Willmar Municipal Utilities (WMU) in central Minnesota is building a power supply that parallels the state’s renewable portfolio standard of 25 percent renewables by 2025, even though the standard only applies to power generators.
Willmar Municipal Utilities installed two wind turbines in 2009 to increase the amount of clean power in its electricity supply. (Picture by Willmar Municipal Utilities)
The small (9,600 meters), independent distribution utility is acquiring renewables because consumers are concerned about the environment, said WMU General Manager John Harren. “It is becoming the expectation of our customers,” he stated in an interview with a local newspaper.
The renewable share of Willmar Municipal’s power supply is currently at 22 percent. The town’s own wind turbines generate 2 percent, WAPA hydropower represents 13 percent and a mix of contracts with multiple generators makes up the balance. Because the Minnesota RPS only allows hydropower from facilities under 100 megawatts (MW), the WAPA allocation would not count toward the 25-percent goal if WMU was subject to the law.
Started with wind
Willmar Municipal took its first steps toward expanding its renewable supply beyond hydropower in 2009 by building two wind turbines, each with a 2-MW capacity. The estimated payback on the $10-million project is 10 to 15 years.
Initially, the turbine manufacturer DeWind Company of Texas was responsible for service and repairs. However, Willmar Municipal took over operation in August of 2014, training seven of its own employees to climb the turbines and perform maintenance. Local control resulted in more timely service and increased generation in 2015.
Power Supply Manager Chris Carlson said, “We’re making a good faith objective to build up our renewable portfolio.”
The rest of the utility’s power comes from the traditional sources of gas, coal and nuclear. “Even if we had a full fleet of renewables, there will always be a need for some sort of fuel supply for backup sources,” Carlson observed, “for times when there’s no wind or sunshine.”
Proceeding with caution
Pursuing clean energy for its consumers, rather than mandates, gives Willmar Municipal the time to carefully consider the advantages and drawbacks of each opportunity. Contracts with power suppliers have been instrumental in adding renewables, primarily wind and renewable energy certificates. As WMU procures additional purchased power agreements, emphasis will be placed on renewables.
Solar generation is growing more slowly in the Upper Great Plains than in sunnier parts of WAPA’s territory, due to the region’s low utility rates and less robust resource. So far, there is only one customer-owned solar array on Willmar Municipal’s system. However, WMU will consider including a solar garden on a new municipal facility it hopes to build, Carlson noted. “Adding solar will increase our costs, so we want to make sure we have a handle on our power supply before we move forward,” she explained.
Carlson expects the percentage of renewables to continue to grow, even as the city’s load remains stable. “If gas prices go through the roof 10 years from now due to the retirement of fossil fuel plants, we could still hedge our costs with renewables that have zero fuel costs,” she pointed out. “That’s one of the reasons why we aim for a diversified portfolio,” Carlson added.