Students learn why community solar is heating up in Minnesota at Mankato Winter Workshop
By YES! Coordinator Katelyn Larsen
On February 17, 2016, four teams convened at Mankato West High School to learn about community solar. Community solar is a way for residents and businesses to receive solar energy without having to invest in an entire system on site. It is a great fit for those that want to support clean energy but do not have the funds or space necessary to have a Solar Photovoltaic (PV) system at their location. Jim Haler with South Central Electric Association (SCEA) presented to the group about the recent 134 KW community solar array that was installed in Lake Crystal in December 2015.
South Central Electric Association wanted to install a community solar array to meet the needs of its members. SCEA wanted to locate the solar array near its substations to make it easier to maintain the solar array site, so the SCEA approached POET Biorefining-Lake Crystal to see if there was a possibility of locating the solar array on POET’s property near the Northstar substation owned by SCEA. POET loved the idea because it would further their commitment to renewable energy. The 134 KW community solar array was installed by Zinniel Electric in December 2015, and SCEA will be seeking subscribers this spring.
Tim Zinniel of Zinniel Electric broke the project down a bit further for the students, explaining the mechanisms behind solar energy. He explained that PV panels, which are made from silicon, work because the semi-conductors within the panels are excited by light. Each solar panel produces direct current (DC) rather than alternating current (AC), so they require inverters to transition the electricity from DC to AC in order to comply with the grid. However, because the community solar array in Lake Crystal is owned by a cooperative, power supplied from the solar panels will not be transferred to the grid. Rather, all of the energy produced will be used within the SCEA system by the cooperative’s members. Additionally, all of the panels that are part of the Lake Crystal array were installed with reflectors in place. The reflectors bounce more light back to the solar panels, making them more efficient. In fact, according to Zinniel, solar panels with reflectors can produce just as much energy during a Minnesota winter as solar panels without reflectors in Texas. Zinniel recommended using solar panels in conjunction with reflectors as opposed to using solar panels with trackers, which follow the sun throughout the day.
After eating lunch, workshop participants traveled to the POET Biorefining Ethanol Plant in Lake Crystal and were able to view the community solar array from the road. Jim Lambert, General Manager at the plant, and Rick Wellmann, Commodities Supervisor, greeted the teams and provided background information on POET and the production of ethanol. POET cares about its environmental impact and explained to the teams some of the measures its taking to reduce the impact like recycling all of the water used at the plant. After receiving some background information about the plant, students were taken on a tour of the plant where they saw the entire process in action from trucks unloading corn to the fermenters used to produce the ethanol. The POET plant in Lake Crystal produces 56 million gallons of ethanol per year and sources the majority of its corn from farms located within a 50-60 mile radius of the plant.
By the end of the tour, students’ and coaches’ minds were full of new facts gleaned from the day’s workshop. Teams are looking forward to taking the knowledge back and applying the concepts they learned to excel in their projects.