Saratoga residents learn about planned battery storage at Wood County Solar Farm
SARATOGA − About a year after a consultant told them a solar farm was safe for residents and the environment, residents gathered at the Town Hall to learn how a battery storage facility at the solar farm will affect their community.
A battery storage facility was always part of the plans for the Wood County Solar Farm in Saratoga, said Rick Zimmerman, Alliant resource development manager. Upcoming changes in regulations forced Alliant to start creation of the battery storage facility a couple of years earlier than anticipated, he said.
The Midcontinent Independent System Operator, or MISO, is a nonprofit organization that sets the rules for power companies in the central part of the country, including Wisconsin, Zimmerman said. MISO requires power companies to have 125% of the energy customers need at any given time. The practice has been to average the customer usage over the course of a year, but MISO is in the process of changing the rules to average it over each season, Zimmerman said.
The change requires Alliant to have more power available during the winter season than they can produce with the solar panels, Zimmerman said. Alliant had to come up with a way to meet the new requirements, once they are put in place.
The demand for electricity doesn't always match the amount of electricity the solar panels put out, Zimmerman said. At times, the power production of the panels is shut down when the need isn't there. Alliant can store excess power in the storage batteries to use as a backup, when it is needed.
"We knew batteries would play a role; we just didn't know when," Zimmerman said. "It came on us sooner than expected."
When Kent Syverson, a geologist who owns Syverson GeoConsulting, gave a report to Saratoga residents in August 2021, he said the solar project was safe for the community. However, he warned residents to watch for any indication the company planned to store batteries on the site. Syverson said batteries contain corrosive chemicals that could pose a risk to the environment.
Alliant plans to have enough battery storage at the Saratoga solar site to power 80,000 homes for four hours, said Amber Zuhlke, Alliant resource development. The area where Alliant will keep the batteries is a half mile from the nearest road and .63 miles to the nearest home, Zuhlke said.
Zuhlke showed pictures of battery storage facilities. They looked similar to a group of semitrailers placed on cement pilons lined up in a lot. The storage units are placed on a cement or gravel base, Zuhlke said.
The batteries used are not the same as the lead-acid batteries most people are familiar with, Zimmerman said. Alliant will use lithium-ion batteries for the site. The lithium-ion batteries are completely different. They have very little fluid in them.
Each battery cell is a sealed unit, Zimmerman said. The cells are placed in racks and the racks are placed in the storage units. There is no room to enter the storage units, which are about the size of a semitrailer. All maintenance is done by opening a door and working from outside the unit, Zimmerman said.
The battery cells are monitored by computers, which will shut down the battery's operation for any indication it is operating outside the set parameters, Zimmerman said. The storage containers have fire suppression systems and monitors that report temperatures to the computers. Each unit has its own heating and air conditioning system to keep the batteries at the proper temperature, Zimmerman said. The units also have vents to release gas, if something goes wrong and pressure builds inside the unit.
Regulations state how far apart each of the storage containers must be for safety reasons. The amount of space at the Saratoga facility will allow the units to be farther apart than regulations require, Zimmerman said.
Residents asked questions about the materials used in the batteries and what potentially could be released into the air or ground, if there is an accident. Zimmerman said he would make the specification sheets available to the community once Alliant has approval to proceed with the project and selects which company they'll purchase the batteries from.
Residents also were concerned with what will happen to the batteries once their lifespan, which is 15-20 years, has ended. Alliant hopes the continued increase in battery usage will also inspire an increase in companies that will recycle them, Zimmerman said.
The chemistry used for storage batteries has advanced significantly over the years, Zimmerman said. The lithium-ion batteries are more stable, easier to control and more temperature resistant than the old lead-acid batteries, he said. That, along with all the safety features Alliant plans for the battery storage facility, will make it as safe and environmentally friendly as possible, he said.
"We're not going to build a site dangerous to our employees or dangerous to the communities we serve," Zimmerman said.
Tony Palese, Alliant spokesman, said the company plans to hold more informational meetings in the future. Alliant wants to keep the community informed, he said.
Savion, the company that created the Wood County Solar Farm, which Alliant purchased, is in the process of developing a second solar project in Saratoga. Alliant has not purchased the second project and is not in negotiations to purchase the project, Palese said.
More:Wisconsin DOT looks at possible roundabout for Pittsville intersection
SUPPORT LOCAL JOURNALISM: Our subscribers make this coverage possible. Click to see the Wisconsin Rapids Tribune's special offers at wisconsinrapidstribune.com/subscribe and download our app on the App Store or Google Play.
This article originally appeared on Wisconsin Rapids Daily Tribune: Saratoga residents learn about planned battery storage at solar farm
