Once the pats on the back subsided Thursday, the people involved in crafting a law pushing Minnesota to the nation’s renewable-energy forefront took stock of the task ahead.

By the time today’s newborns reach adulthood, utilities must generate a quarter of the state’s electricity from sources like the wind, sun, running water and burned manure. Only about 5 percent of Minnesota’s present power would meet the standard.

If the entire burden fell to wind, for instance, it would mean 3,000 additional turbines jutting out of the Minnesota prairie.

Michael Noble, one of the law’s most vocal proponents, distilled it even further: “The total renewable energy output is going to be approximately the same as the energy being consumed by Minnesota households today — the amount of electricity being used by our refrigerators, our lights, our air conditioners and our furnace fans.”

“We’ve got to get cracking,” added Noble, executive director of Fresh Energy, a nonprofit environmental coalition.

Taking Minnesota’s renewable energy goal from the drawing board to the power grid won’t come easily or cheaply — it is likely to require billions of dollars in new equipment and miles upon miles of transmission lines. But state leaders described the power shift as vital.

“We have to break our addiction to fossil fuels,” Republican Gov. Tim Pawlenty said in signing the legislation. “It is detrimental to our national interests and our state interests on so many levels.”

The new law, which sailed through the Legislature, encourages the use of wind farms, small-scale hydroelectric dams and solar energy, as well as burned plants and animal waste.

Minnesota’s 25 percent by 2025 numerical goal trails targets already in place for Maine and New York, but those states had been getting a significant amount of electricity from large-scale hydropower facilities before their standards were adopted, according to data from the Interstate Renewable Energy Council and the Union of Concerned Scientists.

Minnesota depends on coal for almost half of the power produced in the state. Mike Bull, assistant commissioner for renewable energy at the Minnesota Department of Commerce, said wind, water and other renewible sources now account for about 5 percent.

Jeff Deyette, energy analyst at the Union of Concerned Scientists, said, “As of a percentage of where all their electricity will come from, Minnesota is now in the lead with this policy in terms of supporting new renewable energy development.”

Minnesota’s previous objective was to encourage power producers to draw 10 percent of retail electricity from renewable sources by 2015.

“As states are catching up with us, we want to raise the bar,” Pawlenty said.

Under the new law, more than a dozen utilities and municipal power consortiums would be bound by the 25-by-2025 standard. Xcel Energy Inc., which delivers half of Minnesota’s electricity, would have to meet a 30 percent by 2020 benchmark.

Xcel is now producing 7 percent of its Minnesota power from renewable sources, said Dave Sparby, acting president and chief executive of the company’s Minnesota operations. Xcel was already under orders to go that route as part of a nuclear waste storage deal from the mid-1990s.

Xcel expects to have 4,000 megawatts of wind online by 2020, the equivalent of 2,000 additional turbines.

Noble said that with Xcel’s 30 percent and other utilities ramping up, Minnesota should be able to reach an aggregate 25 percent of renewable power by 2020.

There are escape valves, including an energy credit trading system to help producers struggling to meet the standard. Utility regulators could also delay or modify the timeline if they determine that the cost of meeting it would significantly increase customer bills.

Sparby said customers should “see no difference at their end of the switch, including the price they see on their bill.”

Beth Soholt of Wind on the Wires advocacy group said it’s too soon to say how much work will be needed to move the power around. But she said Minneota’s growing power appetite would have meant new transmission lines regardless of the source.

“We would be constructing this transmission for reliability and for other types of generation if we weren’t doing it for the wind power,” she said.

Minnesota’s move comes as states around the country stake out far-off goals for renewable energy.

More than 20 states have some type of renewable requirement or good-faith objective. Colorado legislators are moving toward a standard of 20 percent by 2020, while New Hampshire Gov. John Lynch challenged lawmakers last week to adopt a 25 percent by 2025 requirement.

Clean-energy advocates are also pressuring Congress to adopt a goal of getting 25 percent of the nation’s energy — electricity, motor fuel and other power — from renewable sources by 2025 and reduce reliance on foreign imports.