Robot greenskeepers may take over

A committee of Ozaukee County supervisors last week voted to recommend spending more than $400,000 to buy 28 robotic lawn mowers that would cut the grass at the county’s two golf courses at night and eliminate about 1,900 hours of labor every season.

“It’s definitely been a trend in the industry to switch over,” county Planning and Parks Director Andrew Struck told the Natural Resources Committee.

Struck said the county has experimented with robotic mowers for three years. “We’re very confident in the equipment and the software,” Struck said of the robots.

The courses have relied on four diesel, 100-inch Toro 5010-H fairway mowers as its workhorses.

They are in their 12th year of service, however, and replacing them would cost more than $440,000, Struck said.

“Benefits of robotic mower use include reduced operating labor costs, reduced capital costs, reduced energy costs, reduced maintenance labor costs and healthier turf,” Struck said in a memo to the committee.

Currently, the staff at Mee-kwon and Hawthorne Hills golf courses arrive as early as 3 a.m. to begin mowing the fairways on Monday, Wednesday and Friday, he said.

Fairway mowing accounts for 68 hours per week over an average of 28 weeks, Struck said. The cost of replacement parts for diesel machines vs. robots is similar when factoring in battery replacement costs.

The robots would mow the fairways at night, doing half of each fairway one night and the other half the next night, from 8 p.m. to 8 a.m., he said.

The four conventional mowers will be kept as back-up. Four current back-up mowers will be auctioned.

In daytime, the robotic mowers can be used to mow roughs, further reducing the need to use diesel mowers.

The total mappable acreage of the robotic mowers is 224 acres. The plan is to mow 50 acres of fairways every other day and 75 acres of rough.

Greens will still have to be mowed by hand, but Struck said he expects the technology and equipment to continue improving enough to eventually do those too.

The total price for the four mowers is $385,938, plus a 5% contingency of $19,297, for a total cost of $405,235.

The money to pay for the mowers is coming from the Planning and Parks Department’s golf course capital reserves.

Struck said he thought this would be a first for Ozaukee County golf courses, although the Milwaukee County golf course system has been using robotic mowers for some time.

The purchase must be approved by the County Board.

This story has been edited to reflect the correct number of lawnmowers the county intends to purchase.