Generation |
 |
Mandate
To optimally operate and maintain Eskom’s electricity generating assets for the duration of their
economic life.
The Generation division operates 27 power stations with a total nominal capacity of 41 995MW,
comprising 35 726MW of coal-fired stations, 1 860MW of nuclear, 2 409MW of gas-fired and
2 000MW hydro- and pumped-storage stations, as well as the 3MW wind farm at Klipheuwel.
Operating highlights
• |
Safety performance has shown an improvement, with 28 lost-time injuries (LTIs) and a lost-time
incidence rate (LTIR) of 0.21 for the year to March 2014, compared to 0.37 for the same period
in 2012/13 |
• |
The contractors’ safety performance also reflects an improvement, with LTIR improving from
0.41 in 2012/13 to 0.26 in 2013/14 |
• |
Eskom’s particulate-emissions performance for 2013/14 was 0.35 kg/MWhSO which was
marginally better than the target of
0.36 kg/MWhSO (2012/13: 0.35 kg/MWhSO) |
• |
Water usage for the financial year showed improvement at 1.35 L/kWhSO compared to the
previous year (2012/13: 1.42 L/kWhSO) and against a target of 1.39 L/kWhSO |
• |
Environmental non-conformances identified in the pre-compliance notice issued to Lethabo
power station were successfully resolved |
• |
Koeberg Unit 2 ended its record run of 484 days when it was shut down for refuelling outage
number 20 on 24 March 2014, improving on the Koeberg Unit 1 record of 454 days set in
September 2001. This is Koeberg’s first continuous run from one scheduled refuelling outage
to another |
• |
On 23 October 2013, Koeberg Units 1 and 2 achieved a new record of 184 days with both units
operating simultaneously. The units also sustained zero unplanned automatic grid separations
(UAGS) trips during the year |
Operating challenges
• |
Regrettably, two contractor fatalities occurred at Lethabo and Duvha power stations |
• |
Rotational load shedding was implemented for 14 hours on 6 March 2014 |
• |
On 30 March 2014, Eskom experienced an over-pressurisation incident in the boiler of Unit 3 at
Duvha power station, taking the 575MW unit out of service for a prolonged period |
• |
Continued system pressures and poor-quality coal limit opportunities for planned plant
maintenance and reduction of load losses |
• |
The challenge of sustainably improving Generation’s technical performance in the long term,
while minimising the impact on the security of supply |
• |
A decision on the request for a variation of Kriel power station’s atmospheric emission licence
was received on 28 February 2014. The decision does not allow for continuous operation of the
station at full-rated power on a sustainable basis |
• |
The enforcement actions initiated by the Department of Environmental Affairs against
Camden and Matimba power stations in 2012 for alleged non-compliance with environmental
requirements, and to which Eskom responded in the same year, remain unresolved. Feedback
from the authorities on the matter is outstanding |
• |
Coal-related energy losses were experienced, mainly at Tutuka and Arnot power stations, due
to poor coal quality and supply issues |
• |
With the outage plan and the outage backlog being spread over five years, the turnaround
in UCLF performance will not be seen immediately. In terms of the Generation sustainability
plan, it is estimated that 18 months will be required to achieve stabilisation, whereafter an
improvement in UCLF is expected to be observed |
• |
While there is commitment to adhere to the maintenance outage plan, the unpredictable
performance of power stations and tight reserve margins still require that some outages are
deferred. The result is a further delay in the turnaround of power station performa |
Future focus areas
• |
There is a need to achieve a predictable and sustainable performance within the Generation
sustainability strategy of the “80:10:10 target performance base” over five years to 2017/18
(80% EAF, 10% PCLF and 10% combined UCLF and OCLF, with 9% UCLF and 1% OCLF).
The 2013/14 financial year is the first full year on this strategy |
• |
In 2014/15, a 10% PCLF level will be targeted. Of this target, 8% will be used for scheduled
maintenance with limited flexibility and 2% will be utilised for short-term emergency maintenance
including weekend maintenance |
• |
Managing the risks regarding the extension of ashing facilities on additional land adjacent to
power stations, and the implications of mining and prospecting rights limiting Eskom’s access
to such land |
• |
Eskom aims to achieve compliance to environmental requirements, specifically: atmospheric
emission licences, waste management permits, water use licences, environmental
authorisations and biodiversity related permits and will continue to implement the compliance
programme1 |
• |
Eskom is seeking to obtain a five-year postponement for some power stations of the minimum
emission standards in terms of section 6 of the Listed Activities and Associated Minimum
Emission Standards1 |
• |
To achieve the minimum level of particulate emission discharge, Eskom will retrofit the fabric
filter plant to at least five power stations up to and including 20171 |
• |
Continue implementing the programme to achieve Blue drop (water treatment) and Green drop
(sewerage works) certification by
March 2016 |
• |
Preparation and resource allocation is in progress to ensure adherence to the requirements
of the promulgated construction regulations regarding monthly safety inspections for all
contractors on site |
1. |
For risks relating to atmospheric emission licences, please refer to the “Reducing Eskom’s environmental footprint and pursuing low-carbon growth” section (page 127) in the integrated report. |
Benchmarking
Coal-fired stations
Generation benchmarks the performance of its coal-fired power stations against those of the
members of VGB (Vereinigung der Großkesselbesitzer e.V), a European-based technical
association for electricity and heat generation industries. VGB’s objective is to provide support to
and facilitate the improvement of operating safety, environmental compatibility and the availability
and efficiency of power plants used for power and heat generation, either in operation or under
construction.
