Gordhan said Eskom implemented load-shedding for 50 days from January 1 to June 2.
“Five days were at stage 1, 35 days were at stage 2, four days were at stage 3 and six days were at stage 4,” he said.
Herron said Eskom’s dependence on burning diesel was laid bare at Friday’s briefing by its executives, with its ability to procure enough diesel stock evidently regarded among its key performance indicators.
He said the production of renewable energy in SA must be accelerated.
Meanwhile, Cape Town is relying on its Steenbras hydroelectric plant to feed additional power into the grid to “shield” businesses and residents from the full impact of stage 6 power cuts.
On Friday, the 180-megawatt pumped storage scheme reduced load-shedding from stage 6 to stage 4.
“We consider load-shedding above stage 4 to be an acute socioeconomic emergency that requires far-reaching, harm-preventing interventions,” mayor Geordin Hill-Lewis said last week.
“At levels of load-shedding above stage 4, critical infrastructure — including electricity, water, sanitation, and communications assets — is put at even more serious risk than usual. These facilities and equipment are simply not designed to be switched off and on with such regularity, nor do they contain batteries that are able to provide power for upwards of 10 hours per day. Long periods of downtime also leave this infrastructure more vulnerable to theft and vandalism, putting severe strain on our law enforcement resources.”
Load-shedding ramped up to stage 6 is also affecting water and sanitation infrastructure such as sewage pump stations and wastewater treatment plants, which all require electricity to function.
Cape Town’s water and sanitation directorate has taken various measures to navigate the challenges and keep the system functioning during rotational power cuts.
Permanent generators have been fitted at wastewater treatment plants — 85 larger priority water and sewer pump stations were fitted with permanent generators “as a measure to increase the resilience of water and sanitation supply systems”, the city said this week.
Smaller sewer pump stations at risk of overflowing when the power goes have been fitted with early warning telemetric alarm systems, alerting maintenance staff who can intervene to prevent or reduce overflows by using mobile generators to power the pumps.
“However, with severe load-shedding [large areas without power], it is not logistically possible to prevent overflows entirely, in which case the operational teams do their utmost to contain and clean up such flows.
“Most of the city’s water supply is gravity-fed from higher-lying dams. Water treatment plants and critical pumping stations are equipped with standby generators to ensure clean drinking water can continue being provided during load-shedding.
“Some higher-lying areas may experience low pressure or supply disruptions in the event of a power outage affecting the local pump station,” the city warned.
Water is purified at 12 treatment plants across the city which each has an on-site laboratory to test drinking water every two hours, daily. Water flows through a 10,800km network of pumps, reservoirs and pipelines to get to taps in the city.
Various infrastructure and control system upgrades were in the pipeline, the city added.
“In addition, should recreational water bodies or beaches be detrimentally impacted by such sewage spills, the city takes steps to close the water body and alert users about possible health risks by erecting signage and other appropriate communication. Residents are however urged to remain proactively cautious and take steps to avoid entering potentially contaminated water bodies until the extended load-shedding period is over.”
“Load-shedding affects residents and businesses alike. As a city, we need to ensure that our water and sanitation services continue to operate as optimally as possible and the impact on the environment is prevented or reduced to a minimum as far as possible,” said Zahid Badroodien, mayoral committee member for water and sanitation.