(3) (c), every domestic corporation lawfully engaged in the business of producing, transmitting, delivering or furnishing heat, light, water or power to or for the public may acquire, for the purpose of developing power and generating energy for public use in the business:
(a) Any dam in or across any navigable waters of this state.
(b) All flowage and other rights and property necessary to the maintenance of any dam under par. (a).
(c) Any undeveloped water power or dam site upon any navigable waters within this state, except as provided under sub. (2).
(2) No award in any condemnation proceedings authorized by sub.
(1) shall be effective, and no corporation may purchase or otherwise acquire any property under sub.
(1) until it obtains from the commission a certificate that public convenience and necessity require the acquisition of the property, at the amount fixed by the award or agreed upon with the owner of the property.