Cottage Glen: A Solar Pioneer in Door County

by MARILYN HANSOTIA and DUANE KEXEL, Cottage Glen Residents

In 2011, Cottage Glen included 32 owners of fourplex, duplex and single-family condominiums, plus a recreation center with indoor and outdoor pools and a full workout room.  

Happily, we realized at that time that our rec center had a south-facing roof sloped at 31.5 degrees, which made it ideally suited for solar panels. We then retained Appleton Solar to install 14.1 kilowatts of roof-mounted solar panels and have closely monitored their performance on a monthly basis ever since.

The purpose of this article is to share the highlights of our solar experience to date and our expectations of the solar panels’ performance over their remaining life through 2041. We hope this will encourage others to explore the potential of solar power, which has become increasingly critical as climate change and the war in Ukraine enhance the value of renewable electricity.

The total installed cost of our solar system in 2011 – net of two Focus on Energy grants and the federal tax credit – was $17,893. In addition, we established two reserve funds to cover inverter replacement and the removal and reinstallation of the panel to allow rec-center resurfacing.

Through April 2022, our system has produced 181,949 kilowatt hours, which was 13.7% of total rec-center usage. With transmission and distribution losses, WPS must produce about 1.087 kilowatt hours per kilowatt hour delivered to our rec center. Thus, WPS generation has been reduced by nearly 200,000 kilowatt hours to date due because of our solar production.

The installation of our system was completed in two weekend sessions in July 2011, when Cottage Glen owners hosted the crews to avoid peak-season room-and-board rates. The system has performed admirably, with no maintenance costs incurred to date.  

The financial benefits to Cottage Glen have been primarily the WPS bill reductions for the rec center, which have totaled $18,516 to date and have now surpassed our initial investment cost. In addition, we were able to sell some Renewable Energy Credits in 2016 and 2017 for $447, raising total benefits to $18,963. 

From a broader perspective, it is useful to note that federal spending proposals must now include the social cost of carbon (SCC) in their justification. SCC is defined as the total damages from emitting one metric ton of carbon dioxide into the atmosphere. The current SCC is estimated at $56, with sharp increases expected for future years.  

The most useful summary of the economics of the Cottage Glen solar project is the return on investment (ROI) over the 30-year expected life. Based solely on base benefits, the ROI is 8.7%. Adding SCC benefits raises the ROI to 13.4%. Either ROI seems quite attractive for those who may now consider a new investment in solar panels.  

Those seeking additional solar data for their specific location should consult the PVWATTS calculator from the National Renewable Energy Lab to obtain estimated kilowatt-hour production and bill reductions to discuss with potential solar installers.If you have questions or want more information, contact Duane Kexel at [email protected].