The impact of the power disruptions last year was profound. It touched
the lives of every South African in some way or another, and had an
impact on confidence in the country and its image abroad.
At the beginning of this financial year the power system was still
vulnerable, largely due to the inadequacy of the reserve margin1.
The problem was exacerbated by low coal reserves at our power
stations, as well as quality-related issues. The heavy rains in January
and February 2008 made the handling of coal a near impossibility
at some stations.
A year later the status of the electricity system has changed dramatically.
A decrease in demand together with the technical recovery of the
Eskom power system brought about a much healthier reserve margin,
moving from around 5% in January 2008 to about 14% this January
Coal stockpile days for the system were taken from an average of
12 days in January 2008 to an average of around 41 days, with every
power station having stockpile levels above 20 days. There are still issues
with the quality of coal, but collaboration with the collieries has improved
dramatically. The stations vulnerable to rain have stockpiles of about five
days of coarse coal treated with chemicals to resist moisture filtering in.
This strategy proved successful at most stations in January 2009 with
limited coal-related load losses at these sites despite very high rainfall.
Since the launch of the technical recovery actions in February 2008,
a significant improvement in technical performance has been achieved.
The generation plant performance was stabilised by winter 2008 and
the required level of plant availability and reliability achieved to meet
customers’ electricity demands.
While the principles and lessons learned through the recovery initiative
are being progressively applied to all other plant areas, the focus now
moves to achieving a sustainable performance level within an environment
of severe financial constraints.
Transmission’s 2008/9 interruption performance shows a significant
improvement compared to the 2007/8 performance. Of the three
major incidents recorded, two were the result of problems with the
gas-insulated switchgear at the Invubu substation, while the third related
to load shedding.
The Distribution availability index is
marginally worse than the previous
year, but the interruption duration
and frequency index has improved.
The impact of planned interruptions
was reduced due to better outage
coordination and increased utilisation of
live line techniques.
However, the constraints on Eskom’s energy supply will continue until
new power stations start coming online in 2012. In the mean time,
the Eskom demand-side management (DSM) initiative aims to reduce
national energy demand by 3 000MW by March 2011 and a further
5 000MW by March 2026. This, among others, involves the installation
of energy efficient technologies to alter the load profile of Eskom. Since
the inception of DSM in 2003 up to end March 2009, a total cumulative
saving of 1 999MW has been achieved.
The Eskom build programme is on track to deliver the projects as planned.
Over the five years to March 2013, Eskom will spend R385 billion
in nominal terms on capacity expansion. South Africa needs to build
40 000MW of new generation capacity by 2025, of which 12 476MW
are already under construction (mainly Medupi and Kusile power
stations, return to service stations and Ingula power station). Since the
programme began in 2005, we have already commissioned 4 454MW.
A further 6 184MW will come on stream within the next five years
(which includes the 2009 calendar year). This includes the completion of
the two remaining old coal-fired stations being returned to service, the
upgrade of Arnot power station and the first three units of Medupi and
the first unit of Kusile.
Some 1 962km of high-voltage transmission lines have been built in
the past four years, as well as numerous new transmission substations and transmission network upgrade projects. The construction of the
765kV ultra high-voltage line to the Cape is progressing well, with
430km already strung. The Apollo substation refurbishment was
completed in May 2008. This increases the availability of the Cahora
Bassa/Apollo high-voltage direct current interconnection.