Michigan voters will be asked next month to change the constitution to set new standards for renewable energy in the state.
Supporters of Proposal 3 say it will reduce the cost of utility bills.
Opponents say the plan would have an estimated cost of $12 billion.
As worded, Proposal 3 would require that by the year 2025, electric utilities would provide at least 25 percent of their annual retail sales of electricity from renewable sources, including wind, solar, biomass and hydropower.
The proposal would limit to not more than 1 percent per year electricity utility rate increases to consumers to achieve compliance with the renewable energy standard.
Proposal 3 would also allow annual deadline extensions, requiring the Michigan legislature to enact laws encouraging the use of Michigan-made equipment and hiring Michigan residents to make it.
Supporter Diane Byrum represents the group Michigan Energy and Michigan Jobs.
"This is the opportunity for Michiganders to vote on their energy future. It's about good jobs," Byrum said.
Opponent Megan Brown of the group Care Michigan said Michigan would be the only state with this kind of law in its constitution.
"For us, this isn't about whether to support a clean environment of a green future for Michigan. This is about the process in which we get there and we are opposed to injecting energy policy into the state's constitution," Brown said.
Opponents say funding for ads in support of Proposal 3 are coming from a California environmental group.
Supporters say if the opponents are worried about funding of ads, they are not paying attention to the real issue.
The latest Local 4/Detroit News poll shows 39 percent of Michigan voters support Proposal 3; 44 percent are opposed to it; 15 percent remain undecided.