Cape Town – While bouts of load shedding often create severe disruption to the lives of South Africans, the City of Cape Town can shield its customers from some of the impacts.
At present, South Africans have been enduring Stage 3 power cuts until this (Friday) morning, whereafter stages 3 and 2 will again be implemented continuously from 4pm today until 5am on Monday.
The City, however, said that it will protect its customers from stage 3 of load shedding, Cape Town residents will be on Stage 1 from 6am until 4pm, after which they will move to Stage 2 until 10 pm.
From 10pm, City of Cape Town customers will then join the rest of the country on Stage 3 until 5 am on Friday.
Today (Friday) at 4 pm City, customers will experience Stage 1 until 10pm, after which they will experience Stage 3 until 5am tomorrow (Saturday).
On its social media pages, the City said it would announce further developments subject to changes from Eskom.
City of Cape Town Mayco member for Energy, Beverley van Reenen, said to date Cape Town customers had been protected from more than 1 100 hours of Eskom’s 1 900 plus hours of load-shedding between February 2022 and September 2022.
Van Reenen said: “Where possible, the City has been able to protect its customers from up to two stages of load shedding primarily through the management of the Steenbras Hydro Pump Station.”
The 180-megawatt Steenbras Hydro Pump Station (SHPS) consists of four turbines that are used to generate electricity. During peak electricity demand, it channels water from Upper Steenbras to Lower Steenbras, through the turbine generator, to create electricity.
When electricity usage is low, usually between 11pm and 7am, the turbines pump the water back to the Upper Steenbras Dam to be re-used the next day. In this way, SHPS operates like a battery. The amount of electricity that it can generate in one day is limited by the capacity of the lower reservoir.
“Thus about two-thirds of the water used to generate power during the day is pumped back at night to the upper Steenbras reservoir to create more space for continual utilisation of the power station.
“It’s more like charging the cellphone battery at night for usage during the following day. Cape Town is the only city in South Africa to own and operate a large pumped hydroelectric scheme,” Van Reenen said.
Adding that through its excellent and diligent maintenance of this critical and complex infrastructure, the City of Cape Town could help protect customers from the highest Eskom tariffs, as well as from up to two stages of load shedding.
Van Reenen also said that at higher Eskom load-shedding stages, the City garners energy from the use of gas turbines during the evening peaks between 5pm and 8pm, to bolster the capacity of the Steenbras-generated reserves.
“This is used at the high stages of load shedding where possible. It is very important for the City to safeguard critical infrastructure for service delivery to all, as well as to protect its electricity network,” she said.
“The City manages its infrastructure and power generation and distribution well to ensure reliable supply within its powers. We will keep doing what it is doing well and look to innovations to enhance mitigation and protection and build Cape Town’s resilience.
“We will continue to do all we can to protect customers from load shedding where it can, while at the same time working to end load shedding over time.”
“Eskom’s continuous load shedding does impact on infrastructure and increases the risks associated with vandalism and theft of power infrastructure under the cover of load shedding power outages,” Van Reenen said.
In another move to protect its customers from some of the impacts of load shedding, the City of Cape Town has issued a tender that will see customers rewarded for reducing their power usage at a given time so that City-supplied customers can be protected from the impact of load shedding.
“This new initiative is part of our demand response plan to mitigate load shedding while we work on getting new sources on board to end load shedding over time. Apart from IPP and own-build projects, we are working to create an enabling environment to bring more partners on board.
“If one looks at small-scale embedded generation, for instance, the City has allocated R15 million in this financial year to pay for energy generated by small-scale embedded generators through the feed-in tariff of 75,51 c/kWh (excluding VAT) and the 25c/kWh incentive offered for small-scale embedded generators,” Van Reenen said.
The demand response programme forms part of a suite of interventions being put in place by the City to lessen Capetonians’ reliance on Eskom’s failing generation capacity.
The interventions include the ongoing procurement of power from Independent Power Producers (IPPs), which is currently in the technical bid evaluation phase.
The construction of the City’s solar plant in Atlantis is set to begin next year, with more own-build projects planned across the City. The introduction of cash payments for excess electricity produced by commercial customers with their embedded generation facilities, for example, solar panels on factory roofs.
The wheeling project will allow large generators to sell to private consumers at other locations in the city through the use of the City’s distribution grid and lessen the demand for Eskom-produced (and eventually City-produced) power.
“Importantly, all Capetonians have benefited from the City’s power generation management as it also protects critical City infrastructure used for service provision and protects the City’s electricity network,” Van Reenen said.