Cape Town mall turns waste into power and fertiliser
Property development company, Growthpoint Properties, has embarked on a partnership with Dutch green technology provider, Waste Transformers, for an innovative food waste conversion project at a Cape Town shopping mall.
The two companies have collaborated to install an on-site, anaerobic digester at the N1 City Mall in Goodwood to convert organic waste into green electricity, hot water and fertiliser.
According to Gavin Jones, a Growthpoint Properties’ manager, about a third of the food produced in South Africa goes to waste and 90 percent of this waste lands up in landfills.
“Landfills produce methane gas which is worse for the environment than CO² emissions and the South African government is aiming to reduce at least half of that food wastage,” said Jones.
“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 percent by that time.”
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. 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,” said Jones.
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.
“The last product of the system is a liquid fertiliser and is distributed for landscaping at all of our properties in our portfolio in the area, and to a large number of non-profits and hospitals as well as to Parow Golf Course. We have an end goal in mind to begin a micro-enterprise to sell this fertiliser into the market,” explained Jones.
Nardo Snyman, Growthpoint’s sustainability specialist, said: “Organic Waste is one of the last barriers to truly achieving Net Zero waste at a number of our properties.
“With rising levels of pollution in both our country as well as our oceans, it’s no longer a case of best practice to re-purpose our waste but rather a necessity.
“We are excited about this initiative as it is aligned to our commitment to environmental responsibility and economic empowerment. The containerized, small-scale, on-site approach to transforming waste into energy holds great potential for both the South African and developing markets.”
Lara van Druten, CEO of The Waste Transformers: “This project demonstrates how companies can cooperate in a mutually inclusive way that generates energy for positive economic and social change.
“We are excited at the opportunity to transform an unused resource – waste – into new energy for South Africa. And, we are truly delighted that we will embark on this journey with a company with the stature of Growthpoint.”