Business Report 10 Sept

Maintenance raises ghost of blackouts
By SAMANTHA ENSLIN-PAYNE

Durban - Eskom has begun a new round of planned maintenance on its power stations, raising the spectre of the massive power cuts seen in January, which are estimated to have cost the economy R50 billion.

Brian Dames, the head of generation at Eskom, said earlier this week that planned outages had started, with 3 000 megawatts being taken offline.

One 190MW unit is currently out on unplanned maintenance. Load losses - which mean a unit is generating power but not at full capacity - stand at 400MW.

"We are not out of the woods yet with plant condition," said Dames.

Planned outages means the generating units that are operating work harder, sometimes resulting in unplanned breakdowns. "We have to do planned maintenance, otherwise we put the plants at risk."

Eskom did not load shed in winter, but this is no guarantee of a trouble-free summer. Last summer the country was tipped into crisis by a combination of generating units being offline for planned maintenance, unexpected breakdowns of other units, a drastic drop in coal supplies, and wet coal.

Eskom's strategy for this summer's planned maintenance, which will run until early May, is based on lessons learnt earlier this year. But prevention of load shedding is not only in the utility's hands.

A reduction in demand through energy saving in households and businesses would give the utility more breathing space.

The reserve margin between demand and available supply is at an all-time low of about 8 percent, compared with an international benchmark of 15 percent and a recommendation from the National Energy Regulator of SA (Nersa) of 19 percent.

Asked what lessons had been learnt during the January crisis, Dames, who took over the management of power stations and coal supply after the crisis, said the utility was assessing in detail the exact condition of each plant so that problems could be anticipated.

Engineering resources had been consolidated so staff could be used across the fleet of power stations, which would enable them to share knowledge. Planned maintenance was now co-ordinated at senior level.

Lack of co-ordination is one of several criticisms levelled against Eskom by Nersa in a report on the January crisis, published in May.

Thembani Bukula, the head of electricity regulation at Nersa, said yesterday: "We are satisfied with the changes Eskom has made as to how they are going about maintenance."

Bukula said the possibility of a recurrence of the January crisis due to the same factors was very low. But current risks were the lack of energy savings and the failure of multiple generating units, which "we will have to live with for years to come until we have new capacity", he said.

Dames said there was an action plan for recurring and widespread problems such as boiler tube leaks.

Nersa previously took Eskom to task over its poor planning in securing coal supplies, which fell to dangerously low levels in December and January. Plants have coal supplies of 30 days, above a 20-day target.

Eskom has stipulated that certain plants, which are at greater risk from wet coal as their supplies are sourced from open-cast mines, should hold a further five-day supply.

To build in a margin for unplanned outages and load losses, Eskom is studying maintenance schedules for the past 10 years to determine the norm for unplanned outages and load losses. This means there should be capacity to deal with emergencies.

Published on the web by Business Report on September 10, 2008.