The proposal calls for 30 percent of the state's power to come from sources such as wind and solar by 2025. It would build upon a state law adopted last year that requires 10 percent of the state's power to come from renewable sources by 2015.
Democrats say expanding the standard would improve the market for alternative energy companies that Michigan is wooing to diversify its economy.
Utilities also would be required to help customers decrease electricity usage.
Republicans who run the Senate likely won't even consider the proposal until Michigan resolves its budget problems for the fiscal year that starts in October.