THE City of Tshwane has plans afoot to turn sewage sludge into biogas.
THE City of Tshwane has plans afoot to turn sewage sludge into biogas.

The municipality said it believed opportunities existed to convert the sludge from the Zeekoegat sewerage works in Pretoria East into energy as an alternative power source.

Utility Services MMC Darryl Moss said the groundbreaking initiative was based on a feasibility study already undertaken to explore the proposal of a sewage-to-gas source of energy. The study was funded by the German government and was part of the City’s energy strategy to reduce carbon emissions and its environmental footprint through cleaner energy production.

Moss said: “The operation behind it is that you take the sludge from a sewerage plant and you react it to generate biogas, and then you use the biogas as the energy source to drive and generate power.” He said the City’s modern sewerage plant in Pretoria East contained quality sludge which was fairly good and could be used to generate biogas.

“The feasibility study showed that we would generate 80% of the power required for that plant, and we would reduce our carbon footprint on that plant by 70%,” he said.

The investment into the project was relatively low, estimated at about R30 million, Moss said.

“In terms of energy saving we would recover the cost of that investment within a period of four and a half years. The feasibility study is very positive, we are now going ahead with the actual finalisation of a tender document,” he said. He said the City had applied for funding from the national Green Fund, which was established to support green initiatives.

“We should hear the results of that application this month, and if we get funding we will be ready to go out on tender within this financial year.”

Moss also shed light about other plans in the pipeline to open up the power generation space by allowing more role players to generate their own electricity. He said the City was working on drafting an energy strategy which would set, among other things, targets for the municipality in terms of generating renewable energy.

The strategy was initially based on the 2015 energy strategy but had since changed after the DA-led administration devised its own target.

“It is more than just the mix, but it is also about the different approach to energy.

“It is about how we plan to manage both the supply and the demand of energy, our interaction with the independent power producers and consumers.” The strategy is expected to be presented before the mayoral committee meeting this month.

Part of the strategy included the regulation for small scale power generation, to allow more people to put solar panels on their rooftops and sell excess power back to the City.

“It is a very comprehensive document. It covers a lot of very interesting concepts. It is still in draft form, so I can’t give out detailed information because it may change,” he said.