Load suspension at Khmelnytska NPP Unit 2 at 760 MW, limited TPP generation and short-term curtailments of RES, as well as electricity imports from the Russian Federation and Belarus in the integrated power system (IPS) of Ukraine are due to a significant decrease in electricity consumption in 2019. This decrease, in turn, is caused by an abnormally warm ambient temperature that is not typical for November average temperatures.
The statistics cites the long-term average ambient temperature for early November at +5.5°C, with an average daily consumption of 435 million kWh. On November 1-12, 2019, the figures were +13.5°C and 405 million kWh, respectively.
“The dispatcher suspended the load of the second power unit of the Khmelnytska NPP, connected to the grid on November 11, at 760 MW. Electricity imports from Russia and Belarus have been limited for seven consecutive days starting from November 6 and do not exceed 50 MW at nighttime. Due to considerably warm weather, the grid cannot take in the high level of NPP base capacity (during November 1-10 it was 50-55% in the power mix, and on November 11 it reached 61%). In order to take in the full capacity of KhNPP Unit 2 (1000 MW), at least three thermal power plants would have to be stopped at night. In doing so, we would lose the ability to cover the peak load. In the previous model of the market, this was called “incompatible regime”, and SE Energorynok would then limit the capacity of the NPP in daily load scheduling,” Vitaliy Zaichenko, Chief Dispatcher of NPC Ukrenergo explained.
There is also an issue of consistent overstatement of electricity purchases/sales by suppliers – 20% on average, as well as low level of accuracy of forecasting SPP and WPP generation (considering that they are not liable for their imbalances). The above are added up with Energoatom’s generation, which the company is not able to sell in the full volume at the day-ahead market. As a result, daily physical power surplus is about 2 GW.
In such circumstance, dispatcher’s daily corrective actions are a prerequisite for the power system’s stable operation.
We would like to stress that in its operations NPC Ukrenergo is governed solely by the current legislation, which stipulates that ensuring the grid’s operational security the is the highest priority of the transmission system operator. All curtailments of generation are done in accordance with the ranking of unloading, and after it is exhausted, TPP units are disconnected for balancing the power system with at least one generation unit left in operation at each power plant.
Ukrenergo urges energy experts and journalists to refrain from speculative and unsubstantiated comments about the necessity of restricting one or another type of generation.