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Data as of 2026-09-20
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Built 2026-09-21 (21 September 2026)

Bulgaria Demand Forecast Accuracy: Error, Bias and Worst Miss, 23 August to 20 September 2026

The day-ahead demand forecast for Bulgaria was off by 4.5% on average (mean absolute percentage error) over 683 hours from 23 August to 20 September 2026, and 77% of hours landed within 5% of the reading. Its bias was +3.2%: it ran high on average, an over forecast. The largest miss was 1,547 MW (57.3%) too high at 29 Aug 2026, 12:00 EEST (UTC+03:00). Dates and times are local (Europe/Sofia).

Key Facts

  • The day-ahead demand forecast for Bulgaria was off by 4.5% on average (mean absolute percentage error) over 683 hours from 23 August to 20 September 2026, and 77% of hours landed within 5% of the reading. Its bias was +3.2%: it ran high on average, an over forecast. The largest miss was 1,547 MW (57.3%) too high at 29 Aug 2026, 12:00 EEST (UTC+03:00).
  • Across 47 European bidding zones ranked by average error over their own latest 30 day windows, Bulgaria came 30 (1 is the smallest error).
  • On average the forecast differed from reported demand by 155 MW, against average demand of 3,707 MW.
  • The forecast was above reported demand in 68% of compared hours.

Forecast Error at a Glance

683 hours from 23 August to 20 September 2026
Average error4.5%
Bias+3.2%
Hours within 5%77%
Worst miss1,547 MW

Average error is the mean absolute percentage gap between the forecast and reported demand. Bias is the signed mean (+104 MW per hour on average): the forecast ran high on average, an over forecast. The worst miss was 1,547 MW (57.3%) too high at 29 Aug 2026, 12:00 EEST (UTC+03:00): forecast 4,248 MW, reported 2,701 MW.

Source: ENTSO-E Transparency Platform (transparency.entsoe.eu), CC BY 4.0. Aggregated and converted by World Power Monitor; ENTSO-E does not endorse this site. (ENTSO-E Terms of Use plus CC BY 4.0 for listed data items) Data as of 2026-09-20. Accuracy is computed by World Power Monitor from the operator's hourly forecast and reported demand.

