Kendal power station
Photo by: Creamer Media
State-owned electricity utility Eskom, which is struggling to keep the lights on as a result of high levels of unplanned breakdowns across its coal fleet, could be forced to shut down units at the Kendal power station at the end of January unless ongoing noncompliance with the country’s minimum emission standards (MES) is addressed.
In December, the Department of Environment, Forestry and Fisheries (DEFF) confirmed that the Green Scorpions had issued Kendal with a compliance notice. The notice instructed the station to shut down units 1 and 5 by January 9 and submit a maintenance plan for units 2, 3, 4 and 6 in order to ensure that Kendal was in compliance with its atmospheric emission licence.
The utility requested an extension until the end of February, but was granted one until only January 31.
This was confirmed by DEFF, which revealed that Eskom requested a variation of the Compliance Notice on January 2. "The variation decision effectively amended the timeframe for compliance with the instructions to the January 31, 2020," the department told Engineering News & Mining Weekly.
"It is further worth noting that an application for the suspension and an objection of the compliance notice were included in the respective submissions that were made by Eskom which they are entitled to do. The aforementioned applications are currently under consideration."
Should Eskom's response fail to satisfy the authorities, however, Kendal could be ordered to halt production at units 1 and 5 – two of the power station’s six 680-MW apiece units that are consistently in breach of particulate-emission limits.
Kendal has been battling to comply with the particulate-emissions component of the MES, which also sets limits for nitrogen oxides (NOx) and sulphur dioxide (SO2), since early 2018. The plant’s performance has worsened materially, however, following strike action in mid-2018 when dust-handling protocols were breached and equipment damaged, following a decision to sustain production amid severe system constraints.
During the strike period, Kendal’s skeleton staff was unable to remove ash at a rate adequate to avoid damage to the electrostatic precipitators, installed across the units to remove particulate matter from the flue gas using the force of an induced electrostatic charge. As a consequence, the plant’s electrostatic precipitators were damaged, with the damage being particularly severe at units 5 and 6.
On average, the Kendal units have been emitting between 200 milligrams per standard cubic metre of air (mg/Nm3) and 300 mg/Nm3, with Unit 5 having, at points, exceeded 1 000 mg/Nm3. For ‘existing plants’ such as Kendal the particulate matter emissions limit is 100 mg/Nm3, while it is 50 mg/Nm3 for new plants.
Unit 5 was shut for maintenance in September and, despite an improvement in particulate-matter emissions since being returned to service in January, emissions continue to exceed the 100 mg/Nm3 limit. Unit 1 is also not operating within the stipulated limit.
Compounding matters for Kendal and several other Eskom power stations, is a 2010 amendment to the National Environmental Management: Air Quality Act stipulating that coal and liquid-fuel power stations, both old and new, should comply with the 50 mg/Nm3 limit set for new plants by April 1 this year.
Controversially, Eskom has also made a submission to DEFF requesting either the suspension of, alternative limits for and/or postponement of MES compliance for several power stations from April 1.
This postponement submission was made in March last year, but DEFF subsequently requested additional modelling, which Eskom has not yet completed. In fact, the utility is still in the process of contracting a service provider to complete the modelling. The utility expects to finalise the submission by the end of May in the anticipation that DEFF will not move to enforce until the updated postponement application is submitted and adjudicated.
Eskom environmental manager Deidre Herbst tells Engineering News & Mining Weekly that the Kendal matter is distinct from the postponement application and is being given priority attention.
She acknowledges, however, that it is unlikely that all Kendal units will be fully compliant with particulate-emission limits by January 31 and that there is, therefore, a risk that the Green Scorpions might order Kendal to cease operating noncompliant units. Should it do so, the risk of load-shedding could increase further.
The utility began resorting to load-shedding again in December, owing to a steep increase in unplanned breakdowns. On December 9, the State-owned utility took the hitherto unprecedented step of declaring Stage 6 load-shedding, representing rotational cuts of 6 000 MW, after Eskom lost 15 000 MW to unplanned breakdowns.
Herbst defended Eskom’s broader application for postponing full compliance with the ‘new plant’ MES for particulate emissions as well as those for NOx and SO2.
Eskom estimates the cost of full compliance to be R300-billion and does not consider the new-plant MES to be “practically feasible or beneficial for South Africa”. It notes that six power stations, with a combined capacity 10 000 MW, will be decommissioned before 2030, while two more, representing 7 000 MW, will be decommissioned by 2035. Only Majuba, Medupi and Kusile are expected to be operational beyond 2044.
Instead, Eskom is proposing a “phased and prioritised approach” to achieving MES compliance at a nominal cost of R67-billion – an expenditure item not yet fully catered for in the tariff.
Under the utility’s proposal, the reduction of particulate matter emissions will be prioritised, along with reduced NOx emissions at the three highest-emitting stations, namely Tutuka, Matla, Majuba.
It is also proposing that only the Kusile power station be commissioned with abatement technology to achieve all new-plant MES standards, while Medupi be retrofitted with flue-gas desulphurisation (FGD) over time to meet new-plant SO2 limits. FGD retrofits are not proposed for any other plant.
Herbst says most of Eskom’s fleet is able to comply with existing-plant limit, or 100 mg/Nm3, for particulate matter and, of the seven stations that currently do not comply with the existing-plant NOx standards, retrofits to Tutuka, Matla and Majuba will ensure new-plant standards for NOx are met.
Full compliance with the emission limits, Eskom argues, would have many socioeconomic implications, including for electricity tariffs. “If the additional costs are not allowed, Eskom’s financial health will further deteriorate and the ability to raise funding for these environmental projects would be limited.”
Eskom’s application for a suspension, alternative limits and/or postponement of compliance with the MES has already met with strong resistance from the Life After Coal campaign, which represents several environmental rights groups.
Instead of further delaying MES compliance the campaign has call for urgent enforcement action against Eskom as a result of its noncompliance with its atmospheric emission licence limits across several power stations.
The Life After Coal campaign argues that, if Eskom’s coal plants cannot comply with South Africa’s “already-weak MES, they should be decommissioned urgently, and an inclusive, transparent, and just transition plan put in place to support workers and their families”.