The Roswell City Council has approved a solar energy system for the roof of Mimosa Hall, with excess energy or energy credits to be sold if permitted by state law and the proceeds, reinvested in the historic building and its gardens.

The city and Mimosa Energy LLC are entering into a dollar-a-year, 20-year agreement with optional 5-year extension that also calls for installing a new roof, gutter and soffit system.

Mimosa Hall, a Greek Revival mansion at 127 Bulloch Ave., was built in 1841, extensively renovated in the early 20th century, and acquired by the city for nearly $3 million in 2017.

“As a component of the fundraising support between Friends of Mimosa Hall and Gardens and the city of Roswell, the memorandum of understanding clearly defines the roles and responsibilities for each organization through the city’s operation of the property,” according to a staff report to the council.

The solar system will have a projected capacity of about 22.8 kilowatts DC and be installed on the east- and west-facing roofs of the main house.