Forecast and Reported Demand, Last 7 Days

Local time, to 20 Sept 2026, 10:00 EEST (UTC+03:00)
Bulgaria day-ahead demand forecast and reported demand by hour Hourly reported demand and the day-ahead forecast for Bulgaria over the last 7 days of the window, to 20 Sept 2026, 10:00 EEST (UTC+03:00). Gaps are hours with a missing, zero or implausible report. 0 1,250 2,500 3,750 5,000 13 Sept, 11:0014 Sept, 11:0015 Sept, 11:0016 Sept, 11:0017 Sept, 11:0018 Sept, 11:0019 Sept, 11:00
Hourly reported demand and the day-ahead forecast for Bulgaria over the last 7 days of the window, to 20 Sept 2026, 10:00 EEST (UTC+03:00). Gaps are hours with a missing, zero or implausible report.
Data to 2026-09-20
Bulgaria day-ahead demand forecast and reported demand by hour
Local hourReported demandDay-ahead forecast
13 Sept, 11:003,904 MW3,800 MW
13 Sept, 12:003,942 MW3,885 MW
13 Sept, 13:003,835 MW3,876 MW
13 Sept, 14:003,763 MW3,866 MW
13 Sept, 15:003,710 MW3,836 MW
13 Sept, 16:003,716 MW3,877 MW
13 Sept, 17:003,787 MW4,008 MW
13 Sept, 18:003,857 MW4,040 MW
13 Sept, 19:003,981 MW4,111 MW
13 Sept, 20:004,068 MW4,204 MW
13 Sept, 21:003,856 MW4,010 MW
13 Sept, 22:003,613 MW3,782 MW
13 Sept, 23:003,411 MW3,545 MW
14 Sept, 00:003,130 MW3,173 MW
14 Sept, 01:002,941 MW2,992 MW
14 Sept, 02:002,848 MW2,898 MW
14 Sept, 03:002,813 MW2,846 MW
14 Sept, 04:002,824 MW2,832 MW
14 Sept, 05:002,945 MW2,864 MW
14 Sept, 06:003,314 MW3,051 MW
14 Sept, 07:003,599 MW3,294 MW
14 Sept, 08:003,825 MW3,646 MW
14 Sept, 09:003,918 MW3,914 MW
14 Sept, 10:003,903 MW4,049 MW
14 Sept, 11:003,932 MW4,131 MW
14 Sept, 12:003,907 MW4,167 MW
14 Sept, 13:003,949 MW4,229 MW
14 Sept, 14:003,925 MW4,150 MW
14 Sept, 15:003,930 MW4,010 MW
14 Sept, 16:003,949 MW4,039 MW
14 Sept, 17:003,967 MW4,097 MW
14 Sept, 18:004,055 MW4,114 MW
14 Sept, 19:004,210 MW4,136 MW
14 Sept, 20:004,313 MW4,193 MW
14 Sept, 21:004,068 MW4,012 MW
14 Sept, 22:003,794 MW3,800 MW
14 Sept, 23:003,525 MW3,591 MW
15 Sept, 00:003,211 MW3,191 MW
15 Sept, 01:003,010 MW3,014 MW
15 Sept, 02:002,942 MW2,927 MW
15 Sept, 03:002,871 MW2,890 MW
15 Sept, 04:002,875 MW2,887 MW
15 Sept, 05:002,987 MW2,995 MW
15 Sept, 06:003,375 MW3,289 MW
15 Sept, 07:003,699 MW3,561 MW
15 Sept, 08:003,933 MW3,806 MW
15 Sept, 09:003,926 MW3,898 MW
15 Sept, 10:003,861 MW3,915 MW
15 Sept, 11:003,911 MW3,976 MW
15 Sept, 12:003,946 MW3,994 MW
15 Sept, 13:004,033 MW4,101 MW
15 Sept, 14:004,016 MW3,861 MW
15 Sept, 15:003,977 MW3,944 MW
15 Sept, 16:003,948 MW3,930 MW
15 Sept, 17:003,942 MW4,006 MW
15 Sept, 18:004,009 MW4,117 MW
15 Sept, 19:004,189 MW4,304 MW
15 Sept, 20:004,215 MW4,374 MW
15 Sept, 21:003,979 MW4,096 MW
15 Sept, 22:003,716 MW3,787 MW
15 Sept, 23:003,450 MW3,498 MW
16 Sept, 00:003,182 MW3,130 MW
16 Sept, 01:002,990 MW2,987 MW
16 Sept, 02:002,884 MW2,918 MW
16 Sept, 03:002,863 MW2,889 MW
16 Sept, 04:002,885 MW2,891 MW
16 Sept, 05:003,004 MW3,007 MW
16 Sept, 06:003,433 MW3,324 MW
16 Sept, 07:003,725 MW3,615 MW
16 Sept, 08:003,901 MW3,865 MW
16 Sept, 09:003,950 MW3,957 MW
16 Sept, 10:003,930 MW3,967 MW
16 Sept, 11:003,934 MW4,024 MW
16 Sept, 12:003,940 MW4,038 MW
16 Sept, 13:003,999 MW4,146 MW
16 Sept, 14:003,989 MW4,130 MW
16 Sept, 15:003,977 MW4,173 MW
16 Sept, 16:003,951 MW4,183 MW
16 Sept, 17:003,940 MW4,210 MW
16 Sept, 18:004,023 MW4,258 MW
16 Sept, 19:004,224 MW4,354 MW
16 Sept, 20:004,272 MW4,386 MW
