(2) The acceptance of any indebtedness at the election to determine the question of annexation shall not include any indebtedness except such as has been incurred or assumed on account of development or purchase of a utility, including the replacement value of the unreimbursed investment of an investor owned utility in energy efficiency measures and installations within the annexed area. [Amended by 1991 c.358 §3; 2003 c.802 §72]