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INTEGRATED RESULTS PRESENTATION
KING III APPLICATION
 
   



Improving operations

The technical operations of Eskom’s Generation, Distribution and Transmission line divisions are assessed in terms of the following:

Generation

Unplanned capability loss factor (UCLF) measures the lost energy due to unplanned energy losses resulting from equipment failures and other plant conditions
Planned capability loss factor (PCLF) measures energy loss during the period because of planned shutdowns
Energy availability factor (EAF) measures plant availability including planned and unplanned unavailability and energy losses not under plant management control

Transmission

Total system minutes lost for events <1 minute measures the cumulative number of minutes the system was compromised to the point that electricity could not be relayed, due to transmission system failures or constraints. This metric only considers events lasting less than a system minute. One system minute is equivalent to the loss of the entire system for one minute at the annual peak
The number of major incidents refers to events with a duration of longer than one system minute

Distribution

System average interruption frequency index (SAIFI) is a reliability of supply index and measures how often on average (frequency) the customer connected would experience a sustained interruption per annum (number of times per annum)
System average interruption duration index (SAIDI) is an availability of supply index and measures the average duration (hours) of a sustained interruption the customer would experience per annum (number of hours per annum)

Key indicators of Eskom’s technical operations performance

Indicator and unit
Target
2017/18
 
Target
2013/14
  Actual
2013/14
 
Actual
2012/13
 
Actual
2011/12
 
Target
achieved?
 
Normal UCLF, % 10.00   10.00   12.61   12.12   7.97   Cross  
   Less: Constrained UCLF, %1     1.63   3.41      
   Underlying UCLF, %2     10.98   8.71      
PCLF, % 10.00   10.00   10.50   9.10   9.07   Tick  
EAF, % 80.00   80.00   75.13   77.65   81.99   Cross  
Total system minutes lost for events <1 minute, minutes 3.80   3.40   3.05   3.52   4.73   Tick  
Major incidents, number 1   2   0   3   1   Tick  
SAIFI, events per year 17   20   20.2   22.2   23.7   Equals  
SAIDI, hours per year 39   45   37.0   41.9   45.8   Tick  

1. Constrained UCLF – This is UCLF that was a result of emissions and short-term related UCLF due to system constraints to meet the “Keeping the lights on” objective. This is apportioned between PCLF and OCLF.
2. Underlying UCLF – This is the UCLF that is the difference between normal and constrained UCLF and that is still within Generation control.

A Koeberg worker wears protective clothing that is required for the nuclear sections of the power plant
A Koeberg worker wears protective clothing that is required for the nuclear sections of the power plant

Generation

Eskom aims to optimally operate and maintain its electricity generating assets for the duration of their economic life. Eskom’s operating strategy for generation constantly considers the following factors in balancing national demand and supply:

Electricity demand fluctuates. Eskom aims to ensure that there is enough supply to meet demand. An undersupply of electricity would have negative economic consequences for the country and the company
Plant health is deteriorating, resulting in reduced plant availability and reliability. Eskom needs to do more plant maintenance, but the constrained system does not allow for sufficient planned outages to do so and also affects plans to reduce Eskom’s environmental footprint
System reserve requirements. Over and above meeting the expected demand for electricity, Eskom needs to have generation capacity in reserve to cater for an unforeseen increase in demand, or unplanned plant breakdowns where additional plant capacity will need to kick in to replace the generation capacity lost
Poor-quality coal results in inefficient energy production, places strain on generating plant and negatively affects Eskom’s environmental footprint. Although measures are in place to ensure that suppliers provide Eskom with coal of suitable quality and sufficient quantity, some stations continue to receive poor-quality coal
Potential delays in commissioning new capacity means that the power system remains too constrained to do planned maintenance to existing plant, resulting in plant health deteriorating even further

As a result of previous years’ deferment of maintenance that was required to keep the lights on and the fact that nearly two-thirds of Eskom’s power stations are beyond the mid-point in their expected lifespan, the technical performance of the power stations has been declining over the past few years. The Generation sustainability strategy has been implemented which aspires to Eskom’s power station fleet having on average an energy availability factor of 80%, with 10% set aside for planned maintenance outages and 10% for unplanned outages.

The power station enhancement project quick win actions have almost been completed. Mediumand long-term actions are outage dependent and are thus impacted by the deferment of outages. While this project operated as a standalone project in 2012/13, it is now incorporated within the Generation sustainability strategy.

More planned maintenance is now scheduled in the winter months. The power plant availability (EAF) of 75.1% for the year to 31 March 2014 (2012/13: 77.7%), against a target of 80%, reflects the increase in both unplanned unavailability, as well as the increased planned maintenance. Eskom aspires to reach the 80% EAF target over a period of five years as it increases its efforts and focus in driving sustainability of generation assets. Although the system was tight, Eskom still managed to schedule and complete nine maintenance outages – a good achievement to meet winter demand and do more maintenance than before. Refer to page 114, which deals with maintenance in further detail.

Plant performance

The utilisation of available plant capacity (EUF) was significantly higher than the target and higher than the previous four years due to the increased loading of available plant to match the demand. The overall fleet EUF was at 83.55% (2012/13: 81.87%). The utilisation of the coal-fired units for the year to 31 March 2014 was 92.73%, nuclear achieved 99.52% and peaking (including the OCGT stations) achieved 20.72%.

