Johannesburg - The City of Joburg is considering generating power from sources ranging from sewage to water pipes to help end electricity cuts that shutter shops and cause traffic gridlock.
The options, along with solar power and tripling output from a coal-fired plant on the eastern outskirts, are among those being explored as a national electricity shortage threatens to subject the city to cuts for years.
Johannesburg has a metropolitan population of about 8 million.
The situation was a “national issue” and must be approached in new ways, said Sol Masolo, a spokesman for City Power, Johannesburg’s electricity distributor.
“Now we have a clear focus on projects that we do to mitigate load shedding,” or scheduled cuts, he said.
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Persistent power cuts shut businesses, leave residences without lighting and disrupt transport as traffic lights are taken offline.
That has a cost.
Eskom cuts power in four stages, according to the severity of the shortage on a given day.
Stage 1 sheds 1 000 megawatts nationally, stage 2 cuts supply by 2 000MW and stage 3 by as much as 3 000MW.
Stage 4 is the reduction of 4 000MW.
A full month of stage 1 cost businesses nationally about R6 billion a month, said Mike Schussler, the chief economist at economists.co.za.
Eskom has reached stage 3 on three days this year and regularly announces stage 2 cuts.
It increased rolling blackouts on Friday to stage 2.
Johannesburg Mayor Parks Tau this month announced plans to use in-pipe turbines to create energy from the citywide water system, similar to a system used in Portland, Oregon, and to convert sewage to gas by using bio-digesters.
The city zoo has a system that uses anaerobic bacteria to convert “zoo poo” into gas.
City Power has over two years installed about 30 000 “smart meters that warn customers to reduce consumption before potential blackouts and can limit the power they use”.
Already that has allowed the city to reduce the scope of some outages.
City Power also had a control system that allows it to switch off water heaters in certain areas of Johannesburg, Masolo said.
While renewable energy is favoured, some of the most effective solutions seen by cities are more traditional ones.
The coal-fired Kelvin power plant, owned by Nedbank Group and Investec – is currently supplying about 200MW to City Power, or about 7 percent of the metropole’s needs.
“We are engaging with the private sector to secure investment in Kelvin to push its capacity to at least 600 megawatts,” Tau said. – Bloomberg