A) A complete assembly, structure, or design of     solar collector, or a solar storage mechanism, which uses solar energy for generating electricity that is primarily consumed on the property on which the solar energy system resides, or for heating or cooling gases, solids, liquids, or other materials for the primary benefit of the property on which the solar energy system resides;(B) The design, materials, or elements of a system     and its maintenance, operation, and labor components, and the necessary components, if any, of supplemental conventional energy systems designed or constructed to interface with a solar energy system;(C) Any legal, financial, or institutional orders,     certificates, or mechanisms, including easements, leases, and agreements, required to ensure continued access to solar energy, its source, or its use in a solar energy system, and including monitoring and educational elements of a demonstration project; or(D)  Photovoltaic electricity generation systems     subject to power purchase agreements or leases for solar energy between a third-party owner, an operator, or both, and an end user of electricity, where such systems are located on the end user of electricity's side of the electric meter and which primarily are used to offset the electricity load of the end user behind whose electric meter the system is connected.  A system primarily is used to offset the electricity load of the end user of electricity if the system is estimated to produce 110% or fewer kilowatt-hours of electricity than consumed by the end user of electricity at such meter in the last 12 full months prior to the system being placed in service.(2) "Solar energy system" does not include:(A) Distribution equipment that is equally usable         in a conventional energy system except for those components of the equipment that are necessary for meeting the requirements of efficient solar energy utilization;(B) Components of a solar energy system that         serve structural, insulating, protective, shading, aesthetic, or other non-solar energy utilization purposes, as defined in the regulations of the Department of Commerce and Economic Opportunity; or(C) A commercial solar energy system, as defined         by this Code, in counties with fewer than 3,000,000 inhabitants.(3) The solar energy system shall conform to the     standards for those systems established by regulation of the Department of Commerce and Economic Opportunity. (Source: P.A. 102-662, eff. 9-15-21.)