Belgium Demand Forecast Accuracy: Error, Bias and Worst Miss, 30 September to 28 October 2026

The day-ahead demand forecast for Belgium was off by 2.5% on average (mean absolute percentage error) over 685 hours from 30 September to 28 October 2026, and 90% of hours landed within 5% of the reading. Its bias was -1.4%: it ran low on average, an under forecast. The largest miss was 1,367 MW (11.3%) too low at 22 Oct 2026, 13:00 CEST (UTC+02:00). Dates and times are local (Europe/Brussels).

Key Facts

The day-ahead demand forecast for Belgium was off by 2.5% on average (mean absolute percentage error) over 685 hours from 30 September to 28 October 2026, and 90% of hours landed within 5% of the reading. Its bias was -1.4%: it ran low on average, an under forecast. The largest miss was 1,367 MW (11.3%) too low at 22 Oct 2026, 13:00 CEST (UTC+02:00).
Across 47 European bidding zones ranked by average error over their own latest 30 day windows, Belgium came 18 (1 is the smallest error).
On average the forecast differed from reported demand by 242 MW, against average demand of 9,321 MW.
The forecast was above reported demand in 30% of compared hours.

Forecast Error at a Glance

685 hours from 30 September to 28 October 2026

Average error2.5%

Bias-1.4%

Hours within 5%90%

Worst miss1,367 MW

Average error is the mean absolute percentage gap between the forecast and reported demand. Bias is the signed mean (-135 MW per hour on average): the forecast ran low on average, an under forecast. The worst miss was 1,367 MW (11.3%) too low at 22 Oct 2026, 13:00 CEST (UTC+02:00): forecast 10,733 MW, reported 12,100 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 2026-10-28. 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 28 Oct 2026, 12:00 CET (UTC+01:00)

Hourly reported demand and the day-ahead forecast for Belgium over the last 7 days of the window, to 28 Oct 2026, 12:00 CET (UTC+01:00). Gaps are hours with a missing, zero or implausible report.

Data to 2026-10-28

Show the data table (168 rows)

