It also says the state had the lowest rates in the region several years ago. The study has been prepared for release Friday by the Wisconsin Citizens Utility Board and Wisconsin Coalition of Energy Consumers, using federal data.
It links rate increases to the higher cost of natural gas and expenses for the state's power grid and nuclear plants. It says the state's Public Service Commission has granted investor-owned utilities higher rates of return than those permitted in most other states.
The typical Wisconsin residential customer paid $64.50 a month for electricity last year. That's an increase of 25 percent since 1997.
The typical Illinois residential customer paid a $1.50 less each month than Wisconsin customers, and a Missouri customer, $12 less.
The report doesn't include rate increases in recent weeks by Wisconsin utilities.
A Public Service Commission spokesperson says the report is "oversimplistic" and inconsistent.