For the time being, country’s power consumption has not been disturbed by the quarantine imposed due to COVID-19. There is even a slight, albeit insignificant, increase has been observed compared to previous years’ data.
In the last two weeks of March 2020 (16th-29th March), net domestic electricity consumption was 1513 GWh. For the last five years (2015-2019), average electricity consumption had been 1496 GWh which means that March 2020 shows an increase of 1.18%.
Significantly more dramatic dynamics are observed when comparing consumption individually for the two weeks of March. Contrary to expectations, consumption in the second quarantine week (23th to 29th March) was 7.34% higher than the first week, and 5.23% higher than the average power consumption in the same week of the last five years. Bulgaria’s situation looks better than that in Italy, France, the UK and Germany where by March 18 electricity consumption drop against a five-year average value was between 5% and 13%. (ICIS: European power prices will on average decline by 9% because of COVID-19).
Fig. 1 Power consumption alterations in Bulgaria and some EU countries (Source: ENTSO-E и ICIS)
At this early stage any estimates should be made with caution since Member States apply different quarantine schemes, have different industry and service structure/vulnerability and the impact of lower temperatures. The correction due to lower temperatures, respectively – increased demand in particular by households, will most probably prompt certain decline in consumption.
Both for Bulgaria and EU, the picture is expected to become clearer by the end of April.
Supply structure
For the two weeks of March (16th-29th), Kosloduy NPP has been operating continuously at 2111-2164 MWh, standing as the traditional principal supplier of power base load for the electricity system.
Secondly, lignite thermal power plants have been operating also continuously at 1400 MWh to 2416 MWh thus exercising two important functions: first, power base load supply, together with Kozloduy NPP, and secondly, dynamic operations in a sub-peak regime that is of key importance for power system flexibility and security. Then, there are the large-scale HPP, standing at the top point of the load curve, operating at a capacity of 8 MWh to 902 MWh.
In the two-week period, among the non-dispatchable (must-run) power generation, the main contributors to load coverage are wind power plants with a capacity in the range of 2 to 727 MW, 124 MWh to 261 MWh from small-scale HPP operating on running water, 0 MWh to 903 MWh from PV power plants and 311 MWh to 360 MWh from gas-fired power plants (co-generation).
Diurnal load profile of the electricity system
The figure bellow shows the diurnal load profile on a weekday, namely, the last Thursday of March in 2019 and 2020 (28th March 2019 and 26th March 2020).
All through a 24-hour period, the 2020 system load ran higher than that in 2019. Between 8 a.m. and 7 p.m., 2020 load remained rather constant, with maximum values indicating high business activity. Within the same time span, system load in 2019 was about 20% lower.
Fig. 2 Weekday load profile; last Thursday of March (Source: ENTSO-E)
Another diagram showing load profile over a weekend day is given for comparison; it shows the last Saturday of March, 28th March 2020 and 30th March 2019, respectively.
These curves show identical courses with respect to values and behavior which allows concluding that at least in terms of electricity consumption, the lifestyle has not changed for the time being. Loads differences observed between the two charts within the active time period speaks, yet again, about a sustained business activity.
Fig. 3 Weekend day load profile; last Saturday of March (Source: ENTSO-E)
Methodology
ENTSO-E data on actual hourly loads and generation structure are used in the calculations. As per the definition, the Actual total load (including losses, without energy storage) = net generation – export + import – absorbed energy (PSHPPs’ consumption).