Local hour	Reported demand	Day-ahead forecast
21 Oct, 14:00	11,091 MW	11,335 MW
21 Oct, 15:00	10,832 MW	11,056 MW
21 Oct, 16:00	10,718 MW	10,700 MW
21 Oct, 17:00	10,830 MW	10,501 MW
21 Oct, 18:00	10,701 MW	10,374 MW
21 Oct, 19:00	10,611 MW	10,430 MW
21 Oct, 20:00	10,143 MW	10,020 MW
21 Oct, 21:00	9,486 MW	9,625 MW
21 Oct, 22:00	9,239 MW	9,244 MW
21 Oct, 23:00	8,877 MW	8,819 MW
22 Oct, 00:00	8,442 MW	8,328 MW
22 Oct, 01:00	8,197 MW	8,021 MW
22 Oct, 02:00	7,975 MW	7,997 MW
22 Oct, 03:00	7,979 MW	7,856 MW
22 Oct, 04:00	8,147 MW	7,797 MW
22 Oct, 05:00	8,406 MW	8,128 MW
22 Oct, 06:00	9,225 MW	8,942 MW
22 Oct, 07:00	10,126 MW	10,009 MW
22 Oct, 08:00	10,796 MW	10,612 MW
22 Oct, 09:00	11,385 MW	11,143 MW
22 Oct, 10:00	11,485 MW	11,063 MW
22 Oct, 11:00	11,983 MW	11,227 MW
22 Oct, 12:00	12,137 MW	11,103 MW
22 Oct, 13:00	12,100 MW	10,733 MW
22 Oct, 14:00	11,712 MW	10,607 MW
22 Oct, 15:00	11,237 MW	10,650 MW
22 Oct, 16:00	10,782 MW	10,583 MW
22 Oct, 17:00	10,918 MW	10,626 MW
22 Oct, 18:00	10,659 MW	10,626 MW
22 Oct, 19:00	10,592 MW	10,669 MW
22 Oct, 20:00	10,411 MW	10,217 MW
22 Oct, 21:00	9,890 MW	9,664 MW
22 Oct, 22:00	9,406 MW	9,289 MW
22 Oct, 23:00	9,036 MW	8,836 MW
23 Oct, 00:00	8,468 MW	8,448 MW
23 Oct, 01:00	8,213 MW	8,129 MW
23 Oct, 02:00	7,911 MW	7,855 MW
23 Oct, 03:00	7,867 MW	7,724 MW
23 Oct, 04:00	7,848 MW	7,791 MW
23 Oct, 05:00	8,236 MW	8,123 MW
23 Oct, 06:00	9,066 MW	9,066 MW
23 Oct, 07:00	9,914 MW	9,970 MW
23 Oct, 08:00	10,529 MW	10,606 MW
23 Oct, 09:00	11,080 MW	11,112 MW
23 Oct, 10:00	11,323 MW	11,277 MW
23 Oct, 11:00	11,353 MW	11,465 MW
23 Oct, 12:00	11,237 MW	11,183 MW
23 Oct, 13:00	11,467 MW	11,311 MW
23 Oct, 14:00	11,159 MW	11,005 MW
23 Oct, 15:00	10,694 MW	10,647 MW
23 Oct, 16:00	10,496 MW	10,264 MW
23 Oct, 17:00	10,911 MW	10,337 MW
23 Oct, 18:00	10,901 MW	10,410 MW
23 Oct, 19:00	10,633 MW	10,288 MW
23 Oct, 20:00	10,223 MW	9,824 MW
23 Oct, 21:00	9,603 MW	9,420 MW
23 Oct, 22:00	9,113 MW	9,135 MW
23 Oct, 23:00	8,838 MW	8,811 MW
24 Oct, 00:00	8,324 MW	8,379 MW
24 Oct, 01:00	8,054 MW	8,017 MW
24 Oct, 02:00	7,818 MW	7,665 MW
24 Oct, 03:00	7,602 MW	7,504 MW
24 Oct, 04:00	7,527 MW	7,471 MW
24 Oct, 05:00	7,458 MW	7,587 MW
24 Oct, 06:00	7,886 MW	7,723 MW
24 Oct, 07:00	8,300 MW	8,283 MW
24 Oct, 08:00	8,840 MW	8,787 MW
24 Oct, 09:00	9,517 MW	9,378 MW
24 Oct, 10:00	10,200 MW	9,928 MW
24 Oct, 11:00	10,591 MW	10,192 MW
24 Oct, 12:00	10,815 MW	10,085 MW
24 Oct, 13:00	10,186 MW	10,039 MW
24 Oct, 14:00	9,495 MW	9,785 MW
24 Oct, 15:00	9,153 MW	9,248 MW
24 Oct, 16:00	9,134 MW	9,071 MW
24 Oct, 17:00	9,395 MW	9,106 MW
24 Oct, 18:00	9,661 MW	9,262 MW
24 Oct, 19:00	9,680 MW	9,276 MW
24 Oct, 20:00	9,358 MW	9,112 MW
24 Oct, 21:00	8,981 MW	8,772 MW
24 Oct, 22:00	8,756 MW	8,556 MW
24 Oct, 23:00	8,485 MW	8,187 MW
25 Oct, 00:00	7,808 MW	7,708 MW
25 Oct, 01:00	7,522 MW	7,452 MW
25 Oct, 02:00	7,304 MW	7,214 MW
25 Oct, 02:00	7,142 MW	7,359 MW
25 Oct, 03:00	7,056 MW	7,229 MW
25 Oct, 04:00	7,014 MW	7,201 MW
25 Oct, 05:00	7,161 MW	7,240 MW
25 Oct, 06:00	7,581 MW	7,623 MW
25 Oct, 07:00	7,808 MW	7,849 MW
25 Oct, 08:00	8,590 MW	8,065 MW
25 Oct, 09:00	9,229 MW	8,429 MW
25 Oct, 10:00	9,465 MW	9,054 MW
25 Oct, 11:00	9,939 MW	9,171 MW
25 Oct, 12:00	9,725 MW	9,517 MW
25 Oct, 13:00	9,358 MW	9,441 MW
25 Oct, 14:00	8,995 MW	9,106 MW
25 Oct, 15:00	8,833 MW	8,662 MW
25 Oct, 16:00	8,763 MW	8,627 MW
25 Oct, 17:00	9,239 MW	8,839 MW