When interpreting the results of the benchmark, it should be noted that the operating regimes
of the other utilities contributing to the VGB database may not be the same as those of Eskom.
The graphs that follow illustrate the results of the benchmarking for the 2000 to 2012 calendar
years (the VGB results for 2013 are not yet available). The VGB data for 2012 reflects information
gathered from 123 VGB member generating units, but does not include data from Eskom’s units.
The Eskom data on the graphs has been plotted to the end of the 2013 calendar year to show
the trend. The trend in Eskom’s performance continues to be worse than the VGB benchmark.
The availability indicator of the top performing stations in the VGB benchmark has historically
been consistent, with a slight decline in 2012. The availability of the stations in the median and
worst quartiles has been declining. The benchmarking information indicates that Eskom units are
on a par with the VGB benchmark with respect to planned maintenance in the median and low
quartiles. The PCLF of Eskom’s best performing units was significantly better than that of VGB
benchmark units. However, the UCLF trend is not at the same level. In the 2012 calendar year
Eskom’s units’ performance was worse than the VGB benchmark on all quartiles, with the trend
for 2013 indicating that Eskom units will perform even worse than the benchmark. With the very
tight demand versus supply situation and the need to keep the lights on, Eskom has focused on
risk-based and statutory maintenance rather than the reliability and design-based maintenance
needed to improve the UCLF performance.
With respect to the use of available plant (energy utilisation factor (EUF)), all Eskom coal-fired
units are performing at a level close to, and in many cases above the VGB best quartile. This
indicates that Eskom is operating its power station units at much higher load factors than the VGB
benchmark units, negatively impacting on plant performance.
Eskom’s use of available plant (EUF) is on the VGB best quartile, although the mix in the loading
has changed with the European utilities no longer operating on coal base load. The trend is
indicating that Eskom’s units have consistently maintained a high EUF. This said, Eskom units are
trending significantly higher than VGB compared to the previous years, due to the need to load
available plant more to meet demand.
Benchmarking EAF % all coal sizes 2000-2012 |
 |
Benchmarking UCLF % all coal sizes 2000-2012 |
 |
Benchmarking PCLF % all coal sizes 2000-2012 |
 |
Benchmarking EUF % all coal sizes 2000-2012 |
 |
Koeberg nuclear power station
Eskom is affiliated to the World Association of Nuclear Operators (WANO) and the Institute of
Nuclear Power Operations (INPO), and South Africa is a member of the International Atomic
Energy Agency (IAEA). These affiliations enable Eskom to benchmark performance, conduct
periodic safety reviews, define standards, disseminate best practice and train personnel.
The last IAEA safety review was conducted during August 2011 with a follow-up review in
April 2013. The last WANO peer review was conducted in November 2011, with a follow-up midcycle
review conducted in April 2013, in preparation for the next WANO peer review scheduled
for July 2014.
Through the INPO, Eskom has obtained accreditation from the National Nuclear Training Academy
in the United States for its systematic approach to training of licensed and non-licensed nuclear
operators at Koeberg. Eskom is the only utility outside the United States of America to receive
such accreditation.
The WANO performance indicators provide a quantitative indication of plant performance in the
areas of nuclear plant safety and reliability and personnel safety. There are currently 14 WANO
performance indicators in use worldwide, as well as a performance indicator index that uses 10 of
these 14 performance indicators.
A selection of WANO performance indicator graphs are shown below. Benchmark data is for 10
calendar years, with a Koeberg mean (the average of two units) to 31 March 2014.
