The brewery has generated 5,200 kilowatts (kw) since its installation of 111 roof panels and weeks of summer sunshine.
Titanic predicted it would save about 13 tonnes of carbon every year and produce enough energy to brew more than 3m pints of real ale and craft beer a year.
Carbon Trust-certified specialists the Low Carbon Energy Company installed the panels, which it estimated should produce 24,000kw of electricity per year.
Keith Bott, joint managing director of Titanic Brewery described the investment as part of a wider commitment to use green energy and reduce its carbon footprint.
He said: “In line with many other responsible businesses, we are determined to operate in an environmentally friendly manner. The investment in solar will make our beer production energy neutral as we expect to be a net producer of electricity.
“We have looked closely at our energy usage both at the brewery and at our pubs and café bars, and have made changes to reduce our energy footprint where possible.”
Fellow managing director Dave Bott said: “It seems like we have done it at the right time because, ever since, it has been sunny without much exception.”
Bott continued: “There have been some days so far this summer where we have generated more than we have used, so on that point we're getting tariffs for feeding it back into the grid.
"There is cost to it but once that cost has been paid off, the benefits are really quite reasonable."
The brewery previously paid out 13.5p per kilowatt but is now set to save around £5,000 a year.
Dave added: “It's ideal. We're in a fairly typical industrial unit with very shallow roof sections, nearly flat, which is common across the whole country.
"They're just perfect for putting solar panels on because they point in the right direction and it is easy to get solar panels onto the roofs.”