Eskom did not meet its EAF target, mostly due to an increase in unplanned plant unavailability and energy losses due to incorrect quality coal being delivered, mainly at Tutuka and Arnot power stations.

The unplanned capability loss factor (UCLF) for the year to March 2014 is slightly higher than previous years, indicative of ageing generating plant, the related deteriorating plant health and the high utilisation of the plant. The UCLF for 2013/14 was 12.61% compared to 12.12% in 2012/13 and 7.97% in 2011/12. The impact on UCLF was 1.63% due to decisions by management regarding emission control and short-term outages not undertaken in order to ensure security of supply.

The partial load losses continue to contribute significantly to the system total unplanned losses, and continue to increase. The UCLF due to these losses was 5.24%, contributing 42% to the system UCLF. The main reasons for the load losses were problems at the draught plant, coal mills, turbines, gas cleaning and feed-water systems.

Boiler tube failures are typically the result of welding repair damage, corrosion, fly ash erosion, etc. In the year, 210 UCLF boiler tube failures were recorded, with a UCLF of 2.18%, contributing 17% to the system UCLF. This is higher in both number and UCLF contribution compared to the previous year when a total of 191 failures and UCLF contribution of 1.95% were recorded.

The energy efficiency improvement programme aims to improve the heat rate of the units at Eskom’s 13 coal-fired stations. Heat rate measures the conversion rate of heat from the energy source (coal) to electricity generated. Improvements would indicate an improvement in plant performance and will help reduce Eskom’s environmental footprint, including its carbon emissions.

Average Eskom coal power station heat rate

  2013/14  
2012/13
 
2011/12
 
Average coal power station heat rate, MJ/kWh 11.49   11.25   11.46  

The heat rate improvements in 2012/13 have not been sustained, with a 2.1% deterioration in 2013/14 compared to 2012/13. This deterioration is attributed to the deferment of outages that has impacted the execution of technical plan projects, as well as coal qualities at certain power stations.

Koeberg performance

Koeberg Unit 1 was returned to service on 22 April 2013, following the shutdown that occurred on 20 February 2013 to repair an electrical switchboard fault.

On 24 March 2014, Koeberg Unit 2 was shut down for scheduled outage number 20, having been online for a record 484 days since
25 November 2012, when it was returned to operation after the previous outage. This is the first time in Koeberg’s history that one of the units completed an uninterrupted run from one refuelling outage to the next.

Benchmarking

For benchmarking information relating to Eskom’s coal-fired stations, energy availability and the nuclear power station please refer to www.eskom.co.za/IR2014/10.html

Koeberg Unit 2 completed an uninterrupted run from one scheduled refuelling outage to the next
Koeberg Unit 2 completed an uninterrupted run from one scheduled refuelling outage to the next

Transmission

Transmission provides an integrative function for the operation and risk management of the interconnected power system. This includes balancing supply and demand in real time, trading energy internationally, buying energy from independent power producers (IPPs), and operating the transmission grid.

Good transmission technical performance was achieved with zero major incidents, system minutes <1 performance at 3.05 compared to a target of 3.40, and a line fault performance of 1.73 compared to a target of 2.45 faults/100km. Performance vulnerabilities remain due to the ageing assets and unfirm networks. Firmness relates to the degree of redundancy (N–1) as defined in the grid code.

Benchmarking

Transmission took part in a benchmarking exercise with 27 other international transmission companies in 2012/13. The study focused on maintenance and plant performance and identified best international practices for the transmission industry. These studies have been used to identify opportunities for the development of continual improvement objectives and strategies. The results of the 2012/13 study indicate that Eskom’s Transmission substation and line asset performance is marginally below average whilst a significant improvement has been achieved with line asset performance over the previous two years.

Criminal incidents

A sustained reduction in security incidents has meant that no major losses were incurred during the year to 31 March 2014. Nonetheless, theft remains a risk for Eskom as experienced earlier in the financial year, when the theft of copper at a substation resulted in a minor interruption to a rural supply point.

Distribution

Eskom’s distribution network relays electricity from the transmission network to customers, including municipalities that manage their own distribution networks.

There was a significant improvement in the SAIDI performance, achieving an average of 37.0 hours in 2013/14 compared to 41.9 in 2012/13. There was also an improvement in the SAIFI performance, achieving an average of 20.2 events in 2013/14 compared to
22.2 events in 2012/13.

These improvements are due to:

The establishment of additional customer network centres to increase the operational footprint and enable a quicker response to network interruptions
Reduced network downtime by maximising live-line work for planned maintenance
The implementation of a revised network reliability planning standard to improve the reliability of the network, in line with the regulatory requirements of the Distribution grid code
Increased network visibility, to enable remote monitoring and switching of network equipment to reduce the outage time
Improving reliability centered maintenance to reduce the risk of equipment failure
Focused management attention that ensures disciplined execution of all initiatives

Benchmarking

Distribution is currently preparing for a new benchmarking cycle, comparing technical and operational performance with international utilities.

For previous year’s benchmarking information relating to Eskom’s distribution network please refer to www.eskom.co.za/IR2014/11.html

Direct electricity sales for 2013/14 by customer type
Direct electricity sales for 2013/14 by customer type
 
Direct electricity sales for 2012/13 by customer type
Direct electricity sales for 2012/13 by customer type