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

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

The day-ahead demand forecast for Poland was off by 2.1% on average (mean absolute percentage error) over 686 hours from 23 August to 20 September 2026, and 93% of hours landed within 5% of the reading. Its bias was +0.8%: it ran high on average, an over forecast. The largest miss was 1,846 MW (9.7%) too high at 16 Sept 2026, 12:00 CEST (UTC+02:00). Dates and times are local (Europe/Warsaw).

Key Facts

  • The day-ahead demand forecast for Poland was off by 2.1% on average (mean absolute percentage error) over 686 hours from 23 August to 20 September 2026, and 93% of hours landed within 5% of the reading. Its bias was +0.8%: it ran high on average, an over forecast. The largest miss was 1,846 MW (9.7%) too high at 16 Sept 2026, 12:00 CEST (UTC+02:00).
  • Across 47 European bidding zones ranked by average error over their own latest 30 day windows, Poland came 8 (1 is the smallest error).
  • On average the forecast differed from reported demand by 370 MW, against average demand of 17,375 MW.
  • The forecast was above reported demand in 60% of compared hours.

Forecast Error at a Glance

686 hours from 23 August to 20 September 2026
Average error2.1%
Bias+0.8%
Hours within 5%93%
Worst miss1,846 MW

Average error is the mean absolute percentage gap between the forecast and reported demand. Bias is the signed mean (+141 MW per hour on average): the forecast ran high on average, an over forecast. The worst miss was 1,846 MW (9.7%) too high at 16 Sept 2026, 12:00 CEST (UTC+02:00): forecast 20,950 MW, reported 19,104 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, 13:00 CEST (UTC+02:00)
Poland day-ahead demand forecast and reported demand by hour Hourly reported demand and the day-ahead forecast for Poland over the last 7 days of the window, to 20 Sept 2026, 13:00 CEST (UTC+02:00). Gaps are hours with a missing, zero or implausible report. 0 6,250 12,500 18,750 25,000 13 Sept, 14:0014 Sept, 14:0015 Sept, 14:0016 Sept, 14:0017 Sept, 14:0018 Sept, 14:0019 Sept, 14:00
Hourly reported demand and the day-ahead forecast for Poland over the last 7 days of the window, to 20 Sept 2026, 13:00 CEST (UTC+02:00). Gaps are hours with a missing, zero or implausible report.
Data to 2026-09-20
Poland day-ahead demand forecast and reported demand by hour
Local hourReported demandDay-ahead forecast
13 Sept, 14:0015,660 MW16,038 MW
13 Sept, 15:0015,743 MW15,850 MW
13 Sept, 16:0016,076 MW16,088 MW
13 Sept, 17:0016,419 MW16,500 MW
13 Sept, 18:0016,647 MW16,688 MW
13 Sept, 19:0017,467 MW17,213 MW
13 Sept, 20:0017,121 MW17,225 MW
13 Sept, 21:0016,106 MW16,250 MW