Benchmark trends have remained fairly consistent, with the exception of collective radiation
exposure, which has shown a gradual improvement for all quartiles over the period shown:
• |
The Koeberg 12-month unit capability factor, previously in the third or worst quartiles, is on an
improving trend around the median value |
• |
The Koeberg 12-month unplanned capability loss factor has fluctuated between third and worst
quartiles, but is currently on an improving trend |
• |
The Koeberg 12-month unplanned automatic scrams per 7 000 hours has been in the third
quartile, but has improved to zero at
31 March 2014. Note that for the period shown, both
median and best quartile values are zero |
• |
The Koeberg 12-month collective radiation exposure has mostly been in the third quartile, but
has now improved to the second quartile |
• |
The Koeberg 36-month collective radiation exposure has mostly been in the third quartile, but
has now improved to the second quartile |
• |
The Koeberg 18-month (fuel cycle based composite) performance indicator (INPO) index has
mostly been in the worst quartile, but has now improved to second quartile |
Koeberg 12-month unit capability factor (UCF) vs the median, best and worst quartile for all pressurised
water reactor (PWR) units worldwide
Unit capability factor |
 |
Koeberg 12-month unplanned capability loss factor (UCLF) vs the median, best and worst quartile for
all pressurised water reactor (PWR) units worldwide
Unplanned capability loss factor |
 |
Koeberg 12-month unplanned automatic scrams per 7 000 hours (UA7) vs the median, best and worst
quartile for all pressurised water reactor (PWR) units worldwide
The worldwide best and worldwide mean graph lines are both close to zero on the graph below
Unplanned automatic scrams |
 |
Koeberg 12-month collective radiation exposure (CRE) vs the median, best and worst quartile for all
pressurised water reactor (PWR) units worldwide
Collective radiation exposure |
 |
Koeberg 36-month collective radiation exposure (CRE) vs the median, best and worst quartile for all
pressurised water reactor (PWR) units worldwide
The smoothing over a longer period than used in the benchmarks above takes into account the frequency of refuelling outages, of which three
occur per two-year moving window
Collective radiation exposure |
 |
Koeberg INPO index vs the median, best and worst quartile for the units that are members of WANO
Atlanta Centre. This sample includes various reactor types
INPO index |
 |
 |
Damage to the coal conveyor at Duvha power station |
Performance
Key financial statistics for the year ended 31 March 2014
R million |
Actual
2013/14 |
|
Actual
2012/13 |
|
Actual
2011/12 |
|
Operating maintenance costs1 |
7 763 |
|
5 945 |
|
4 936 |
|
Capital expenditure (excluding capitalised borrowing costs)2 |
10 200 |
|
8 512 |
|
6 590 |
|
Total property, plant and equipment3 |
93 465 |
|
85 169 |
|
73 728 |
|
1. |
This is after the capitalisation of costs which are included in capital expenditure. The gross maintenance for Generation, before capitalisation is R14.3 billion (2012/13: R10.6 billion). |
2. |
Includes capitalised maintenance costs. |
3. |
Balances for property, plant and equipment represent the net book value. |
Operating maintenance costs
The year-on-year maintenance cost has grown incrementally as a result of extensive planned
and unplanned maintenance. The UCLF figure of 12.61% and the PCLF figure of 10.50% are
indicative of the level of maintenance that was executed.
Capital expenditure (excluding capitalised borrowing costs)
There has been extensive capital expenditure on general overhauls. This is in support of the
Generation sustainability strategy.
Total property, plant and equipment
The two factors that have contributed significantly to the growth in property, plant and equipment
is the commissioning of Komati Unit 3 (transferred from Group Capital) and extensive capital
expenditure on general overhauls.
