(John Kemp is a Reuters market analyst. The views expressed are
By John Kemp
LONDON, March 6 South African power utility
Eskom declared a stage three power emergency on
Thursday, implementing a programme of rolling blackouts to
reduce demand and stabilise the grid.
The blackouts are the first since 2008 but come after the
country only narrowly averted load-shedding on several occasions
in November and February as the grid comes under increasing
Eskom has asked customers to switch off all non-essential
"The power system is very tight," the company warned
earlier. "This risk has increased significantly due to the heavy
rains over the last few days and an increase in technical
problems experienced at some of Eskom's power stations."
Later the company toughened its warnings. "To avoid possible
power failure in your area, switch off everything besides your
TV and one room light," Eskom told customers via its website.
Further problems are expected on Friday, with more heavy
rain forecast. The company has appealed for maximum
In this instance, the short-term trigger for the emergency
was seven days of torrential rainfall in the east of the
country, which has soaked coal stockpiled at power plants.
But the underlying problem is the increasing maintenance
needs and unplanned outages at Eskom's aging power stations,
which have cut the margin of spare generating capacity to
critically low levels and left it unable to cope with further
Electricity consumption has actually grown much more slowly
than either Eskom or the government forecast four years ago.
In 2012, net power delivered to customers was just 249
terrawatt-hours (TWh) compared with the 270 TWh predicted in the
2010 Integrated Resource Plan, which remains the government's
official plan for the electricity industry.
Several factors have contributed to the reduction in
electricity consumption relative to the forecast trajectory.
Eskom's power buyback programme provided incentives for
miners and other industrial customers to cut their consumption
and may have reduced demand by as much as 4 TWh, according to
South Africa's Department of Energy.
Large price increases over the last five years have also
curbed consumption, and some energy-intensive users such as
smelters appear to be relocating activities to countries with
more competitive power prices.
South Africa's traditionally energy-hungry economy appears
to be becoming less energy-intensive in response to rising power
Following the 2008 blackouts, municipalities, the national
government and Eskom have all been aggressively pushing energy
But the government admits that slower growth in demand may
also be due in part to the fact that supply is simply not
In its 2013 update to the Integrated Resource Plan, the
Energy Department notes "the constraints imposed by the supply
situation and the strong likelihood for suppressed demand, by
industrial consumers as well as domestic consumers".
South Africa's power supply theoretically totals over 48,000
Eskom has more than 42,000 MW of its own generation
capacity. Another 3,000 MW is controlled by independent
generators such as Sasol.
The Energy Department estimates the utility can call on
consumers to reduce demand by up to 2,500 MW when supplies run
The problem is that much of the fleet is unavailable.
Following the blackouts in 2008, Eskom has boosted supplies by
postponing scheduled maintenance. However, the result has been a
"deterioration in the performance of the aging fleet", according
to the Department of Energy.
The 2010 Integrated Resource Plan assumed 86 percent of
Eskom's generating capacity would be available on average, but
it has dropped to less than 80 percent.
In recent months as much as 23 percent of Eskom's generation
capacity has been unavailable, according to calculations by
Bloomberg ("Eskom Starts Power Blackouts in South Africa Because
of Wet Coal" March 6).
As capacity margins have narrowed, Eskom has been racing to
bring as many power plants back online as quickly as possible.
But in the long term, the strategy of postponing maintenance
at the cost of deteriorating availability is unsustainable.
"Eskom has proposed a new generation maintenance strategy
that aims to ensure the required maintenance is carried out on
key identified generators, regardless of the demand-supply
balance," the Energy Department explains in its update.
"The final objective is to arrest the deterioration in
performance and return the average availability factor to 80
percent over the next 10 years."
But that could mean even more rolling blackouts over the
next few years as Eskom tries to stabilise the condition of the
(editing by Jane Baird)