13 Sept, 22:0015,334 MW15,225 MW
13 Sept, 23:0014,294 MW14,200 MW
14 Sept, 00:0013,747 MW13,663 MW
14 Sept, 01:0013,268 MW13,300 MW
14 Sept, 02:0013,105 MW13,250 MW
14 Sept, 03:0013,103 MW13,263 MW
14 Sept, 04:0013,683 MW13,713 MW
14 Sept, 05:0014,980 MW14,963 MW
14 Sept, 06:0017,782 MW17,838 MW
14 Sept, 07:0019,281 MW19,625 MW
14 Sept, 08:0020,234 MW20,513 MW
14 Sept, 09:0020,628 MW20,638 MW
14 Sept, 10:0020,457 MW20,763 MW
14 Sept, 11:0020,555 MW21,338 MW
14 Sept, 12:0021,092 MW21,350 MW
14 Sept, 13:0020,759 MW21,050 MW
14 Sept, 14:0020,435 MW20,550 MW
14 Sept, 15:0020,064 MW20,788 MW
14 Sept, 16:0020,159 MW20,938 MW
14 Sept, 17:0020,418 MW20,950 MW
14 Sept, 18:0020,390 MW20,713 MW
14 Sept, 19:0021,118 MW21,038 MW
14 Sept, 20:0020,663 MW20,863 MW
14 Sept, 21:0019,086 MW19,275 MW
14 Sept, 22:0017,814 MW17,713 MW
14 Sept, 23:0016,397 MW16,400 MW
15 Sept, 00:0015,602 MW15,563 MW
15 Sept, 01:0015,047 MW15,025 MW
15 Sept, 02:0014,723 MW14,750 MW
15 Sept, 03:0014,840 MW14,775 MW
15 Sept, 04:0015,246 MW15,188 MW
15 Sept, 05:0016,254 MW16,213 MW
15 Sept, 06:0018,577 MW18,575 MW
15 Sept, 07:0020,086 MW20,138 MW
15 Sept, 08:0020,483 MW20,650 MW
15 Sept, 09:0020,244 MW20,600 MW
15 Sept, 10:0019,912 MW20,563 MW
15 Sept, 11:0019,808 MW21,050 MW
15 Sept, 12:0019,495 MW21,125 MW
15 Sept, 13:0019,283 MW20,825 MW
15 Sept, 14:0019,895 MW20,363 MW
15 Sept, 15:0019,738 MW20,500 MW
15 Sept, 16:0020,265 MW20,750 MW
15 Sept, 17:0020,550 MW20,750 MW
15 Sept, 18:0020,338 MW20,788 MW
15 Sept, 19:0021,047 MW21,088 MW
15 Sept, 20:0020,587 MW20,875 MW
15 Sept, 21:0018,923 MW19,275 MW
15 Sept, 22:0017,581 MW17,800 MW
15 Sept, 23:0016,127 MW16,525 MW
16 Sept, 00:0015,133 MW15,638 MW
16 Sept, 01:0014,556 MW15,050 MW
16 Sept, 02:0014,361 MW14,800 MW
16 Sept, 03:0014,416 MW14,813 MW
16 Sept, 04:0014,719 MW15,175 MW
16 Sept, 05:0015,657 MW16,250 MW
16 Sept, 06:0018,055 MW18,438 MW
16 Sept, 07:0019,391 MW19,950 MW
16 Sept, 08:0019,704 MW20,388 MW
16 Sept, 09:0019,226 MW20,288 MW
16 Sept, 10:0018,618 MW20,113 MW
16 Sept, 11:0018,953 MW20,675 MW
16 Sept, 12:0019,104 MW20,950 MW
16 Sept, 13:0019,627 MW20,788 MW
16 Sept, 14:0019,824 MW20,413 MW
16 Sept, 15:0020,358 MW20,563 MW
16 Sept, 16:0020,739 MW20,850 MW
16 Sept, 17:0020,786 MW20,850 MW
16 Sept, 18:0020,943 MW20,863 MW
16 Sept, 19:0021,685 MW21,238 MW
16 Sept, 20:0021,203 MW20,875 MW
16 Sept, 21:0019,503 MW19,288 MW
16 Sept, 22:0017,887 MW17,850 MW
16 Sept, 23:0016,555 MW16,575 MW
17 Sept, 00:0015,681 MW15,588 MW
17 Sept, 01:0015,169 MW15,000 MW
17 Sept, 02:0014,908 MW14,750 MW
17 Sept, 03:0014,795 MW14,788 MW
17 Sept, 04:0015,206 MW15,275 MW
17 Sept, 05:0016,201 MW16,313 MW
17 Sept, 06:0018,549 MW18,738 MW
17 Sept, 07:0020,015 MW20,413 MW
