Energy thought leader at Eskom Mike Rossouw
Photo by: Duane Daws
The key performance indicators (KPIs) for Eskom power station managers are being reworked to ensure a recovery in plant energy availability factor (EAF), which has fallen from over 85% in 2010 to below 75%.
Energy thought leader at Eskom Mike Rossouw said on Wednesday that a recovery in the EAF across the coal-fired fleet remained the cheapest way to securing the supply-side relief required to keep the lights on and cater for economic growth.
In fact, he told delegates to a Fossil Fuel Foundation event that, if the 85% EAF that prevailed in 2010 had been sustained, South Africa would not currently be vulnerable to load-shedding, notwithstanding the delays to the construction of the Medupi, Kusile and Ingula power stations.
The EAF had fallen as breakdowns increased, owing largely to a lack of adherence to prescribed preventive maintenance practices.
In addition, unplanned outages were 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 – was regularly falling below the 2 000 MW regarded as adequate by the system operator.
Below that level Eskom increasingly needed to draw on the expensive open cycle gas turbines, other peaking plants and its demand-response contracts with large users to ensure a grid-system frequency of 50 Hz was maintained. The high levels of unplanned losses, together with planned maintenance of around 4 500 MW, also meant that load-shedding remained an ever-present risk.
Rossouw said the focus was on improving productivity by turning attention to the cost of each megawatt-hour dispatched from the plant, which was the cost of coal, operation and capital expenditure divided by the plant’s nameplate, less energy not available and energy losses.
“The point of the formula is that every single one of those components are under the control of the power station,” Rossouw explained, adding that the aim was to empower the managers to begin taking control of the costs and “engineer ourselves out of the situation we find ourselves in today”.
He reported that work had been done to reduce the number of KPIs for the power station managers, as well as to align them to the recovery in a sustainable recovery in the EAF.
“There is a meeting coming up in two weeks when the [power station managers] will all be compacted on these KPIs.”
However, Rossouw warned that the recovery in the EAF would take time, with Eskom modelling a recovery to above 80% only in 2018.