IC 36-7-2-2
Planning and regulation of real property; access to solar energy

Sec. 2. A unit may plan for and regulate the use, improvement, and maintenance of real property and the location, condition, and maintenance of structures and other improvements. A unit may also regulate the platting and subdividing of real property and number the structures abutting public ways. In planning for and regulating the use of land or in regulating the platting or subdividing of real property, a unit may also regulate access to incident solar energy for all categories of land use.

IC 36-7-2-8
Solar energy systems; ordinances; reasonable restrictions

Sec. 8. (a) As used in this section, "solar energy system" means either of the following:
        (1) any solar collector or other solar energy device whose primary purpose is to provide for the collection, storage, and distribution of solar energy for space heating or cooling, or for water heating; or
        (2) any structural design feature of a building, whose primary purpose is to provide for the collection, storage, and distribution of energy for space heating or cooling, or for water heating.
    (b) A unit may not adopt any ordinance which has the effect of prohibiting or of unreasonably restricting the use of solar energy systems other than for the preservation or protection of the public health and safety.
    (c) This section does not apply to ordinances which impose reasonable restrictions on solar energy systems. However, it is the policy of this state to promote and encourage the use of solar energy systems and to remove obstacles to their use. Reasonable restrictions on solar energy systems are those restrictions which:
        (1) do not significantly increase the cost of the system or significantly decrease its efficiency; or
        (2) allow for an alternative system of comparable cost and efficiency.