Technical performance for the year ended 31 March 2014
Indicator and unit |
Target
2013/14 |
|
Actual
2013/14 |
|
Actual
2012/13 |
|
Actual
2011/12 |
|
EAF, %1 |
80.00 |
|
75.13 |
|
77.65 |
|
81.99 |
|
Normal UCLF, %2 |
9.00 |
|
12.61 |
|
12.12 |
|
7.97 |
|
Less: Constrained UCLF, %3 |
– |
|
1.63 |
|
3.41 |
|
– |
|
Underlying UCLF, %4 |
– |
|
10.98 |
|
8.71 |
|
– |
|
Normal PCLF, %5 |
10.00 |
|
10.50 |
|
9.10 |
|
9.07 |
|
Underlying PCLF, %6 |
– |
|
10.77 |
|
– |
|
– |
|
Normal OCLF, %7 |
1.00 |
|
1.75 |
|
1.13 |
|
0.97 |
|
Underlying OCLF, %8 |
– |
|
3.11 |
|
– |
|
– |
|
UAGS/7 000, ratio9 |
4.00 |
|
5.24 |
|
4.09 |
|
3.19 |
|
EUF, %10 |
80.41 |
|
83.55 |
|
81.87 |
|
79.43 |
|
1. |
EAF – measures plant availability, including planned and unplanned unavailability and energy losses not under plant management control. |
2. |
Normal UCLF – measures the lost energy due to unplanned energy losses resulting from equipment failures and other plant conditions. |
3. |
Constrained UCLF – is the 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. |
4. |
Underlying UCLF – is the UCLF that is the difference between normal and constrained UCLF and that is still within Generation control. |
5. |
Normal PCLF – is energy loss during the period because of planned shutdowns. |
6. |
Underlying PCLF – is the sum of the normal PCLF and the constrained PCLF (the apportionment of the constrained UCLF (refer 3. above) that
is assigned to PCLF). |
7. |
Normal OCLF – is energy loss during the period because of unplanned shutdowns due to conditions that are outside Generation management
control. |
8. |
Underlying OCLF – is the sum of the normal OCLF and the constrained OCLF (the apportionment of the constrained UCLF (refer 3. above) that
is assigned to OCLF). |
9. |
UAGS/7 000 – indicates the ratio of unplanned unit trips per 7 000 operating hours. |
10. |
EUF – measures the degree to which energy was produced compared to the extent to which it could have been produced. |
Generation capacity
Despite the constrained system, more planned maintenance was done in 2013/14, including
significantly more maintenance that was scheduled in the winter months. The power plant
availability (EAF) of 75.1% for the year to 31 March 2014 (2012/13: 77.6%), against a target of
80%, reflects the increase in both unplanned unavailability, as well as the increased planned
maintenance. Generation aspires to reach the 80% EAF target over five years as it increases
its efforts and focus in driving sustainability of Generation’s assets. A total of nine maintenance
outages were scheduled and completed – a good achievement to meet winter demand and do
more maintenance than before. Refer to the maintenance backlog on page 32.
As generating units are taken off-load for maintenance during periods of constrained capacity,
this necessitates increased usage of the open-cycle gas turbine (OCGT) stations when Eskom is
unable to meet demand. The total production by the OCGT stations reached
3 621GWh against
a budget of 1 284 GWh in 2013/14 (2012/13: 1 905GWh). The actual load factor on these plants
for the year to March 2014 was 17.16%, against a budgeted factor of 6.08% (2012/13: 9.03%).
The board approved an increase in the original 2013/14 budget for the diesel usage at the OCGT
stations from R3.6 billion to
R11.3 billion for the year, subject to shareholder support. The total
OCGT stations spend for 2013/14 was R10.6 billion (2012/13: R5.0 billion), a significant overexpenditure
on the original budget. This has a significant negative impact on Eskom’s financial
health and ratios.
The following mechanisms, over and above the use of OCGTs, assisted Eskom to meet the daily
peak demand during the year:
• |
The support of customers with interruptible load agreements (i.e. the Bayside, Hillside and
Mozal aluminium smelters) |
• |
Demand-market participation (DMP) and emergency DMP |
• |
Independent power producers |
• |
Demand-side management (DSM) |
• |
Municipality assistance |
• |
More expensive tariffs during peak periods encouraging customers to reduce demand |
Significant events during the year
Coal conveyor fire – disruption of normal coal supply to Duvha power station
On 20 December 2013 a fire broke out at the overland coal conveyor transfer house outside the
Duvha power station security fence, caused by a conveyor rubbing against the structure. Although
the belt had tripped out, a fire had started. This incident negatively impacted coal stock days and
coal cost for the power station.
The recovery of the one conveyor stream was completed at the end of March 2014. There are
still some defects that need to be addressed but coal is being delivered via this conveyor. The
recovery of the second stream is still in progress and is targeted for completion in the first quarter
of the new financial year.
Rotational load shedding on 6 March 2014
Rotational load shedding took place for 14 hours on 6 March 2014 from 08:00 to 22:00. Refer to
the “Leading and partnering to keep the lights on” section (page 103) in the integrated report for
more information.
Duvha Unit 3 over-pressurisation incident
On 30 March 2014, Eskom experienced an over-pressurisation incident in the boiler of Unit 3 at
Duvha power station, taking the 575 MW unit out of service. As the incident happened right at the
end of the year, it has no material impact on the UCLF for the current year. However, as Unit 3 will
be out of service for a prolonged period, it will have a material impact on UCLF going forward, until
such time as the repairs have been completed. One person was treated for dust inhalation but no
other injuries were reported. The incident is still under investigation.
Plant performance
EAF
The generating plant availability has decreased during the year to March 2014, compared to the
same period in the previous year, as a result of an increase in unplanned unavailability as well as
the increased planned maintenance. The overall availability (EAF) is below target.
UCLF
The unplanned capability loss factor (UCLF) for the year to March 2014 is slightly higher than
previous years, indicative of ageing plant and related deteriorating plant health conditions as
well as the impact of the increased 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.
