In Arizona, several entities are authorized by various constitutional provisions and statutes to provide electrical services to customers. Two such entities are public service corporations and irrigation districts. The Arizona Constitution authorizes public service corporations, such as APS, to furnish electricity. Ariz. Const. art. XV, 2 and 3. APS is regulated by the Corporation Commission, which defines APS's area of service by issuing various certificates of public convenience and necessity. A.R.S. 40-281, 40-282. Other such entities include power districts, A.R.S. 48-1501 through 48-1619; electrical districts, A.R.S. 48-1701 through 48-1822; and agricultural improvement districts, A.R.S. 48-2301 through 48-2475.