Westar Energy is asking to raise the rates on residential and small business customers and lower the rates for large businesses.
Homeowners or small businesses would pay 6 to 9 percent more under Westar Energy's latest plan. Big businesses that buy lots of power would pay 6 to 15 percent less.
Westar officials say industrial users and other large-volume customers are paying more than their share.
The Citizens' Utility Ratepayer Board opposes the changes, saying it's unfair to raise rates on small customers to pay for millions of dollars of cuts for the big users.
The Kansas Corporation Commission will decide whether to grant or modify the company's proposal. The Westar proposal will have its first public hearing tonight.