Breakdown of system UCLF (%)1
|
Actual
2013/14 |
|
Actual
2012/13 |
|
Normal UCLF |
12.61 |
|
12.12 |
|
Less: Constrained UCLF |
1.63 |
|
3.41 |
|
Underlying UCLF |
10.98 |
|
8.71 |
|
Less: Total major/significant incidents |
1.58 |
|
2.69 |
|
Underlying UCLF excluding major/significant events |
9.40 |
|
6.02 |
|
Less: Outage slips |
1.15 |
|
0.84 |
|
Underlying UCLF excluding major/significant events and outage slips |
8.25 |
|
5.18 |
|
1. The breakdown of UCLF as shown above has only been tracked from 2012/13, thus comparatives prior to this are not available. |
The main contributors to UCLF were:
Partial load losses
The partial load losses continue to contribute significantly to the system total unplanned losses,
and continue to increase. The unplanned capability loss factor attributable to these losses was
5.24%, contributing 42% of the system UCLF.
The main power stations that contributed to these energy losses to date were:
• |
Duvha |
24% |
• |
Kriel |
15% |
• |
Majuba |
13% |
• |
Arnot |
12% |
The main reasons for the partial load losses were problems at the draught plant (23%), mills
(16%), turbine (14%), gas cleaning (10%) and feed water (10%).
Boiler tube failures
Boiler tube failures are typically the result of welding repair damage, corrosion, fly ash erosion, etc.
In the year to March 2014, there were 210 boiler tube failures, with a UCLF of 2.18%, contributing
17% to the system UCLF. This is higher in both number and UCLF contribution when compared
to the previous year, when a total number of 191 failures and a UCLF contribution of 1.95% were
recorded.
The main power stations that contributed in the current year were, in order of energy loss:
• |
Kriel |
19% |
• |
Duvha |
13% |
• |
Matla |
13% |
• |
Lethabo |
11% |
• |
Majuba |
10% |
Major/significant load losses
The unplanned capability loss factor against major/significant events was 1.58%. The table that
follows lists the events that occurred:
Unit |
|
Cause |
|
UCLF% |
|
Drakensberg Unit 4 |
|
Stator earth fault |
|
0.270% |
|
Hendrina Unit 3 |
|
Fabric filter plant fire |
|
0.229% |
|
Hendrina Unit 2 |
|
Turbine blade failure |
|
0.206% |
|
Majuba Unit 1 |
|
Turbine shaft bearing failure |
|
0.166% |
|
Kriel |
|
Incline conveyor fire |
|
0.140% |
|
Hendrina Unit 1 |
|
Low-pressure turbine blade failure |
|
0.123% |
|
Matla Unit 1 |
|
Boiler tube failures after the general overhaul |
|
0.082% |
|
Duvha |
|
Overland conveyor fire |
|
0.069% |
|
Lethabo Unit 5 |
|
Generator transformer failure |
|
0.068% |
|
Kriel Unit 5 |
|
Condenser tube leaks |
|
0.045% |
|
Tutuka Unit 1 |
|
Boiler tube failure |
|
0.031% |
|
Multiple unit trips |
|
|
|
0.012% |
|
Duvha Unit 3 |
|
Over-pressurisation incident |
|
0.004% |
|
Other |
|
|
|
0.136% |
|
Monthly UCLF % over the last three years
UCLF |
2013/14 |
|
2012/13 |
|
2011/12 |
|
April |
16.06 |
|
8.20 |
|
6.92 |
|
May |
10.86 |
|
9.51 |
|
7.15 |
|
June |
9.62 |
|
7.27 |
|
6.02 |
|
July |
9.89 |
|
8.53 |
|
5.73 |
|
August |
11.88 |
|
10.79 |
|
6.85 |
|
September |
11.40 |
|
15.11 |
|
7.69 |
|
October |
12.06 |
|
13.40 |
|
7.51 |
|
November |
13.99 |
|
12.48 |
|
11.16 |
|
December |
14.33 |
|
13.43 |
|
8.18 |
|
January |
11.36 |
|
14.10 |
|
10.99 |
|
February |
12.83 |
|
15.04 |
|
9.27 |
|
March |
16.01 |
|
15.97 |
|
8.07 |
|
EUF
The utilisation of available plant capacity (EUF) was significantly higher than target and higher
than the previous four years due to the increased loading of available plant to meet 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 at 99.52% and peaking stations (including the
OCGT stations) achieved 20.72%.
UAGS/7 000
Unplanned automatic grid separations (UAGS) per 7 000 operating hours is a reliability indicator.
