The Eskom board will, before the end of January, consider a new approach to the maintenance of its ailing coal fleet – one premised on creating more time and space for intensive maintenance and repair, whereby the utility makes a firm commitment to only a minimum level of supply that falls well short of demand.

The resultant supply/demand gap would then have to be met through a combination of new emergency supply and demand-side management. Should such solutions fail to address the imbalance, however, Eskom would then resort to ongoing routine load-shedding.

COO Jan Oberholzer tells Engineering News Online that such a strategy  would probably have to be sustained for a period of about two years so as to arrest the poor state of the existing coal fleet and fix the problems that have emerged at Medupi and Kusile.

Oberholzer likened the proposed strategy to the strict maintenance regime adhered to at the Koeberg nuclear power station, in the Western Cape, which is currently acknowledged to be the best-performing station in the Eskom system.

On January 6, Koeberg Unit 1 was once again synchronised to the grid, following a 100-day outage for refuelling and routine maintenance. “We need to show the same level of respect to the coal units.”

Eskom’s generation division was still finalising details, but Oberholzer repeated the 25 000 MW minimum-supply figure outlined in December. If implemented, such an arrangement would result in a supply deficit of about 5 000 MW but also leave Eskom with space to conduct simultaneous maintenance on units with a combined capacity of about 18 000 MW.

PROPER MAINTENANCE

“I believe Eskom needs to be bold and say truthfully to the public of South Africa that we have 25 000 MW 24/7, 365 days a year and then take whatever buffer we have and maintain our units. If it’s time for a 12-year general overhaul, or a nine-year general overhaul, or a midlife refurbishment, or routine maintenance we take the unit off and we maintain it properly. If it’s a 60-day, a 75-day or a 90-day outage that’s what we do and we replace whatever we need to.”

The board submission was likely to include a range of guaranteed-supply options, however, and Oberholzer stressed that the 25 000 MW figure remained a theoretical one for the time being.

The 5 000 MW figure is in line with the shortfall communicated by President Cyril Ramaphosa during a briefing held at Megawatt Park on December 11, two days after the State-owned utility took the hitherto unprecedented step of declaring Stage 6 load-shedding, representing rotational cuts of 6 000 MW. Stage 6 was implemented after Eskom lost 15 000 MW as a result of unplanned breakdowns.

The Energy Intensive Users Group of Southern Africa subsequently calculated that some 46% of South Africa’s installed base of 47 GW was unavailable on December 9 as a result of planned and unplanned outages, as well as partial load losses.

LOAD-SHEDDING RESUMES

On January 4, unplanned breakdowns surged to nearly 16 000 MW, and after yet another conveyor-belt failure at Medupi, Stage 2 load-shedding was declared on January 5 in an effort to limit diesel burn at the open-cycle gas turbines, as well as to replenish dam levels at the pumped-storage plants ahead of the start of the first full work week of 2020.

The decision to declare load-shedding on a Sunday when demand was only about 23 000 MW was not anticipated by the utility and was undertaken despite Ramaphosa’s assurance that Eskom would keep the lights on until at least January 13.

Oberholzer described the high level of breakdowns in December and early January as a consequence of the “neglect, under maintenance and abuse” of a coal fleet whose average age was 38 years.

He also dismissed suggestions that the recent rise in unplanned or partial load losses could be attributed to a rise in so-called “opportunistic maintenance”. Although he confirmed that Eskom had increased its level of planned maintenance during the period from 3 500 MW to 6 000 MW.

The outlook for the coming weeks and months “remains tough” and the prognosis could deteriorate further should Eskom fail to secure emissions exemptions this week from the Department of Environmental Affairs for two units at Kendal that have been failing to comply with air-quality stipulations.

MIND THE GAP

On December 13, the Department of Mineral Resources and Energy (DMRE) released a request for information (RFI) designed to inform an emergency process for the procurement of between 2 000 MW and 3 000 MW of both demand-side management and power generation capacity “that can be grid-connected in the shortest time at the least possible cost”.

Respondents to the RFI were given until January 31 to make submissions.

The department intended following up the RFI with a so-called ‘Risk Mitigation Power Purchase Programme’, which “would complement other initiatives to give effect to the Integrated Resource Plan 2019 (IRP 2019)”.

No mention was made, however, of the launch of further procurement rounds for renewable energy, or any of the other procurement programmes that were expected to be initiated following the long-awaited promulgation of the IRP 2019 in October.

Projects under the Risk Mitigation Power Purchase Programme must be able to connect at intervals of between three to six months and six to 12 months, from issuance of a notice to proceed.

The DMRE has also not yet announced any change to the policy, legislative and regulatory framework for small-scale distributed generators, as well as larger self-generation plants, which are either unable to proceed under the existing framework, or  are mired in red tape.

Currently, distributed generation plants of above 10 MW require specific Ministerial permission to proceed. Plants below 10 MW are able to proceed in the absence of such permission, but require either registration (sub-1 MW) or licensing with the National Energy Regulator of South Africa.

The South African Photovoltaic Industry Association estimates that up to 2 000 MW of small-scale capacity can be added to the energy mix over the next 12 months should the blockages be cleared.

In an opinion article published by Daily Maverick in December, Ramaphosa said that government was “determined to remove the bureaucratic constraints to self-generation and have those users with the capacity producing their own power”.