By Wayne Orthwein

Jensen Center Board member

Amherst is probably the center of renewable energy in Central Wisconsin. It is the birthplace of the Midwest Renewable Energy Association and home to two solar installation companies: Photovoltaic Systems and Northwind Energy. Many local businesses have installed solar photovoltaic (PV) systems including the International Bank of Amherst, the Amherst Telephone Company, Central Waters Brewing, and the Blenker Companies. In addition, there are numerous residential installations.

Given that background, and looking to both encourage the use of renewable energy and reduce the Jensen Center’s energy bills, the Jensen Center Board of Directors decided in 2015 to install a 72-panel, 22.68 kilowatt (kW) photovoltaic array. Local installer Northwind Energy coordinated the installation with a dual project increasing the array size for both the Blenker Companies and Central Waters Brewing. Now, seven years after going online, we decided to review the economics of the project vs. the expectations.

The cost to the Center after all credits was about $53,000, and the life expectancy of the array is 25 to 30 years. Since installation, the array has produced more than 187 megawatt hours (MWh) of power, worth more than $21,000 in retail electric cost, and has greatly reduced the Center’s electric bill. The array has recouped 40% of its total cost and is on track to pay itself off in energy savings by 2030, after which it will continue to produce at no cost for up to another 15 years.

In investment terms, based on what the array has produced over the past seven years, the life-of-array dollar return would be near 5% annually. This is about twice what a 30-year Treasury bond would have yielded at the time. The system is essentially maintenance free and, in addition to the economic benefits, has provided talking points and education opportunities for the science classes next door. If electric rates rise over the next 23 years, the savings will be even greater.