IOWA CITY — Iowa’s largest utility MidAmerican Energy has proposed some reductions to “right-size” the company’s energy-efficiency programs and provide a savings to customers.However, consumer advocate representatives and some in the energy efficiency workforce have expressed concern that MidAmerican’s proposal could make it more difficult for customers to take part in such programs.In MidAmerican’s proposed Energy Efficiency filing for 2019-2023, which was submitted last fall to the Iowa Utilities Board, one of the more notable proposals includes the elimination of on-site assessments for energy rebate programs.