MASON CITY | The Mason City Public Library's solar energy plant has been a sunny success so far, Library Director Mary Markwalter told City Council members Tuesday night.
Coupled with two other related activities, the library utility bill was reduced by $27,000 in the past fiscal year, from $68,000 to $41,000.
It became operational on July 12, 2016, after three years of planning that resulted in 207 solar panels being installed on three of the flat roofs of the library.
"The plant consistently produces 33 percent of the power used daily by the library," said Markwalter, with the only exceptions being cloudy days or when a panel is malfunctioning.
Moxie Solar of West Liberty installed the system. Sun Powered Solutions LLC of Cedar Rapids paid for the materials and construction of the plant, she said.
Sun Powered Solutions entered into an agreement with the library which states that after 15 years, ownership of the plant transfers to the library. "The plant is expected to be productive for 45 years and is guaranteed for 25 years," said Markwalter.
Monthly utility bills are reduced because the library is only billed for power produced and used; there are no taxes or fees or other expenses, she said.
She said two other initiatives have helped reduce energy costs — installation of LED lighting throughout the building; and installing 23 windows that open, reducing the number of days of use of the HVAC system. Both were paid with capital improvement funds.
Markwalter said all of the changes have made the library staff much more aware of energy saving — "conscientious consumption," she called it.
The first talk of solar power at the library began in 2013, In 2014, the city budgeted $375,000 in its capital improvement budget for it — and bids even came in below budget.
But there was a catch — an 18-year payback on the investment. The City Council decided that was too long to wait and rejected the plan.
Markwalter and the Library Board began a diligent search for a way of making solar energy affordable and feasible.
They found Moxie Solar of North Liberty, a company that specializes in solar energy projects.
The unique aspect of the Moxie plan is that the company, not the city, financed the project through private investors.
The company did the installation and will deal with all maintenance for 15 years, after which the city will purchase the system for $15,000 — the fair market value, according to Markwalter.
The city's expense is the cost per watt used and is comparable to what the library would pay a private utility company.
But by using Moxie, Markwalter said, the city avoids having to pay the $300,000-plus for purchasing the solar panels.