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

DUK Demand Forecast Accuracy: Error, Bias and Worst Miss, 21 August to 20 September 2026

The day-ahead demand forecast for DUK was off by 2.8% on average (mean absolute percentage error) over 719 hours from 21 August to 20 September 2026, and 84% of hours landed within 5% of the reading. Its bias was +0.6%: it ran high on average, an over forecast. The largest miss was 3,613 MW (22.4%) too high at 5 Sept 2026, 17:00 EDT (UTC-04:00). Dates and times are local (America/New_York).

Key Facts

  • The day-ahead demand forecast for DUK was off by 2.8% on average (mean absolute percentage error) over 719 hours from 21 August to 20 September 2026, and 84% of hours landed within 5% of the reading. Its bias was +0.6%: it ran high on average, an over forecast. The largest miss was 3,613 MW (22.4%) too high at 5 Sept 2026, 17:00 EDT (UTC-04:00).
  • Across 53 US grids ranked by average error over their own latest 30 day windows, DUK came 15 (1 is the smallest error).
  • On average the forecast differed from reported demand by 405 MW, against average demand of 14,401 MW.
  • The forecast was above reported demand in 53% of compared hours.

Forecast Error at a Glance

719 hours from 21 August to 20 September 2026
Average error2.8%
Bias+0.6%
Hours within 5%84%
Worst miss3,613 MW

Average error is the mean absolute percentage gap between the forecast and reported demand. Bias is the signed mean (+90 MW per hour on average): the forecast ran high on average, an over forecast. The worst miss was 3,613 MW (22.4%) too high at 5 Sept 2026, 17:00 EDT (UTC-04:00): forecast 19,766 MW, reported 16,153 MW.

