(30 ILCS 725/1.2) (from Ch. 96 1/2, par. 7303)
    Sec. 1.2. Definitions. As used in this Act:
    (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 or 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
    
a solar collector, or a solar storage mechanism, which uses solar energy for generating electricity or for heating or cooling gases, solids, liquids, or other materials;
        (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 such components of such equipment as are necessary for meeting the requirements of efficient solar energy utilization; and
            (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; and
            (c) Any facilities of a public utility used to
        
transmit or distribute gas or electricity.
    (e) "Solar Skyspace" means
        (1) The maximum three dimensional space extending
    
from a solar energy collector to all positions of the sun necessary for efficient use of the collector.
        (2) Where a solar energy system is used for heating
    
purposes only, "solar skyspace" means the maximum three dimensional space extending from a solar energy collector to all positions of the sun between 9 a.m. and 3 p.m. Local Apparent Time from September 22 through March 22 of each year.
        (3) Where a solar energy system is used for cooling
    
purposes only, "solar skyspace" means the maximum three dimensional space extending from a solar energy collector to all positions of the sun between 8 a.m. and 4 p.m. Local Apparent Time from March 23 through September 21.
    (f) "Solar skyspace easement" means
        (1) a right, whether or not stated in the form of a
    
restriction, easement, covenant, or condition, in any deed, will, or other instrument executed by or on behalf of any owner of land or solar skyspace or in any order of taking, appropriate to protect the solar skyspace of a solar collector at a particularly described location to forbid or limit any or all of the following where detrimental to access to solar energy.
            (a) structures on or above ground;
            (b) vegetation on or above the ground; or
            (c) other activity;
        (2) and which shall specifically describe a solar
    
skyspace in three dimensional terms in which the activity, structures, or vegetation are forbidden or limited or in which such an easement shall set performance criteria for adequate collection of solar energy at a particular location.
    (g) "Conventional Energy System" shall mean an energy system utilizing fossil fuel, nuclear or hydroelectric energy and the components of such system, including transmission lines, burners, furnaces, tanks, boilers, related controls, distribution systems, room or area units and other components.
    (h) "Supplemental Conventional Energy System" shall mean a conventional energy system utilized for providing energy in conjunction with a solar energy system that provides not less than ten percent of the energy for the particular end use. "Supplemental Conventional Energy System" does not include any facilities of a public utility used to produce, transmit, distribute or store gas or electricity.
    (i) "Joint Solar Energy System" shall mean a solar energy system that supplies energy for structures or processes on more than one lot or in more than one condominium unit or leasehold, but not to the general public and involving at least two owners or users.
    (j) "Unit of Local Government" shall mean county, municipality, township, special districts, including school districts, and units designated as units of local government by law, which exercise limited governmental powers.
    (k) "Department" means the Illinois Department of Commerce and Economic Opportunity or its successor agency.
    (l) "Public Energy Supplier" shall mean
        (1) A public utility as defined in an Act concerning
    
Public Utilities, approved June 29, 1921, as amended; or
        (2) A public utility that is owned or operated by any
    
political subdivision or municipal corporation of this State, or owned by such political subdivision or municipal corporation and operated by any of its lessees or operating agents; or
        (3) An electric cooperative as defined in Section
    
10.19 of An Act concerning Public Utilities, approved June 29, 1921, as amended.
    (m) "Energy Use Sites" shall mean sites where energy is or may be used or consumed for generating electricity or for heating or cooling gases, solids, liquids, or other materials and where solar energy may be used cost effectively, as defined in the regulations of the Department, consistent with the purposes of this Act.
(Source: P.A. 94-793, eff. 5-19-06.)