Eskom has announced today that it will embark on a massive “maintenance festival” this weekend in an effort to improve the performance and reliability of its power generating units ahead of the expected peak winter demand.
According to the power utility about 64% of their current installed base-load power stations are past their midlife, requiring longer outages and extended restoration time than planned. Midlife refurbishments or replacements are being carried out timeously to reduce equipment failures from occurring, thus improving the ability to provide reliable supply to customers.
Increase of plant performance
Since December last year, the availability of Eskom’s plant performance has improved from 65% to 70%. This is in line with the company’s vision of achieving an 80% plant availability, 10% planned maintenance and 10% unplanned maintenance in the next three years.
The adherence to philosophy maintenance (regular scheduled maintenance) is set to limit unplanned maintenance below 7,500MW in summer and below 5,500MW in winter.
Eskom’s Interim Chief Executive Brian Molefe said: “We have a maintenance backlog due to commitments made to ‘keep the lights on’ and this has led to deteriorating power station availability and subsequent load shedding. We however need a minimum of 3,000MW and a maximum of a 5,000MW buffer either through supply or demand-side options in order to close the backlog within 3 to 5 years and avoid load-shedding. Residential customers can make the biggest difference as demand increases mainly in the evenings.”
Winter power demand
While there is expected to be sufficient power supply to meet demand for the most part of the day, in winter the load increase could be up to 36,000MW particularly over the short sharp evening peak between 17:30 and 18:30.
The increase is predominantly due to the use of electric heaters, geysers and cooking that takes place during this time.
This year winter is expected to be very similar to that of last year. However, the risk is always significantly higher during extreme cold fronts, especially when these occur during the week, as has been the case since winter of 2013. Some generation maintenance will continue to be done throughout the winter, but will ramp down in June to assist in ensuring a sustainable generation fleet.
While the number of the independent power producers (IPPs) that are connected to the grid continues to grow and contribute to meeting the country’s energy demands, the contribution over peak is currently not substantial.
Meeting future power requirements
In an effort to ensure that Eskom will be able to meet future electricity requirements, the company is currently undertaking a ZAR280 billion capital expenditure programme over five
years, and building two of the biggest coal-fired power plants in Africa. Since 2001 Eskom added 32 generating units increasing the number of current units to 121.
In the next 5 years Eskom will add over 17,000MW of new capacity to the national grid, 9,756km of new transmission lines and 42,470MVA of transmission strengthening. To date over 6,238MW of new capacity has already been added and 5,814km of transmission lines and 29,655MVA have been installed.
In addition, Medupi Unit 6 was successfully synchronised to the national power grid for the first time on Monday, 2 March 2015, and is currently being progressively tested and optimised to enable it to join the Eskom Generation fleet as a significant contributor to the country’s constrained power supply.
Medupi consists of six units of approximately 800MW each, for a grand total of 4,800MW, which is 12% of Eskom’s total installed capacity. Eskom is pulling out all stops to ensure that the completion of the remaining five units is not hampered by technical or labour issues.
In addition, Sere Wind Farm near Vredendal in the Western Cape has achieved its full commercial operational capacity of a 100MW on 31 March 2015. The achievement of this milestone is in line with the commitments made by Eskom in terms of both time and cost and the result of successful interaction between Eskom and their contractors.