By Joe Trueblood, Superintendent of the Sheboygan Water Utility
With an abundance of flat roofs and good southern exposure, the Sheboygan Water Utility has been contemplating adding solar photo-voltaic panels for some time. Why would a municipal water utility want to also produce electricity?
In recent years, the cost of solar panels has dropped. Large energy producers, such as Alliant and Madison Gas & Electric, have invested millions of dollars in new, large-scale solar installations. This trend will displace production of electricity by burning coal in the very near future.
The Water Utility uses a lot of electricity to move water through the treatment process and then through the more than 205 miles of water mains serving the City of Sheboygan. After investing in ultra-premium efficiency motors, upsizing critical water mains to minimize losses, and wisely using its storage tanks, the next step was toward more sustainable energy, such as solar.
Partnering with Arch Electric of Plymouth to review options, the Board of Water Commissioners settled on a modest initial plan to produce a capacity of 20 kW by installing solar panels on the administrative office roof. At a price tag of just below $60,000, this plan had a payback period of close to 13 years and a lifetime of at least 20 years with minimal maintenance costs.
Arch Electric also won the bidding to supply and install the system. So in April 2020, installers descended onto the office building roof and began installing the panels onto the ballasted membrane rooftop. Proper orientation and anchoring are essential to ensure maximum energy production and durability. Tie-in to the existing electrical meter supply from Alliant is also critical. In rare times when the electricity is not used in the admin building, it goes into Alliant’s distribution system, offsetting usage on the electrical meter.
With more solar power on the way in Sheboygan County, the Water Utility had a modest goal with its 20 kW system. At peak capacity, 20 kW is enough electrical power to supply 200 one-hundred watt light bulbs. This is typically about 30% of the power consumed by the administrative office building.
System start-up took place in May with no difficulties. Final approval from Alliant came in June. Now the system is fully operational, generating electricity whenever the sun is shining. Even when there is some cloud cover, the system will produce electricity, although reduced from the 20 kW full rating. Remote monitoring software shows current production, historical data, savings in CO2, and other important data.
So now, in addition to producing drinking water, the Sheboygan Water Utility is producing electricity. Passersby on Park Avenue can just see the tops of the panels, aimed southward and always ready for action.