For the year to 31 March 2014, the UAGS/7 000 ratio is 5.24, with 527 UAGS trips (2012/13:
UAGS/7 000 ratio of 4.09 and 409 UAGS trips).
OCLF
The unplanned unavailability percentage due to factors outside of management control (OCLF)
for the year to 31 March 2014 was 3.11% (including constrained UCLF) and 1.75% (excluding
constrained UCLF). This is mainly the result of coal-related load losses experienced mainly at
Tutuka and Arnot power stations, due to coal supply and coal quality challenges.
PCLF
As of March 2014, PCLF (reflecting the energy loss during the year because of planned shutdowns)
was 10.77% (including constrained UCLF) and 10.50% (excluding constrained UCLF) against a
target of 10.00%. On average, more planned maintenance has been done this year than in the
previous six years, resulting in a higher PCLF. Although the PCLF has increased, the bulk of the
planned maintenance that was executed was risk-based unscheduled maintenance rather than
design-based preventative maintenance.
As seen below, during the 2013/14 year the monthly PCLF has increased over the winter months
when traditionally minimal planned maintenance was performed.
Monthly PCLF % over the last three years
PCLF |
2013/14 |
|
2012/13 |
|
2011/12 |
|
April |
7.94 |
|
13.81 |
|
8.66 |
|
May |
10.48 |
|
10.36 |
|
6.44 |
|
June |
9.79 |
|
7.41 |
|
4.59 |
|
July |
7.98 |
|
5.45 |
|
2.90 |
|
August |
6.96 |
|
5.44 |
|
6.01 |
|
September |
9.58 |
|
5.27 |
|
7.99 |
|
October |
11.87 |
|
8.74 |
|
9.48 |
|
November |
12.04 |
|
9.63 |
|
7.70 |
|
December |
13.50 |
|
13.06 |
|
15.62 |
|
January |
14.69 |
|
13.07 |
|
12.57 |
|
February |
13.69 |
|
9.70 |
|
13.10 |
|
March |
9.81 |
|
8.85 |
|
13.51 |
|
Maintenance backlog reduction strategies
Eskom’s coal-fired generating units require routine maintenance to ensure that they meet technical
performance requirements, are safe to operate and do not violate environmental laws.
Refer to the “Leading and partnering to keep the lights on – decreasing the maintenance backlog”
section (page 114) in the integrated report for more information.
The power station enhancement project
The power station enhancement project quick-win actions have almost been completed:
• |
All waves were rolled out by the end of June 2013, as per schedule |
• |
Majuba, Kendal, Matla and Matimba have implemented 100% of their quick-win actions |
• |
Kriel, Hendrina, Tutuka and Lethabo have completed between 80% and 96% of their quick-win
actions |
• |
Implementation of quick wins for wave four commenced as per schedule |
Medium- and long-term actions are outage dependent and are therefore impacted by the
deferment of outages. While this project operated as a standalone project in 2012/13, it has now
been incorporated with the Generation sustainability strategy and implementation is continuing.
Energy-efficiency improvement programme
The energy-efficiency improvement programme aims to improve the heat rate of the units at
Eskom’s 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.
The heat rate gap analysis at each station has been converted into an equivalent MW electricity
for units sent out (MWe USO) into the grid. Measurement and verification studies were conducted
using the services of independent accredited SANS 50010 institutions by comparing MWe USO
to a known baseline of performance.
Average annual station heat rate (MJ/kWh)
Station |
2013/14 |
|
2012/13 |
|
2011/12 |
|
Arnot |
12.09 |
|
12.35 |
|
2.58 |
|
Camden |
13.25 |
|
12.64 |
|
13.38 |
|
Duvha |
11.51 |
|
11.11 |
|
11.10 |
|
Grootvlei1 |
13.35 |
|
12.25 |
|
– |
|
Hendrina |
12.77 |
|
13.35 |
|
12.91 |
|
Kendal |
11.72 |
|
11.30 |
|
10.36 |
|
Komati1 |
– |
|
– |
|
– |
|
Kriel |
12.01 |
|
11.34 |
|
11.73 |
|
Lethabo |
10.32 |
|
10.44 |
|
10.55 |
|
Majuba |
11.46 |
|
10.66 |
|
11.30 |
|
Matimba |
11.14 |
|
11.19 |
|
10.94 |
|
Matla |
10.83 |
|
10.69 |
|
11.15 |
|
Tutuka |
10.97 |
|
11.05 |
|
11.75 |
|
Average coal-fired power station heat rate |
11.49 |
|
11.25 |
|
11.46 |
|
1. Grootvlei and Komati are return-to-service stations and thus have less historic plant performance data compared to other stations. |
While some stations have attained and sustained heat rate performance improvement gains,
the overall heat rate (plant performance) 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 have impacted the execution of technical projects as well as coal
qualities at certain power stations.
