11 September 2013 – Addressing the media yesterday during its Quarterly State of the System Update in Cape Town, Eskom reported on its significant achievements over winter 2013, attributing its success in keeping the lights on to hard work, disciplined delivery of goals and support from customers who heeded the call to switch off from 5pm to 9pm. In addition, there has been progress with its new build programme.
Public Enterprises Minister Malusi Gigaba said: “We undertook certain initiatives, including with the national broadcaster, to rally South Africans behind this collective effort to save electricity, particularly during the peak period. We did so knowing that efforts of one, whether positive or negative, could and would affect all others. I am happy, once more, to report that South Africans responded to our calls unequivocally, cooperating with our national call and taking action responsibility in their workplaces and households.”
Eskom Chief Executive Brian Dames said: “This winter was different in that long duration generation maintenance was planned to be done and was implemented. It is an exceptional achievement to meet winter demand and do more maintenance than before.”
Almost two-thirds of Eskom’s power stations are past the mid-point of their expected operating lives and they therefore require higher levels of planned maintenance work. Like any engine, generating plants need routine maintenance or upgrades that require them to be fully or partly taken out of service.
Of the nine (9) power station units that Eskom had committed to maintaining over the winter to ensure long-term sustainability of the plant, five (5) have been completed, three (3) are currently being serviced, and maintenance on the remaining one will be completed towards the end of this month.
Dames explained that Eskom recently adopted a five-year plan aimed at ensuring a sustainable generation fleet; “one that will not only generate power more reliably now but will continue to do so over the useful lives of our power stations. The new plan will see us target 10% of our generation capacity on average through the year to do fixed planned, design-based maintenance, to address safety, reliability and emissions issues at our power stations.”
In the short to medium-term, this will introduce risks to balancing supply and demand. In order to manage these risks, the country must continue to focus on additional supply options, energy efficiency and some form of an energy conservation scheme. Much of the planned maintenance will be fixed, providing certainty for planning, while outages will be done to ensure we can comply with environmental legislation.
While there was sufficient capacity to meet the demand during the day in winter, a number of evenings were tight with all available generation in service and contracted demand requested to reduce. The highest peak this winter was 35 421 MW on June 11, which was only slightly lower than 35 894 MW recorded on August 7 last year. This can be attributed to a relatively mild winter compared to last year.
Eskom needs to continue an active maintenance programme this summer and is looking to its customers to rise to the challenge of saving electricity, by “Living Lightly this summer.” Dames thanked customers for a magnificent performance so far: “Since we started our demand side management programme in 2005, over 3 000 MW of energy efficiency savings have been achieved – enough to power a city the size of Johannesburg.
“Our Power Bulletin and Power Alert, televised during the evening peak between 5pm and 9pm, have on average resulted in 348 MW demand reduction in electricity usage during the red flightings” said Dames. “We would like to thank all households that had heeded the call to reduce their usage when called upon, and we urge all South Africans to join us in making energy efficiency part of our lifestyles. Let’s “Live Lightly” this summer and help the country to keep the lights on while at the same time reducing our impact on our planet.
The system outlook remains tight in summer, with different challenges due to the summer load profile. Unlike winter, where the demand increases during the evening peak (5pm to 9pm), the demand profile during summer is much flatter (Table Mountain profile) with an increased demand profile throughout the day, primarily due to air-conditioning and geysers. If there is a constraint, the system is constrained for the entire day.
“Unlike winter where residential customers had the greatest impact, during the summer, it is primarily the commercial sector that can make the biggest difference. The challenge is to ensure that there is sufficient generation capacity throughout the day, as we continue with our maintenance plan and focus on reducing unplanned outages,” said Dames.
“This summer, please remember that less is more. The less electricity you use the more electricity will be available to go around,” said Dames.
There is an intense focus on reducing the level of unplanned outages to below 4 500 MW.
The open-cycle gas turbines (OCGTs) will have to run harder during summer. The system remains vulnerable to the higher forced outages requiring stronger reliance on expensive emergency reserves throughout the day.
Cahora Bassa continues to operate at 1 300 MW with the final 200 MW expected to be restored later this year. Approximately 2 100 MW of interruptible demand, for up to two hours a week, is available from the aluminium smelters to help manage the frequency of the power system during unexpected events.
Dames said there has been continued progress with Eskom’s new build programme, with most of the equipment currently being on site at Medupi. Similar progress has been recorded at Kusile and Ingula; and construction of the Sere wind farm has commenced. Technical issues with Hitachi have been resolved at Medupi and are being implemented and progress with the Alstom control and instrumentation issue continues to be made. “To meet this growing demand, Eskom has undertaken a massive capacity expansion programme since 2005. By the end of this decade, we will have added a total of 17.1 Gigawatts to the grid, boosting our capacity by almost 50%, from a range of new plants including return-to-service stations and open cycle gas turbines, as well as Medupi, Kusile and Ingula,” said Dames.
He added that: “These are large and complex projects that take time to build. We have said all along that the power system would remain tight for the next few years, until we get substantial new capacity online from our large new power stations.”
In the meantime, Eskom calls on all South Africans to pull together over the next few months and use electricity sparingly by “Living Lightly” this summer. By switching off every non-essential appliances during peak hours households can help make a big difference.
Less is more this summer and homeowners and businesses can do so with just four steps: first, switching off geysers and pool pumps; second, switching off non-essential lights; third, efficient use of air-conditioners by keeping the room temperature at 23â°C; and finally, responding to the alerts on TV each evening.