17 Sept, 08:0020,778 MW20,800 MW
17 Sept, 09:0020,818 MW20,713 MW
17 Sept, 10:0020,307 MW20,725 MW
17 Sept, 11:0020,294 MW21,263 MW
17 Sept, 12:0020,105 MW21,588 MW
17 Sept, 13:0019,803 MW21,425 MW
17 Sept, 14:0020,365 MW21,000 MW
17 Sept, 15:0020,406 MW21,100 MW
17 Sept, 16:0020,189 MW21,100 MW
17 Sept, 17:0020,828 MW20,975 MW
17 Sept, 18:0020,653 MW20,825 MW
17 Sept, 19:0021,261 MW21,388 MW
17 Sept, 20:0020,707 MW20,938 MW
17 Sept, 21:0019,213 MW19,275 MW
17 Sept, 22:0017,566 MW17,875 MW
17 Sept, 23:0016,167 MW16,575 MW
18 Sept, 00:0015,342 MW15,538 MW
18 Sept, 01:0014,763 MW14,950 MW
18 Sept, 02:0014,427 MW14,700 MW
18 Sept, 03:0014,385 MW14,738 MW
18 Sept, 04:0014,726 MW15,188 MW
18 Sept, 05:0015,799 MW16,213 MW
18 Sept, 06:0018,055 MW18,513 MW
18 Sept, 07:0019,505 MW20,138 MW
18 Sept, 08:0020,057 MW20,550 MW
18 Sept, 09:0019,674 MW20,463 MW
18 Sept, 10:0018,939 MW20,213 MW
18 Sept, 11:0019,214 MW20,400 MW
18 Sept, 12:0019,431 MW20,550 MW
18 Sept, 13:0019,304 MW20,463 MW
18 Sept, 14:0019,309 MW20,075 MW
18 Sept, 15:0019,858 MW20,225 MW
18 Sept, 16:0020,295 MW20,550 MW
18 Sept, 17:0020,465 MW20,500 MW
18 Sept, 18:0020,233 MW20,500 MW
18 Sept, 19:0020,595 MW20,950 MW
18 Sept, 20:0020,035 MW20,650 MW
18 Sept, 21:0018,504 MW19,063 MW
18 Sept, 22:0017,031 MW17,713 MW
18 Sept, 23:0015,849 MW16,413 MW
19 Sept, 00:0015,070 MW15,500 MW
19 Sept, 01:0014,495 MW14,825 MW
19 Sept, 02:0014,054 MW14,488 MW
19 Sept, 03:0014,026 MW14,425 MW
19 Sept, 04:0014,126 MW14,425 MW
19 Sept, 05:0014,354 MW14,650 MW
19 Sept, 06:0014,910 MW15,425 MW
19 Sept, 07:0015,811 MW16,513 MW
19 Sept, 08:0016,768 MW17,500 MW
19 Sept, 09:0017,198 MW17,950 MW
19 Sept, 10:0017,238 MW17,825 MW
19 Sept, 11:0017,548 MW17,563 MW
19 Sept, 12:0017,526 MW17,550 MW
19 Sept, 13:0017,308 MW17,550 MW
19 Sept, 14:0017,007 MW17,550 MW
19 Sept, 15:0017,154 MW17,550 MW
19 Sept, 16:0016,889 MW17,675 MW
19 Sept, 17:0017,445 MW17,750 MW
19 Sept, 18:0017,351 MW17,913 MW
19 Sept, 19:0017,890 MW18,413 MW
19 Sept, 20:0017,435 MW18,075 MW
19 Sept, 21:0016,341 MW16,700 MW
19 Sept, 22:0015,110 MW15,538 MW
19 Sept, 23:0014,020 MW14,288 MW
20 Sept, 00:0013,464 MW13,000 MW
20 Sept, 01:0012,966 MW12,450 MW
20 Sept, 02:0012,487 MW12,138 MW
20 Sept, 03:0012,332 MW12,050 MW
20 Sept, 04:0012,324 MW12,050 MW
20 Sept, 05:0012,565 MW12,088 MW
20 Sept, 06:0012,798 MW12,450 MW
20 Sept, 07:0013,326 MW13,250 MW
20 Sept, 08:0013,993 MW14,238 MW
20 Sept, 09:0014,987 MW15,063 MW
20 Sept, 10:0015,321 MW15,550 MW
20 Sept, 11:0015,989 MW15,788 MW
20 Sept, 12:0015,964 MW15,825 MW
20 Sept, 13:0015,703 MW15,913 MW

Assumptions

  • Only hours with both a forecast and a positive demand reading count (686 of 686 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.