Concerns mount over Eskom’s medium-term system adequacy outlook <www.ee.co.za/article/concerns-mount-over-eskoms-medium-term-system-adequacy-outlook.html>
September 23rd, 2018, Published in Articles: EE Publishers <www.ee.co.za/section/articles-eepublishers>, Articles: Energize <www.ee.co.za/section/articles-energize>, Featured: EE Publishers <www.ee.co.za/section/home-featured>, Featured: Energize <www.ee.co.za/section/energize-featured>
by Chris Yelland, investigative editor, EE Publishers 12
. *Following the recent expos**é by EE Publishers on the deepening coal supply crisis facing Eskom <www.ee.co.za/article/the-coal-crisis-at-eskom-worsens.html>, alarm bells are also sounding regarding the utility’s worsening generation plant performance impacting South Africa’s medium-term (five-year) system adequacy outlook.*
There are deepening concerns about the overall state of Eskom’s aging fleet of coal-fired power plants, and the ability of Eskom to meet demand in the next five years. Already, Eskom is operating its emergency open-cycle gas turbines in the Western Cape almost daily to meet demand and avoid load shedding.
Compared to 2017, the energy availability factor (EAF) has significantly deteriorated from 78,61% in 2017 to 73,74% in the 2018 calendar year to date, and the EAF is likely to drop still lower in the summer months of 2018 ahead.
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*Fig 1: Eskom week-on-week energy availability factor (EAF) for 2016, 2017 and 2018 to date.. Click graph to expand. (Graph: EE Publishers; Data Source: Eskom)*
Unplanned plant breakdowns, as measured by the unplanned capability loss factor (UCLF), are significantly higher than expected, while planned maintenance outages remain high, as measured by the planned capability loss factor (PCLF).
To a large extent this unhealthy situation has been mitigated by flat and declining electricity demand. Weekly demand, calculated from the aggregated hourly metered energy sent out (local generation plus imports), has been hovering around 30 GW for the last 8 weeks. If electricity demand picks up, there are likely to be supply constraints.
The total energy sent out (GWh) in the 2018 calendar year to date, compared to the same period in 2017, is down by 0,37% to 4318 GWh as at week 36, 2018, while the peak winter demand for the 2018 year was 34276 MW – down 3,07% from the peak winter demand in 2017.
<www.ee.co.za/wp-content/uploads/2018/09/Peak-demand.jpg>
*Fig. 2: Week-on-week peak demand for 2017 and 2018 to date.** Click graph to expand. (Source: Eskom)*
Eskom’s plant performance for the next five years to from 2019 to 2023, as measured by the energy availability factor (EAF), is forecast to range between 72% (pessimistic) and 78% (optimistic), with a declining trend in the latter half of the five year period. However the EAF currently sits at the lower end of the forecast band at 73,74%.