(35 ILCS 200/10-5)
    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; and
        (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.
        (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; and
            (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. 100-781, eff. 8-10-18.)