Except as provided in section 7 of this chapter, a public utility may not begin the construction, purchase, or lease of any steam, water, or other facility for the generation of electricity to be directly or indirectly used for the furnishing of public utility service, even though the facility is for furnishing the service already being rendered, without first obtaining from the commission a certificate that public convenience and necessity requires, or will require, such construction, purchase, or lease.
IC 8-1-8.5-2