16 Sept, 21:004,020 MW4,125 MW
16 Sept, 22:003,766 MW3,830 MW
16 Sept, 23:003,491 MW3,557 MW
17 Sept, 00:003,205 MW3,229 MW
17 Sept, 01:003,011 MW3,022 MW
17 Sept, 02:002,920 MW2,929 MW
17 Sept, 03:002,885 MW2,880 MW
17 Sept, 04:002,885 MW2,883 MW
17 Sept, 05:003,011 MW2,993 MW
17 Sept, 06:003,440 MW3,311 MW
17 Sept, 07:003,730 MW3,596 MW
17 Sept, 08:003,937 MW3,834 MW
17 Sept, 09:003,972 MW3,903 MW
17 Sept, 10:003,926 MW3,898 MW
17 Sept, 11:003,925 MW3,951 MW
17 Sept, 12:003,913 MW3,969 MW
17 Sept, 13:003,948 MW4,068 MW
17 Sept, 14:003,963 MW3,982 MW
17 Sept, 15:003,930 MW4,002 MW
17 Sept, 16:003,934 MW4,001 MW
17 Sept, 17:003,962 MW4,019 MW
17 Sept, 18:004,034 MW4,073 MW
17 Sept, 19:004,205 MW4,195 MW
17 Sept, 20:004,244 MW4,225 MW
17 Sept, 21:004,000 MW3,986 MW
17 Sept, 22:003,734 MW3,716 MW
17 Sept, 23:003,467 MW3,462 MW
18 Sept, 00:003,143 MW3,198 MW
18 Sept, 01:002,960 MW3,003 MW
18 Sept, 02:002,860 MW2,913 MW
18 Sept, 03:002,828 MW2,871 MW
18 Sept, 04:002,832 MW2,876 MW
18 Sept, 05:002,947 MW2,986 MW
18 Sept, 06:003,362 MW3,316 MW
18 Sept, 07:003,589 MW3,597 MW
18 Sept, 08:003,469 MW3,820 MW
18 Sept, 09:003,145 MW3,885 MW
18 Sept, 10:002,820 MW3,877 MW
18 Sept, 11:002,643 MW3,922 MW
18 Sept, 12:002,544 MW3,938 MW
18 Sept, 13:002,651 MW4,029 MW
18 Sept, 14:002,693 MW3,974 MW
18 Sept, 15:002,761 MW3,986 MW
18 Sept, 16:002,999 MW3,980 MW
18 Sept, 17:003,375 MW3,990 MW
18 Sept, 18:003,782 MW4,045 MW
18 Sept, 19:003,964 MW4,170 MW
18 Sept, 20:003,899 MW4,201 MW
18 Sept, 21:003,671 MW3,965 MW
18 Sept, 22:003,437 MW3,705 MW
18 Sept, 23:003,263 MW3,454 MW
19 Sept, 00:003,094 MW3,183 MW
19 Sept, 01:002,902 MW3,004 MW
19 Sept, 02:002,801 MW2,903 MW
19 Sept, 03:002,745 MW2,850 MW
19 Sept, 04:002,731 MW2,818 MW
19 Sept, 05:002,780 MW2,842 MW
19 Sept, 06:002,962 MW2,955 MW
19 Sept, 07:003,063 MW3,085 MW
19 Sept, 08:003,085 MW3,268 MW
19 Sept, 09:002,929 MW3,422 MW
19 Sept, 10:002,919 MW3,503 MW
19 Sept, 11:002,946 MW3,565 MW
19 Sept, 12:003,072 MW3,633 MW
19 Sept, 13:003,062 MW3,664 MW
19 Sept, 14:003,019 MW3,647 MW
19 Sept, 15:003,057 MW3,629 MW
19 Sept, 16:003,038 MW3,604 MW
19 Sept, 17:003,298 MW3,724 MW
19 Sept, 18:003,594 MW3,908 MW
19 Sept, 19:003,726 MW4,050 MW
19 Sept, 20:003,680 MW3,996 MW
19 Sept, 21:003,473 MW3,766 MW
19 Sept, 22:003,360 MW3,559 MW
19 Sept, 23:003,184 MW3,363 MW
20 Sept, 00:002,991 MW3,124 MW
20 Sept, 01:002,834 MW2,946 MW
20 Sept, 02:002,743 MW2,828 MW
20 Sept, 03:002,687 MW2,785 MW
20 Sept, 04:002,787 MW2,745 MW
20 Sept, 05:002,704 MW2,765 MW
20 Sept, 06:002,851 MW2,884 MW
20 Sept, 07:002,944 MW3,027 MW
20 Sept, 08:002,954 MW3,293 MW
20 Sept, 09:002,897 MW3,506 MW
20 Sept, 10:002,967 MW3,622 MW

Assumptions

  • Only hours with both a forecast and a positive demand reading count (683 of 683 hours in the window). Missing and zero values, and readings under 30% or over 3 times the grid's own median for the window, are treated as reporting faults and left out.
  • Error is (forecast minus reported demand) divided by reported demand; average error uses absolute values so high and low misses do not cancel. Bias keeps the sign and does cancel.
  • Reported demand is preliminary and may be revised. A 30 day window is a short sample and one heat wave or holiday can move these figures.
  • European figures are for the ENTSO-E bidding zone named on this page. US and European grids are ranked separately.