Koeberg performance
Unit 1
• |
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 |
• |
Unit 1 was taken off load for refuelling outage number 20 on 11 November 2013 and returned
to service after 49 days, on
29 December 2013. This was slightly later than planned |
 |
Koeberg Unit 2 completed an uninterrupted run from one scheduled refuelling outage to the next |
Unit 2
• |
On 24 March 2014, Koeberg Unit 2 was shut down for refuelling outage number 20, having
been online for 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 scheduled refuelling outage to the next |
• |
The unit operated at a load factor of 97.1% for this period, and sent out 10 490 917MWh to the
grid. The production cycle included a two-month period of coast-down at the end of the cycle.
This results in the unit output slowly reducing from 100% to about 60% prior to shutdown, and
hence the final load factor was below 100% |
On 23 October 2013 Koeberg Units 1 and 2 achieved a new record of 184 days with both units
operating simultaneously.
Koeberg’s units sustained zero UAGS trips during the year.
Safety
Regrettably, two contract employees lost their lives. Of these, one related to a fall from height and
one related to an electrical contact incident.
Notwithstanding the fatalities, the safety performance for Generation has improved compared to
the previous year. Generation experienced 28 lost-time injuries (LTIs) during the 2013/14 financial
year compared to 55 for 2012/13. The 28 LTIs include eight noise-induced hearing losses. The
12-month moving average LTIR was 0.21 (target: 0.36), compared to 0.37 for the same period in
2012/13. The number of days to recuperate from injuries is also showing a decrease.
The 2012/13 LTIR for Generation is now reflected as 0.37 because of the late reporting of a noise-induced
hearing loss incident.
The performance of Generation contractors is also showing an improvement. During the year,
34 LTIs (LTIR 0.26) were reported compared to 54 LTIs (LTIR of 0.41) in the 2012/13 financial
year. The LTIs in 2013/14 include the two fatalities as well as a noise-induced hearing loss incident.
Public exposure to radiation
Public exposure to radiation arising from Koeberg operations remains well within the limits set
by the National Nuclear Regulator. Exposure to radiation is measured in units of milliSievert
(mSv). The limit recommended by the International Atomic Energy Agency for public exposure to
radiation is 1.0 mSv per year. However, the National Nuclear Regulator has set a stricter limit of
0.25 mSv per year for
South Africa.
The following graph indicates that the average public exposure to radiation arising from Koeberg’s
operations has been less than
0.005mSv in recent years – less than 2% of the stricter limit
imposed by the National Nuclear Regulator.
Public individual radiation exposure due to effluents from Koeberg |
 |
Environmental performance
Particulate emissions
Eskom’s particulate emissions performance for 2013/14 was 0.35 kg/MWh sent out, which was
better than the target of 0.36 kg/MWhSO, and the same as the performance for 2012/13.
Power stations with fabric filter plants continue to sustain low emission levels. However, challenges
are experienced with emissions at many of the stations with electrostatic precipitators. This is due
to a range of factors, including capacity constraints and lack of access to plant for maintenance
and repairs, as well as maintenance execution. At some stations, a combination of a decline in
coal quality and the high load factors result in the dust-handling plant being over-burdened.
Compliance with National Emission Standards
Refer to the “Reducing Eskom’s environmental footprint and pursuing low-carbon growth” section
(page 127) in the integrated report for more information regarding Eskom’s retrofit programme
to reduce emissions as well as the impact of the new atmospheric emission licences on Eskom.
Emission offsets
There is support from both the Department of Public Enterprises and the Department of
Environmental Affairs for the implementation of household emission offset projects (for example,
through insulating houses and subsidising liquid petroleum gas to replace the use of coal or wood
for heating and cooking in houses). Though these offsets will not reduce Eskom’s emissions, it
will improve ambient air quality and reduce human exposure to high levels of pollution at a fraction
of the cost of emission abatement retrofits at power stations. Eskom is investigating options, and
is currently initiating a household emission offsets pilot project to test the effectiveness of this approach.
Water performance
Water usage for all commissioned power stations for the year to 31 March 2014 was at 1.35 litres
per kilowatt hour sent out (L/kWhSO), better than the target of 1.39 L/kWhSO (2012/13:
1.42 L/kWhSO).
The improved performance is due to an increase in the proportion of energy generated by dry-cooled
stations, as well as increased opportunities for maintenance, implementation of initiatives
identified by the water management task teams, good rains and the increased recovery of water
compared to previous year.
Water management task teams at the power stations are addressing the reduction of water usage
and legal contraventions, compiling comprehensive action plans to address all aspects of water
management and water-use performance.