Source: U.S. Energy Information Administration (EIA). (US Government work, public domain) 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, 21:00 EDT (UTC-04:00)
DUK day-ahead demand forecast and reported demand by hour Hourly reported demand and the day-ahead forecast for DUK over the last 7 days of the window, to 20 Sept 2026, 21:00 EDT (UTC-04:00). Gaps are hours with a missing, zero or implausible report. 0 6,250 12,500 18,750 25,000 13 Sept, 22:0014 Sept, 22:0015 Sept, 22:0016 Sept, 22:0017 Sept, 22:0018 Sept, 22:0019 Sept, 22:00
Hourly reported demand and the day-ahead forecast for DUK over the last 7 days of the window, to 20 Sept 2026, 21:00 EDT (UTC-04:00). Gaps are hours with a missing, zero or implausible report.
Data to 2026-09-20
DUK day-ahead demand forecast and reported demand by hour
Local hourReported demandDay-ahead forecast
13 Sept, 22:0014,441 MW14,565 MW
13 Sept, 23:0013,203 MW13,405 MW
14 Sept, 00:0012,171 MW12,419 MW
14 Sept, 01:0011,431 MW11,645 MW
14 Sept, 02:0010,890 MW11,070 MW
14 Sept, 03:0010,562 MW10,758 MW
14 Sept, 04:0010,536 MW10,751 MW
14 Sept, 05:0010,940 MW11,226 MW
14 Sept, 06:0011,764 MW11,953 MW
14 Sept, 07:0012,152 MW12,554 MW
14 Sept, 08:0012,756 MW13,123 MW
14 Sept, 09:0013,683 MW13,941 MW
14 Sept, 10:0014,994 MW15,020 MW
14 Sept, 11:0016,390 MW16,269 MW
14 Sept, 12:0017,623 MW17,519 MW
14 Sept, 13:0018,671 MW18,567 MW
14 Sept, 14:0019,376 MW19,403 MW
14 Sept, 15:0019,860 MW19,992 MW
14 Sept, 16:0020,124 MW20,323 MW
14 Sept, 17:0020,020 MW20,180 MW
14 Sept, 18:0019,459 MW19,639 MW
14 Sept, 19:0018,539 MW18,799 MW
14 Sept, 20:0017,680 MW17,872 MW
14 Sept, 21:0016,416 MW16,609 MW
14 Sept, 22:0014,967 MW15,187 MW
14 Sept, 23:0013,639 MW13,840 MW
15 Sept, 00:0012,669 MW12,785 MW
15 Sept, 01:0011,814 MW11,950 MW
15 Sept, 02:0011,314 MW11,338 MW
15 Sept, 03:0011,005 MW10,974 MW
15 Sept, 04:0010,972 MW10,899 MW
15 Sept, 05:0011,386 MW11,298 MW
15 Sept, 06:0012,167 MW11,919 MW
15 Sept, 07:0012,558 MW12,356 MW
15 Sept, 08:0012,732 MW12,606 MW
15 Sept, 09:0013,009 MW12,976 MW
15 Sept, 10:0013,675 MW13,483 MW
15 Sept, 11:0014,048 MW14,152 MW
15 Sept, 12:0014,724 MW14,930 MW
15 Sept, 13:0015,377 MW15,719 MW
15 Sept, 14:0015,871 MW16,455 MW
15 Sept, 15:0016,411 MW17,095 MW
15 Sept, 16:0016,889 MW17,558 MW
15 Sept, 17:0017,031 MW17,608 MW
15 Sept, 18:0016,702 MW17,239 MW
15 Sept, 19:0016,126 MW16,564 MW
15 Sept, 20:0015,574 MW15,791 MW
15 Sept, 21:0014,580 MW14,706 MW
15 Sept, 22:0013,348 MW13,496 MW
15 Sept, 23:0012,161 MW12,333 MW
16 Sept, 00:0011,259 MW11,234 MW
16 Sept, 01:0010,656 MW10,568 MW
16 Sept, 02:0010,248 MW10,106 MW
16 Sept, 03:0010,009 MW9,865 MW
16 Sept, 04:0010,006 MW9,901 MW
16 Sept, 05:0010,440 MW10,387 MW
16 Sept, 06:0011,275 MW11,088 MW
16 Sept, 07:0011,677 MW11,591 MW
16 Sept, 08:0012,043 MW11,923 MW
16 Sept, 09:0012,513 MW12,422 MW
16 Sept, 10:0013,218 MW13,146 MW
16 Sept, 11:0014,117 MW14,015 MW
16 Sept, 12:0015,155 MW14,998 MW
16 Sept, 13:0016,220 MW15,991 MW
16 Sept, 14:0017,191 MW16,893 MW
16 Sept, 15:0017,978 MW17,621 MW
16 Sept, 16:0018,526 MW18,123 MW
16 Sept, 17:0018,602 MW18,176 MW
16 Sept, 18:0018,054 MW17,741 MW
16 Sept, 19:0017,116 MW16,971 MW
16 Sept, 20:0016,226 MW16,095 MW
16 Sept, 21:0015,170 MW14,958 MW
16 Sept, 22:0013,707 MW13,683 MW
16 Sept, 23:0012,128 MW12,474 MW
17 Sept, 00:0011,660 MW11,454 MW
