One of the main reasons given for the recent suspension ofEskom CEO Tshediso Matona and three other senior executives related to a “lack of credible information” surrounding the poor performance of the existing coal-fired powerplants.
In response, the Eskom board established an independent inquiry into the status of the business and its challenges, including the “poor performance of generation plant”, as well as delays in bringing the new generation plant on-stream, the high costs of primary energy and cash flow challenges.
But with the underperformance of the coal fleet having been analysed intensely in recent months, it is far from guaranteed that this new inquiry will be able to yield anything startlingly new, both with regards to the problems as well as thepossible solutions.
In fact, in a recent speech following President Jacob Zuma’s State of the Nation address, Public Enterprises Minister Lynne Brown, who has supported the suspensions and the inquiry, succinctly summarised the difficulties, while backing Eskom’s proposed plan for dealing with the problem.
Over the past six years, the generating fleet had been run hard to meet demand ahead of the introduction of new capacity, which had been delayed. “What that means is that the scheduled preventative maintenance has been delayed,” Brown has outlined, adding that wear and tear on the equipment atpower stations has increased to the point where there are an “unacceptably high number of breakdowns”.
This point has never been disputed by the utility nor by Matona, who in November and again in January, made a commitment to dealing with themaintenance backlog, while warning that this increased the risk of rotational load-shedding for up to 24 months.
LIVING ON THE EDGE
South Africa will be “living on the edge”, Matona has indicated, until large-scale new capacity can be introduced, or until the existing fleet returns to an energyavailability factor (EAF) of 80% – the EAF from the coal fleet stands at closer to 70% at present.
Until recently, Brown has concurred, telling lawmakers in mid-February thatEskom is now following its preventative maintenance schedules “to the letter and to the highest standards”. “This means that it is taking generating units out of commission for periods of time, even if it results in load-shedding. In this way, over time, all our power stations will be restored and will, once again, be reliable and predictable.”
In other words, both Eskom and Brown have been actively preparing citizens for what will inevitably be a long hard slog designed to restore the existing fleet to a semblance of operational normality.
Only a few short weeks later, though, a probe has been instituted; presumably to unearth information that has hitherto been hidden from view.
But what, in the area of the performance of the coal feet, is the board-led ‘fact-finding’ mission likely to find and how revealing is it likely to be?
The awkward answer is that very little new is likely to emerge. Unless, of course, the Eskom executives and, until recently the Minister, have been engaging in an elaborate disinformation campaign.
The analysis will show, as is already widely known, that there has been a significant increase in breakdowns since 2010. These unplanned outages are not only high, but volatile, with losses, at times, increasing from lows of around 4 000 MW to closer to 9 000 MW over a short period of time.
As a result the capacity in reserve – the difference between the forecast peak demand and the available capacity – has fallen. This is significant, as the systemoperator requires the capacity in reserve to be over 2 000 MW for it to consider the reserve to be adequate.
When it falls below the 2 000 MW level Eskom begins drawing on the expensive open cycle gas turbines, its peaking plants and its demand-response contracts with large users to ensure that the system remains in balance. A grid-system frequency of 50 Hz needs to be maintained to ensure that integrity of the network.
The high levels of unplanned losses, together with planned maintenance of around 4 500 MW, means that, on most days, there is now a 50% chance that the system operator may need to resort to rotational load-shedding to prevent a catastrophic blackout – a failure that could take weeks to repair.
The current prognosis is that this situation is likely to endure until at least the end of 2016, notwithstanding the creation of an action plan designed to accelerate the recovery.
This plan has three main components.
Firstly, the aim is to increase capacity through the new-build programme, which has faced a number of schedule slippages. However, there is a view that the injection of major new capacity is likely to fall outside of the 18-month window, notwithstanding the recent grid synchronisation of Medupi Unit 6.
The second main lever relates to reducing breakdowns within the coal fleet and restoring the EAF to above 80%. Here, too, progress is likely to be slow, owing to the scale of the backlog.
Some observers believe that up to half of the maintenance currently taking place across the 87 coal-fired units is reactive rather than preventative. To reverse the position will require cash, skills and spares (which are all in short supply), as well as time and space to carry out the maintenance.
In parallel, a concerted effort is required to improve coal quality, with coal being responsible for a major portion of the partial load losses currently being experienced across the fleet.
DEMAND & SUPPLY LEVERS
The third key component relates to reducing demand and introducing non-Eskom supply.
In this area, it is understood that government, Eskom and the war room have been considering ways to introduce both demand response aggregators as well as an emergency generator aggregator. The former will contract with those businesses and households that are incentivised to sell back some consumption to the aggregator in times of system constraint. Eskom procures the reduction from the demand aggregators as a unified bloc. Similarly, the emergency generator aggregator will contract with those businesses willing to switch on their back-up generators in an effort to mitigate the risk of load-shedding.
Various other demand management schemes are being considered, as are a range of short-term non-Eskom supply options, including cogeneration fromindustrial and agro-processing facilities, with the immediate focus being on renewing those short-term cogeneration contracts that are due to expire on March 31.
But for Eskom the critical issue, besides the interrelated imperatives of accelerating the build programme and improving its financial position, is restoring the performance of the coal-fired power stations.
The problem has been diagnosed, the remedies outlined and implementation is now meant to be the priority.
It is difficult to see how the board-led probe will dramatically improve on either the analysis of the problem or the proposed solutions. It is also far from clear how implementation of the recovery plan will be accelerated through the board’s intervention of March 11.(by Miningweekly.com)
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