See: www.azsolarcenter.com/ benefits/solarsalestax.html
Yes. Arizona provides a sales tax exemption for the sale or installation of "solar energy devices". A solar energy retailer may exclude from tax up to $5,000 from the sale of each solar energy device, and a solar energy contractor may exclude up to $5,000 of income derived from a contract to provide and install a solar energy device. For contractors, the deduction cap of $5,000 applies to the contract, rather than each energy device. To take advantage of these exemptions, a retailer or contractor must register with the Arizona Department of Revenue (ADOR) filing Arizona Department of Revenue Form 6015 - Solar Energy Devices.
Go to www.solar-estimate.org