During the night peak final week, Eskom utilised its diesel-burning open cycle gasoline generators (OCGTs) for all however one of many 24 hours that made up the time of day the place demand is biggest.
Public knowledge from the utility exhibits that Eskom made use of its OCGTs between (not less than) 4pm and 10pm each day between Tuesday and Friday (Monday was a public vacation, but it nonetheless used these generators between 5pm and 9pm).
In addition, it known as on unbiased energy producer (IPP) operators on the Avon and Dedisa peaking energy vegetation to function their diesel generators for a similar 23 of 24 peak hours (the one hour neither Eskom nor the IPP OCGTs have been used was at 9pm on Friday, when demand is much decrease than on different weekdays).
Eskom will argue, as COO Jan Oberholzer did in March, that: “They were always intended to be used … early in the morning and late in the afternoon when there is a lot of demand on the country.”
But it’s apparent that they weren’t supposed for use for virtually each single hour of peak each single weekday.
It additionally used the OCGTs pretty extensively within the morning peak final week. This as Eskom carried out Stage 2 load shedding at 5pm on Tuesday and stated this is able to proceed to Monday. It decreased this to Stage 1 on Friday evening at 10pm and suspended load shedding altogether at 12 noon on Saturday.
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The utilization of the OCGTs final week equates to lots of of tens of millions of rands of diesel, however usefully its pumped storage schemes had recovered sufficiently for these to have the ability to complement base load energy between 6am and 8pm every day as a result of poor-performing coal fleet.
On Thursday evening at 6pm, the Eskom and IPP OCGTs supplied 2 854 megawatts (MW) to the grid, equal to the whole quantity Eskom imports from the Cahora Bassa hydroelectric plant plus its whole regular era from the Koeberg Nuclear Power Station (the place unit two stays offline till June for refuelling and upkeep).
Regulator Nersa has authorised a load issue for OCGTs of three% for 2022/23, lower than half of what Eskom had initially requested (7%). This equated to roughly R3 billion in March (diesel costs are up steeply since then).
So far, the load issue for Eskom’s personal OCGTs is at 15.91% for the primary 5 weeks of its monetary yr. For IPPs, the load issue just isn’t a lot decrease than this, at 11.03%. Of course, Eskom’s monetary yr nonetheless has an extended method to run however it’s optimistic to see a state of affairs the place Eskom achieves a load issue for the OCGTs of lower than 10% (roughly the determine from its final monetary yr).
In April, it used OCGTs (its personal and people run by IPPs) to generate 327 gigawatt hours (GWh) of electrical energy. This is a 52% improve on the 215.9GWh in April 2021.
A situation shared publicly in its most up-to-date system standing and outlook briefing (in January) envisaged 61 days of load shedding between April 1 and August 31. At that stage, this was the worst case which noticed a most of Stage 2 with common unplanned availability of 13 000MW throughout the interval.
Spike in diesel prices
In this situation, it estimated it could use R3.4 billion in diesel at its personal OCGTs in addition to these run by the IPPs.
The spend is nearly sure to be far worse than this for 2 causes.
One, it’s had a horrible begin to winter with these load components of 15.91% (Eskom’s OCGTs) and 11.03% (IPP OCGTs).
But, extra importantly, diesel costs are up 28% between January and now. Much of this is because of Russia’s invasion of Ukraine which, for a mess of causes, has resulted in a worldwide scarcity of diesel.
Oberholzer advised the media in March that Eskom’s diesel generators value round R700 000 per hour to run. Since then, costs are up an additional 13%, which means these prices are actually roughly R800 000 per hour.
Eskom stated in January that “history has shown that it is not possible to use more than about R1.2 billion of diesel in a month due to the physical limitations of moving the diesel to the OCGT stations”.
But consider that 28% worth improve and the higher restrict is now R1.5 billion.
The solely method to lower this spend is to change the OCGTs to run on gasoline.
But Eskom has been speaking about this virtually since their commissioning round 15 years again. Just a few years in the past, it carried out twin burners to permit these to run on both diesel or liquefied pure gasoline (LNG). That’s about so far as it has progressed.
While liquefied petroleum gasoline (LPG) costs are additionally up considerably, this can be a cheaper gas supply than diesel. Oberholzer stated in March Eskom would go to market “soon” to ask the provision of gasoline for these vegetation in addition to the previous coal-fired Komati Power Station in Mpumalanga (which it can repurpose to run on gasoline).
The spike in international diesel costs could focus Eskom’s efforts slightly extra intently.
That, and the truth that its “extreme” worst-case situation for winter is now as a lot as 100 days of load shedding. That’s a giant soar from 61.
Listen to Robert Maake of the Department of Mineral Resources and Energy chatting with Fifi Peters concerning the spike in diesel costs: