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  • On balancing the power system on 18-24 May, 2020


    The second stage of easing the quarantine restrictions in some regions that started on 22 May has not brought in any significant increase in power consumption. Last week, 18-24 May, the average daily consumption on working days increased only by 0.2% to 348.4 million kWh compared to the previous week. However, this is by 2.7% less than for the same period of the previous year (358 million kWh). At the weekend, 23-24 May, the average consumption remained close to the previous weekend – 328 million kWh, that is by 3.3% less than for the same period of the previous year.

    Irregularity of the load schedule (difference between the night off-peak 11.5 – 12 GW and the evening peak hours 16 – 16.5 GW) on working days amounted to 4.4 GW, on weekend – 4 GW.

    RES generation

    Daily solar (SPP) and wind (WPP) power generation oscillated in significant range as before: from 20 million to 38.1 million kWh per day. The peak RES generation on previous week amounted to 38.1 million kWh on 18 May (SPP – 28.7 million kWh, WPP – 9.4 million kWh). Total RES production amounted to 206.6 million kWh (by 8% less than on previous week). There were no dispatch restrictions on WPP and SPP generations.

    On power surplus

    During the last week, daily volumes of undistributed electricity to end-users amounted at average to 40 million kWh. These volumes were sold in balancing market to those participants (producers), which applied for unloading according to market rules (in other words, agreed to resell somebody’s else electricity to their buyers/consumers instead of generating their own).

    NPP generation

    Daily average NPP generation has not changed compared to the previous week, and amounted to 175 million kWh. As of 24 May, from the beginning of the month, NPPs have generated 4.32 billion kWh, that is by 13.4% more than the volumes foreseen in the forecast balance. At the same time, NPP share in total production structure from the beginning of May amounted to more than a half, namely – about 52%.

    Total NPP loading on 18-24 May remained at the same level compared to the previous week, that is 7.3-7.4 GW.

    At 07:52 on 18 May, power unit №1 of Rivne NPP (440 МW) was switched off the grid due to emergency automatic protection as a result of disconnection of main circulation pumps. In order to ensure the loading at 7.3 GW, the capacity of the power unit №3 at Rivne NPP was increased up to 800 МW. In addition, to cover the consumption schedule, HPPs and PSPPs were additionally loaded.

    At 09:10 on 20 May, as reported by SNRIU, due to erroneous actions of the personnel, “turbine trip with bypass” signal occurred at power unit №2 of Khmelnytskyi NPP. As a result, the power unit was automatically unloaded from 700 МW to 350 МW. At 16:00, the loading of the power unit №2 was restored to 700 МW. As a result, on 20 May, the consumption scheduled had to be covered by thermal generation: TPP production was increased to maximum value of 115 million kWh for the week.

    At the same time, at 14:43 on 20 May, power unit №1 (440 МW) of Rivne NPP was connected to the grid with further decrease to the capacity of power unit №3 of Rivne NPP in order to switch it to standby mode at 13:15 on 21 May.

    In order to ensure the loading at 7300 МW, power unit №6 of Zaporizhzhia NPP was connected to the grid after in-line repair had been completed.

    As of 24 May, 10 NPP power units were in operation mode, 4 more power units were shut down for repairing, and 1 unit was switched to standby mode.

    As of 24 May, total NPP loading remains at the same level as it was at the end of the previous week, namely 7300 МW. The reason for this is to ensure the normative level of reserves of 1000 МW at TPPs under reduced daily average consumption (by 4% less comparing to the same period of the previous year) and lack of resource at HPP Dnipro cascade (HPP production reduced by 43% compared to the same period of 2019).

    HPP and TPP generation

    On 18-24 May, HPP power production reduced by 10.2% compared to the previous week (from 102.3 million kWh to 91.9 million kWh). From the beginning of the month, HPPs have generated 327.6 million kWh, that is by 1.1% less than the forecast balance value for May. For 24 days of May, PSPPs have produced 111.4 million kWh (+5% to forecast), and consumed 150 million kWh in the pump mode, that is by 5% more than the forecast value.

    Last week, TPP generation increased by 11.7% (from 658.6 million kWh to 735.6 million kWh). Total TPP power production from the beginning of May amounted to 2.2 billion kWh, that is by 8.9% less than the forecast balance value. TPP share in total production structure amounts to approximately 26%.

    In addition, from 17:00 to 18:00 on 24 May at Burshtyn TPP, there was a violation of power importing schedule due to emergency shutdown of power unit №7 of Burshtyn TPP of over 30 МWh. Ay 17:54, power unit № 7 resumed its operation.

    Ensuring reserves

    The operation modes of the power system remain mostly complicated. Automatic frequency restoration reserve (aFRR) in the IPS trading zone during the week amounted to 20-25% of the need, manual frequency restoration reserve (mFRR) for loading – 84%, and the hourly need for unloading during the week amounted to 60-90% of the need.

    The situation with frequency containment reserve (FCR) has changed. If the week before the last one they were not purchased at all due to the lack of offers from market participants, in the middle of the last week they were ensured by 10%. The service was purchased from Kharkivska TPP-5, which became a participant of the ancillary service market on 14 May.

    Ancillary services for “Burshtyn island” are still not purchased due to the absence of registered suppliers.



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