17 Sept, 01:0010,740 MW10,740 MW
17 Sept, 02:0010,257 MW10,236 MW
17 Sept, 03:0010,002 MW9,984 MW
17 Sept, 04:009,982 MW10,003 MW
17 Sept, 05:0010,379 MW10,476 MW
17 Sept, 06:0011,168 MW11,172 MW
17 Sept, 07:0011,559 MW11,717 MW
17 Sept, 08:0012,011 MW12,148 MW
17 Sept, 09:0012,704 MW12,805 MW
17 Sept, 10:0013,633 MW13,726 MW
17 Sept, 11:0014,790 MW14,794 MW
17 Sept, 12:0016,038 MW15,949 MW
17 Sept, 13:0017,267 MW17,057 MW
17 Sept, 14:0018,193 MW18,010 MW
17 Sept, 15:0018,952 MW18,739 MW
17 Sept, 16:0019,440 MW19,225 MW
17 Sept, 17:0019,473 MW19,251 MW
17 Sept, 18:0018,851 MW18,785 MW
17 Sept, 19:0017,908 MW17,962 MW
17 Sept, 20:0017,090 MW17,024 MW
17 Sept, 21:0015,931 MW15,809 MW
17 Sept, 22:0014,661 MW14,449 MW
17 Sept, 23:0013,417 MW13,195 MW
18 Sept, 00:0012,459 MW12,240 MW
18 Sept, 01:0011,773 MW11,481 MW
18 Sept, 02:0011,302 MW10,926 MW
18 Sept, 03:0011,026 MW10,622 MW
18 Sept, 04:0011,006 MW10,604 MW
18 Sept, 05:0011,351 MW11,024 MW
18 Sept, 06:0012,066 MW11,689 MW
18 Sept, 07:0012,402 MW12,259 MW
18 Sept, 08:0012,952 MW12,844 MW
18 Sept, 09:0013,971 MW13,696 MW
18 Sept, 10:0015,471 MW14,799 MW
18 Sept, 11:0016,974 MW16,071 MW
18 Sept, 12:0018,425 MW17,335 MW
18 Sept, 13:0019,323 MW18,390 MW
18 Sept, 14:0019,333 MW19,125 MW
18 Sept, 15:0019,334 MW19,542 MW
18 Sept, 16:0018,886 MW19,687 MW
18 Sept, 17:0018,181 MW19,429 MW
18 Sept, 18:0017,395 MW18,788 MW
18 Sept, 19:0016,798 MW17,926 MW
18 Sept, 20:0016,104 MW17,072 MW
18 Sept, 21:0015,197 MW15,980 MW
18 Sept, 22:0014,208 MW14,751 MW
18 Sept, 23:0013,238 MW13,575 MW
19 Sept, 00:0012,288 MW12,847 MW
19 Sept, 01:0011,657 MW12,035 MW
19 Sept, 02:0011,164 MW11,406 MW
19 Sept, 03:0010,805 MW11,005 MW
19 Sept, 04:0010,625 MW10,783 MW
19 Sept, 05:0010,616 MW10,777 MW
19 Sept, 06:0010,795 MW10,889 MW
19 Sept, 07:0011,000 MW11,175 MW
19 Sept, 08:0011,706 MW11,775 MW
19 Sept, 09:0012,796 MW12,634 MW
19 Sept, 10:0013,542 MW13,521 MW
19 Sept, 11:0014,606 MW14,478 MW
19 Sept, 12:0015,623 MW15,360 MW
19 Sept, 13:0016,447 MW16,054 MW
19 Sept, 14:0017,129 MW16,478 MW
19 Sept, 15:0017,637 MW16,732 MW
19 Sept, 16:0017,798 MW16,785 MW
19 Sept, 17:0017,609 MW16,571 MW
19 Sept, 18:0016,926 MW16,023 MW
19 Sept, 19:0016,124 MW15,380 MW
19 Sept, 20:0015,430 MW14,726 MW
19 Sept, 21:0014,528 MW13,877 MW
19 Sept, 22:0013,599 MW12,887 MW
19 Sept, 23:0012,679 MW12,008 MW
20 Sept, 00:0011,845 MW11,667 MW
20 Sept, 01:0011,212 MW10,968 MW
20 Sept, 02:0010,621 MW10,432 MW
20 Sept, 03:0010,300 MW10,082 MW
20 Sept, 04:0010,100 MW9,900 MW
20 Sept, 05:0010,069 MW9,878 MW
20 Sept, 06:0010,131 MW9,993 MW
20 Sept, 07:0010,293 MW10,309 MW
20 Sept, 08:0011,003 MW10,964 MW
20 Sept, 09:0011,810 MW11,785 MW
20 Sept, 10:0012,665 MW12,676 MW
20 Sept, 11:0013,854 MW13,713 MW
20 Sept, 12:0015,024 MW14,845 MW
20 Sept, 13:0016,057 MW15,838 MW
20 Sept, 14:0016,914 MW16,585 MW
20 Sept, 15:0018,749 MW17,083 MW
20 Sept, 16:0017,829 MW17,408 MW
20 Sept, 17:0017,705 MW17,419 MW
20 Sept, 18:0017,030 MW17,091 MW
20 Sept, 19:0016,402 MW16,523 MW
20 Sept, 20:0017,003 MW15,855 MW
20 Sept, 21:0014,743 MW14,845 MW

Assumptions

  • Only hours with both a forecast and a positive demand reading count (719 of 720 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.
  • US figures are for the EIA balancing authority or region named on this page. US and European grids are ranked separately.