The Westhampnett solar project near Chichester is expected to generate enough electricity to power around 2,400 homes a year.
The battery is used to store surplus electricity which can be released to the grid when consumer demand is high.
It follows the launch of the Tangmere solar farm in 2015, which already produces power for 1,500 homes a year.
The council has also installed solar panels on its buildings, including offices, schools and fire stations.
Leader Louise Goldsmith said: “Living in the sunniest county, it makes absolute sense for us to use our natural resources and to generate clean energy that can be fed into the local electricity grid.
“As one of the first solar farms to be built with battery storage and free from government subsidy, we are blazing a trail among local authorities and demonstrating that councils have a role to play as local leaders on energy.”
Islington Council will be showing how it used CHP and heat recapture techologies to make a different to the community at Energy Live Expo on 31st October, with Energy Minister Claire Perry headlining the event.
To book your place (free if you are an end user), you can send an e-mail to [email protected].