25 Oct, 18:00	9,786 MW	9,335 MW
25 Oct, 19:00	9,690 MW	9,426 MW
25 Oct, 20:00	9,310 MW	9,124 MW
25 Oct, 21:00	9,095 MW	8,899 MW
25 Oct, 22:00	8,775 MW	8,518 MW
25 Oct, 23:00	8,457 MW	8,194 MW
26 Oct, 00:00	8,194 MW	7,700 MW
26 Oct, 01:00	7,953 MW	7,590 MW
26 Oct, 02:00	7,720 MW	7,384 MW
26 Oct, 03:00	7,731 MW	7,377 MW
26 Oct, 04:00	7,665 MW	7,397 MW
26 Oct, 05:00	8,131 MW	7,760 MW
26 Oct, 06:00	9,056 MW	8,829 MW
26 Oct, 07:00	9,525 MW	9,925 MW
26 Oct, 08:00	10,508 MW	10,600 MW
26 Oct, 09:00	11,375 MW	11,057 MW
26 Oct, 10:00	11,650 MW	11,282 MW
26 Oct, 11:00	11,167 MW	11,507 MW
26 Oct, 12:00	11,144 MW	11,158 MW
26 Oct, 13:00	11,244 MW	11,020 MW
26 Oct, 14:00	10,888 MW	10,621 MW
26 Oct, 15:00	10,500 MW	10,398 MW
26 Oct, 16:00	10,243 MW	10,295 MW
26 Oct, 17:00	10,582 MW	10,426 MW
26 Oct, 18:00	10,884 MW	10,772 MW
26 Oct, 19:00	10,640 MW	10,693 MW
26 Oct, 20:00	10,168 MW	9,997 MW
26 Oct, 21:00	9,549 MW	9,320 MW
26 Oct, 22:00	9,143 MW	9,019 MW
26 Oct, 23:00	8,975 MW	8,536 MW
27 Oct, 00:00	8,361 MW	7,920 MW
27 Oct, 01:00	8,034 MW	7,855 MW
27 Oct, 02:00	8,041 MW	7,696 MW
27 Oct, 03:00	7,937 MW	7,638 MW
27 Oct, 04:00	7,992 MW	7,716 MW
27 Oct, 05:00	8,216 MW	8,027 MW
27 Oct, 06:00	9,094 MW	8,933 MW
27 Oct, 07:00	9,801 MW	10,057 MW
27 Oct, 08:00	10,753 MW	10,613 MW
27 Oct, 09:00	11,387 MW	10,935 MW
27 Oct, 10:00	11,454 MW	10,909 MW
27 Oct, 11:00	11,464 MW	11,062 MW
27 Oct, 12:00	11,239 MW	10,978 MW
27 Oct, 13:00	10,944 MW	11,003 MW
27 Oct, 14:00	10,480 MW	10,901 MW
27 Oct, 15:00	10,445 MW	10,532 MW
27 Oct, 16:00	10,383 MW	10,471 MW
27 Oct, 17:00	10,606 MW	10,524 MW
27 Oct, 18:00	10,947 MW	10,743 MW
27 Oct, 19:00	10,652 MW	10,631 MW
27 Oct, 20:00	10,175 MW	10,032 MW
27 Oct, 21:00	9,461 MW	9,550 MW
27 Oct, 22:00	9,041 MW	9,187 MW
27 Oct, 23:00	8,699 MW	8,825 MW
28 Oct, 00:00	8,230 MW	8,196 MW
28 Oct, 01:00	7,922 MW	7,968 MW
28 Oct, 02:00	7,776 MW	7,745 MW
28 Oct, 03:00	7,661 MW	7,573 MW
28 Oct, 04:00	7,730 MW	7,594 MW
28 Oct, 05:00	8,154 MW	7,937 MW
28 Oct, 06:00	8,997 MW	8,856 MW
28 Oct, 07:00	9,748 MW	9,752 MW
28 Oct, 08:00	10,673 MW	10,362 MW
28 Oct, 09:00	11,319 MW	10,656 MW
28 Oct, 10:00	11,626 MW	10,867 MW
28 Oct, 11:00	11,833 MW	11,091 MW
28 Oct, 12:00	11,706 MW	10,824 MW

Assumptions

Only hours with both a forecast and a positive demand reading count (685 of 685 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.

Cite this page

APA 7

World Power Monitor. (2026). Belgium Demand Forecast Accuracy: Error, Bias and Worst Miss. https://worldpowermonitor.com/forecast-accuracy/be/

Plain text

World Power Monitor. Belgium Demand Forecast Accuracy: Error, Bias and Worst Miss. Data as of 2026-10-28. Data from ENTSO-E Transparency Platform. https://worldpowermonitor.com/forecast-accuracy/be/

BibTeX

@misc{wpm_forecast_accuracy_be_2026,
  title = {{Belgium Demand Forecast Accuracy: Error, Bias and Worst Miss}},
  author = {{World Power Monitor}},
  year = {2026},
  note = {Data as of 2026-10-28. Data from ENTSO-E Transparency Platform.},
  url = {https://worldpowermonitor.com/forecast-accuracy/be/}
}

Permalink: https://worldpowermonitor.com/forecast-accuracy/be/

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Belgium Demand Forecast Accuracy: Error, Bias and Worst Miss, 30 September to 28 October 2026

Key Facts

Forecast Error at a Glance

Forecast and Reported Demand, Last 7 Days

Assumptions

Related