N1 City Mall’s three in one waste-to-power technology will be on show at this year’s African Utility Week and POWERGEN Africa events.

The property features an on-site, anaerobic digester that uses organic waste to produce green electricity, hot water and fertiliser.

The technology, which was installed by Dutch green technology provider Waste Transformers in partnership with Growthpoint Properties, will be showcased as a case study during the Future Cities conference track at African Utility Week and POWERGEN Africa in Cape Town in May and will be followed by a discussion on how waste-to-energy plants can be made more competitive.

Reducing organic waste to landfill

Commenting on the project Gavin Jones, Growthpoint Properties’ Regional Retail Asset Manager for the Western Cape says the intention of this waste-to-power installation at N1 City with Waste Transformers is to look towards future regulation, particularly in the Western Cape, that will limit the removal of organic waste from operating buildings to landfill sites.

“Cape Town has announced that they want a 100% reduction of organic waste to landfills by the year 2027. And Growthpoint is trying to reach that target by 2020 while Cape Town is hoping to reach a target of 30% by that time.”

Modulated structure functions like a stomach

The Waste Transformers unit is a modulated structure comprising four large containers that are run by a number of processes and occupies about six or seven parking bays onsite at the N1 City mall.

“Within our shopping centre environment we collect organic waste material from restaurants and from food supermarket operators in separate bins and separate it from the recycled goods. We then process it in the first stage of the machine, which is the macerator which chops up the organic waste matter into a usable size,” Jones explains.

“A grey water mix is added and this mixture is then pumped into the anaerobic digester.  With added enzymes, this digester pretty much functions like a stomach which produces methane gas as well as a by-product of hot water.“

The hot water is used to clean the plant and the waste area. The methane gas is harvested, filtered and housed in the gas component of the installation. This gas is then used to run an electric generator which then places electricity back into the shopping centre.