- The City of Cape Town’s dual efforts to reduce emissions associated with landfill sites and reduce reliance on Eskom continues to gather pace.
- The landfill gas wellfield and flaring system at Vissershok Landfill will begin operations soon to complement existing systems at Coastal Park and Bellville landfills.
- The City is also making steady progress toward the generation of electricity from landfill gas.
For the next three financial years, a total of R86,4 million has been budgeted for the operation and maintenance of a recently-completed landfill gas flaring system at Vissershok Landfill. Furthermore, a system to convert landfill gas from this site into electricity is being designed for implementation around 2024/25, at an estimated cost of R197 million.
Organic matter that ends up in landfills decomposes in the absence of oxygen and forms landfill gas that is rich in methane. This “Landfill gas” is known to have a global warming potential approximately 25 times greater than carbon dioxide. To reduce emissions from the landfill “wells” are dug into the landfill site to extract the gas. The wells are then connected to the flare compound where it will initially be combusted/flared, and in the future be diverted to a gas engine to generate electricity.
Currently, the City is in the process of appointing a service provider to operate and maintain the recently-constructed gas well-field and flaring system at Vissershok. Furthermore, the gas turbine electricity generation system for this site has entered the design phase, with the first 2MW generation infrastructure scheduled for implementation in 2024/25, increasing thereafter up to between 7-9MW of generation capacity by 2026/27, depending on gas yields. According to Eskom, 1MW is about enough to power 650 average homes in South Africa, meaning that this system could potentially supply power for up to 5 850 average homes.
Like similar systems at Coastal Park and Bellville South Landfill facilities, the project has been designed in such a way that the City can earn ‘carbon credits’. A carbon credit is earned when an entity destroys one ton of greenhouse gas, that would otherwise be released into the atmosphere. The City of Cape Town Council recently resolved that these carbon credits would be auctioned off on the South African market to companies who need or want to offset their carbon emissions. Proceeds from the auction will be ring-fenced to fund Urban Waste Management projects that reduce the health and pollution impacts of waste, and that will generate additional co-benefits such as job creation for communities.
At this stage, it is still too early to determine accurately how much greenhouse gas will be destroyed over the life of the project, or how much money the City will save by off-setting our reliance on Eskom, as it depends on gas yields that could vary over the 15-20 year lifespan of the project, depending on patterns of organic waste disposal in the City. However, current estimates show that between the sale of carbon credits and the expected reduction of bulk electricity purchases from Eskom the project should pay for itself at least.
‘The teams who are working on landfill gas flaring activities and electricity generation at landfill sites should be thoroughly commended for the good work they are doing. Although the expected contribution of waste-to-energy activities is not sufficient to reduce loadshedding on their own, the reduction in emissions is significant and will be achieved effectively at no additional cost to the ratepayer.
‘We are nearing the first production of electricity from landfill gas turbines at Coastal Park landfill in the coming months, and the first issuance of carbon credits for landfill gas flaring at Bellville South landfill is expected this year. More news around this follow in due course,’ said Alderman Grant Twigg, Mayoral Committee Member for Urban Waste Management.
Author: Bryan Groenendaal