Crawley Borough Council has announced £85,000 worth of solar panels will be installed at the K2 leisure centre.
A spokesman said the 400 solar panels would be installed at the site in Pease Pottage Hill, Tilgate, by April and start saving the council £16,000 per year.
Cllr Colin Lloyd, Cabinet member for Environment, said: “This is a great improvement to K2 Crawley, which is already doing its bit to be environmentally-friendly.
“This investment will be beneficial in the long run for both taxpayers and the environment as we will see reduced carbon emissions and substantial savings.”
The scheme is part of a council initiative for the town to carbon neutral by 2050.
Local supplier Ecosphere will begin installing the panels next Tuesday (March 17).
The building had a solar panel system installed in 2013.
The panels will double its energy maximum potential output from solar power.
The spokesman said: “It is expected to generate an additional 79,000 kWh of electricity annually with a consequent reduction in CO2 emissions of 42,000kg each year.
“The existing system has already generated 182,000 kWh of electricity with reduced CO2 emissions of 96,000kg and savings of £36,000.”