Significant progress has been achieved in terms of Eskom’s drive to obtain Blue and Green drop
certification status for its water treatment and sewerage works management at power stations.
Environmental compliance
There were 24 environmental legal contraventions in the year to 31 March 2014 compared to
33 for the year to 31 March 2013. The nature of contraventions this year is summarised below and
is broadly similar to previous years:
• |
10 air emissions contraventions, three of which relate directly to the new atmospheric emission
licences |
• |
Five water-release contraventions |
• |
Five land and biodiversity degradation (ash-line leaks) |
• |
Three sewerage spills |
• |
One oil spill |
One environmental legal contravention was declared against Generation, in terms of the
operational health dashboard, during the financial year. The contravention is associated with the
failure of Hendrina power station to effectively and timeously manage water-related environmental
legal contraventions that took place between October 2012 and October 2013. Generation has
already implemented measures to address the deficiencies identified.
A pre-compliance notice issued to Lethabo power station in 2012 was successfully closed by the
Department of Environmental Affairs. The department indicated that no further enforcement action
will be taken against Lethabo power station.
The enforcement actions initiated by the Department of Environmental Affairs against Camden and
Matimba power stations in 2012 (for alleged non-compliance with environmental requirements)
and to which Eskom responded in 2012, remain unresolved. Feedback from the authorities is still
outstanding. Eskom continues to implement the commitments made to the authorities to resolve
the issues raised in these enforcement actions.
All Generation power stations have successfully maintained their ISO 14001 environmental
management system certification status. There has been an overall increase in environmental
skills within the division with the appointment of additional staff, as well as staff participation in
focused interventions aimed at addressing increasing environmental legislative requirements and
operational challenges.
Environmental performance indicators for Generation
Indicator and unit |
2013/14 |
|
2012/13 |
|
2011/12 |
|
Environmental legal contraventions, number |
24 |
|
33 |
|
34 |
|
Environmental legal contraventions reported in terms of Eskom’s operational health dashboard, number1 |
1 |
|
1 |
|
1 |
|
Relative particulate emissions, kg/MWh sent out |
0.35 |
|
0.35 |
|
0.31 |
|
Specific water use, L/kWh sent out |
1.35 |
|
1.42 |
|
1.34 |
|
Net raw water consumption, ML |
317 052 |
|
334 275 |
|
319 772 |
|
Material containing polychlorinated biphenyls thermally destructed, tons |
– |
|
– |
|
– |
|
Materials containing asbestos disposed of at registered waste sites, tons |
276.1 |
|
– |
|
308.3 |
|
Carbon-dioxide emissions (absolute), Mt |
233.3 |
|
227.9 |
|
231.9 |
|
Carbon-dioxide emissions (relative), kg/kWh2 |
1.01 |
|
0.98 |
|
0.99 |
|
Nitrogen-oxide emissions, kt3 |
954 |
|
965 |
|
977 |
|
Sulphur-dioxide emissions, kt |
1 975 |
|
1 843 |
|
1 849 |
|
Low-level radioactive waste generated (net), m3 |
180.8 |
|
183.1 |
|
184.7 |
|
Low-level radioactive waste disposed of at Vaalputs, m3 |
324.0 |
|
54.0 |
|
53.8 |
|
Intermediate-level radioactive waste generated (net), m3 |
28.7 |
|
34.7 |
|
25.4 |
|
Intermediate-level radioactive waste disposed of at Vaalputs, m3 |
178.0 |
|
– |
|
128.0 |
|
Public individual radiation exposure due to effluents, mSv |
0.0012 |
|
0.0019 |
|
0.0024 |
|
Ash produced, Mt |
34.97 |
|
35.3 |
|
36.2 |
|
Ash sold, Mt |
2.4 |
|
2.4 |
|
2.3 |
|
Ash recycled, % |
7.0 |
|
6.8 |
|
6.4 |
|
Ash disposed of on Eskom ash dumps, Mt |
32.4 |
|
32.9 |
|
33.8 |
|
1. |
Under certain conditions, contraventions of environmental legislation are classified in terms of the Eskom operational health dashboard index.
These include instances where censure was received from authorities, non-reporting to authorities as may be legally required, non-reporting
in Eskom, a repeat legal contravention, or when the contravention was not addressed adequately. Group or divisional executives can escalate
any significant environmental legal contravention to the operational health dashboard. |
2. |
Factor figures are calculated based on total energy generated by Eskom (but excluding electricity used by pumped-storage schemes). |
3. |
NOx reported as NO2 is calculated using station-specific emission factors, which have been measured intermittently between 1982 and 2006, and tonnages of coal. |
|