True love and alumni loyalty have paid tall dividends for Carleton College.

Thanks to a generous couple, the private college in Northfield plans to erect its second big windmill this summer. The lofty pair will spin enough power for more than half of Carleton's needs.

The second turbine is a gift from 1976 graduates Richard and Laurie Kracum of Chicago. She is an active environmental advocate, so when her husband asked what she wanted for their 30th wedding anniversary, she had an unusual request.

"I said, 'How about we build a wind farm?' We laughed," Laurie Kracum said. "It was partly in jest, and partly serious about doing something environmental."

It was a tall order for her husband, accustomed to the usual gifts of jewelry or nice trips. He was thinking "something a little smaller, that's for sure," Rich Kracum said.

"Sometimes you can't get them everything they want," added Kracum, a Chicago equity investment firm director and Carleton trustee. Kracum recalled that his alma mater had one windmill and figured two might make a grove, if not a farm.

Laurie was happy to settle for a 400-foot-tall anniversary gift that her husband donated on her behalf to Carleton. "I thought it was a great idea," she said by telephone from Chicago.

Turns out their $4 million gift was more than needed, and the extra money was used to install solar panels atop two new dorms at Carleton. "[The panels] are working today," Kracum said on a sunny day last week when he was attending a trustees board meeting in Northfield. "You'd have to be a bird to see them."

The wheels of academia turn a bit slower than do turbine blades on a mellow day. The couple's 30th anniversary came and went on July 1, 2008. Three years later, what is likely to be the world's tallest anniversary gift (Guinness World Records doesn't track that category) is expected to go up this summer.

Carleton has received a bid from a windmill maker and expects more this month. The college will choose a 1.6 to 2 megawatt turbine that is estimated to cost from $1.7 to $2.5 million, said Martha Larson, campus energy and sustainability manager.

Once the size and fabricator are selected, bids will be taken for site preparation and erection of the turbine, which will stand up to 410 feet tall with a blade length of about 140 feet.

The windmill will be about a quarter-mile east of the campus on a leased farm parcel, just outside city limits. It is about a mile west of the college's first, 1.65-megawatt turbine, operating since 2004.

Unlike several other windmill projects proposed near Northfield, Carleton says it didn't hear any negative comments in public hearings from the handful of neighbors living near the windmill site. Larson said Dorothea Holden, who has a turkey farm about 2,000 feet from the site, recently expressed concerns.

Holden said Friday that Carleton sent her a letter that didn't respond to her request that it check out claims that inaudible, infrasonic sound waves could harm people living within a half-mile of a big windmill, as her family and farm workers do.

"My concern is whether that sound that I can't hear is going to make people sick," she said.

Larson said there are no scientifically based minimum site setbacks from homes, but Carleton's windmill exceeds both city and county setback requirements. The city has the stricter requirement, 1,000 feet. The nearest home is 1,100 feet from the site, and about three homes are within half a mile, she said.

The turbine received unanimous approval from Rice County commissioners in late December. Northfield officials sent a supportive letter, which noted: "The city council supports local energy generation projects which further our goals of sustainability for the city and region."

An underground transmission line will carry the wind-generated electricity a mile from the new spinner and feed directly into the campus power grid.

Larson said power from the first windmill is sold to Xcel Energy and is equivalent to about 30 percent of campus needs. The second windmill is expected to provide at least another 30 percent of Carleton's power needs, she said.

The Kracums' gift will be a big part of Carleton's climate-action plan, a draft of which trustees reviewed last week, Larson said. The goal is to have no net greenhouse gas and other emissions from the campus by 2050, Larson said. Carleton is one of more than 670 American colleges and universities whose presidents have signed the Climate Commitment Agreement to reach that goal, she said.

Kracum, who grew up in the Twin Cities, noted the turbine also will be dedicated to his older brother David, a college alumnus, who died in September 2008.

The windmill "will have a nice impact on their carbon footprint going forward," Kracum said.

His wife, a board member of American Rivers and other environmental groups, said the turbine will be a gift that keeps on giving, as long as the wind blows.

Jim Adams • 952-707-9996