Students study for months, endure all-night cramming sessions and down gallons of coffee for these kinds of grades.

After months of monitoring Congress, two activist groups said Minnesota’s U.S. senators are in the top of the 107th congressional class for their voting history on energy issues.

Sens. Paul Wellstone and Mark Dayton, both democrats, received grades of “A” and “B,” respectively, from the Minnesota Public Interest Research Group and the local Sierra Club chapter Monday.

While Wellstone got a perfect score, the groups gave Dayton an 83 percent rating for failing to vote to increase U.S. renewable fuel use by 20 percent by 2020. Dayton voted for a 10 percent increase, which subsequently became part of the Senate’s bill.

The two activist groups huddled for warmth in the mouth of the Washington Avenue Bridge on Monday to denounce the current status of the Senate’s energy bill and applaud Wellstone and Dayton for their energy initiatives.

“Sens. Wellstone and Dayton have worked to make this bill what it should be, and we call upon them to keep up the fight,” said Jon Hunter, MPIRG’s energy program associate and a second-year graduate student. “The bill must be improved or it must be defeated.”

They said the Senate’s bill subsidizes fossil fuels and new nuclear plants construction. The bill requires a vehicle fuel efficiency study but not an increase in miles-per-gallon standards. It also repeals an anti-monopolistic act, which they said could encourage Enron-like trading deals within the energy industry.

Senators are expected to vote on April 9 the exploration of the Arctic National Wildlife Refuge.

MPIRG and Sierra Club officials said they have meetings with the two senators this week and want them to vote against the bill if it is not revised to include better energy conservation amendments.

Wellstone was unaware of the rankings Monday, but his campaign manager said the senator plans to make energy policy a major issue in the race against Republican Senate candidate Norm Coleman.

Marc Kimball, Dayton’s communications director, said Dayton has been a big supporter of renewable energy and recently helped pass an allocation of $20 million to increase public education about renewable energy sources.

“Eighty-three percent is pretty good,” Kimball said. “You have to be realistic about what you can accomplish; and if you shoot too high, you may get nothing.”