The Iowa Utilities Board has approved a five-year plan for Interstate Light & Power’s energy efficiency plan. Board spokesman Rob Hillesland says the efficiency plans were first required of the state’s power companies in 1990. He says the plan puts into effect a program to help customers become more energy efficient and to save money and energy . Hillesland says the plan approved for Interstate has a variety options for increasing energy efficiency. He says it includes incentives like rebates for customers who install energy efficient air conditioners, washers and hot water heaters. He says the board has also asked Interstate to double its assistance to the low income winterization program. The winterization program helps low income Iowans install insulation and other improvements to make their homes more energy efficient. Hillesland says there was another goal in the Interstate plan.He says it will help lessen the impact of the recent rate increases by allowing customers to use less energy and save more on their bills. Interstate is a subsidiary of Alliant energy and has over 600-thousand gas and electric customers in Iowa.