Michigan Democratic Governor Gretchen Whitmer signed legislation on Tuesday mandating that 100% of energy in the state must come from renewable sources in the next two decades.

The new laws mandate that all electric providers in the state must reach 80% clean energy by 2035 and 100% clean energy by 2040. Renewable energy sources are defined by the laws as resources that naturally replenish “over a human, not a geological, time frame and that is ultimately derived from solar power, water power, or wind power.”

Whitmer said ahead of the bill signings that the new standards would “protect our air and water,” as well as include “the strongest labor standards in the country to create good-paying middle-class jobs.” She also noted “streamlined processes” to facilitate the creation of solar and wind energy, a reference to new zoning rules which shift powers away from local authorities and toward state regulators to accelerate the construction of new renewable energy facilities.

“With these bills, Michigan will lead the future of climate action,” Whitmer remarked. “We will protect our air, land, and lakes, and we will fight for future generations of Michiganders.”

Fossil fuels such as petroleum, natural gas, and coal are not counted as renewable by the laws. Nuclear energy, which does not create greenhouse gasses, is also not considered renewable.

Several other states, including California, Hawaii, Louisiana, Maryland, and New York, have passed similar laws requiring a complete shift toward green energy in the coming decades, according to an analysis from the Clean Energy States Alliance. Skeptics of policy goals to ban or discourage nonrenewable energy while pushing renewable sources observe a lack of green energy capacity, risks to electric grid reliability, and higher energy generation costs.