LUVERNE -- Minnesota has gained national notoriety in the arena of renewable energy with its ethanol and biodiesel mandates and continued expansion in wind energy.
Now the state -- and particularly the 11-turbine wind farm known as Minwind Energy in Rock County -- will make another stride in the push for renewables.
Minneapolis-based Xcel Energy, which purchases power generated from the 11-megawatt wind farm, will begin testing a wind-to-battery project this summer at Minwind's site near Beaver Creek.
It will be the first use of the technology in the United States for direct wind energy storage, according to Xcel.
"It's very interesting for Minwind to be part of this, but it's also good to see a large energy company like Xcel work on adapting these new technologies for our future energy needs," said Mark Willers, CEO of Minwind Energy.
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In 2006, Minwind was part of a pilot project with the Agricultural Utilization Research Institute and South Dakota State University that involved use of a biodiesel-powered generator to keep the turbines operating on days when the wind wasn't blowing.
The new wind-to-battery project will also involve partners, including the University of Minnesota, the National Renewable Energy Laboratory, the Great Plains Institute and Minwind.
"We will assist in the recovery of data and transport it (to the partnering entities for research)," Willers said.
Beginning this summer, 20 50-kilowatt battery modules -- weighing a total of nearly 80 tons and roughly the size of two semi trailers -- will be delivered to the Minwind site. The batteries will be able to store about 7.2 megawatt hours of electricity, with a charge-discharge capacity of one megawatt, said Xcel. Fully charged, the battery (all 20 battery modules) could power 500 homes for more than seven hours.
The batteries will charge when wind powers the turbines. Energy stored in the battery will then be used to supplement the power flow when the breeze is calm. Willers said the idea is to maintain the power supply through thunderstorms, transmission issues or peak load demand.
"Energy storage is key to expanding the use of renewable energy," said Dick Kelly, Xcel Energy chairman, president and CEO, in a press release issued by Xcel. "This technology has the potential to reduce the impact caused by the variability and limited predictability of wind energy generation. As the nation's leader in distributing wind energy, this will be very important to both us and our customers."
While the main focus of the research will be on energy capture and storage, Willers said analysts will also look at how the batteries work and how many turbines can be connected to the project at one time.
"It's much more energy-efficient technology than what's been used in the past," he said. "It's enjoyable that Xcel chose a community project to work with."
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Willers said Minwind was selected for the wind-to-battery project for a couple of reasons. First and foremost, Xcel needs to get more energy on the system, and second, working with a smaller group such as Minwind is just easier.
"We are a little more adaptable to doing some changes," Willers said. "We like to think we have good working relations with Xcel on different ideas."
The battery is expected to go online in October.
It isn't yet known how long the batteries will be in use at the Minwind site. Willers said he has been told it could range from several months to several years.
"It's just another piece to show southwest Minnesota is very involved in wind technology and new technology that is part of the wind industry," Willers said.
The project has been selected to receive a $1 million grant from Minnesota's Renewable Development Fund, pending Minnesota Public Utilities Commission approval.
