Iowa has a sales tax exemption for the sale of solar energy equipment which is defined as “equipment that is primarily used to collect and convert incident solar radiation into thermal, mechanical, or electrical energy or equipment that is primarily used to transform such converted solar energy to a storage point or to a point of use.” This definition does not include supplies used for storage or safety of the equipment and it must collect, convert, or transmit solar energy. At least 50 percent of the equipment must be used for this purpose. (Iowa Department of Revenue, Iowa Sales and Use Tax Guide, updated November 18, 2021)