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

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

The day-ahead demand forecast for FPL was off by 2.9% on average (mean absolute percentage error) over 718 hours from 21 August to 20 September 2026, and 82% of hours landed within 5% of the reading. Its bias was -0.0%: it ran close to balanced on average. The largest miss was 2,932 MW (14.3%) too high at 29 Aug 2026, 17:00 EDT (UTC-04:00). Dates and times are local (America/New_York).

Key Facts

  • The day-ahead demand forecast for FPL was off by 2.9% on average (mean absolute percentage error) over 718 hours from 21 August to 20 September 2026, and 82% of hours landed within 5% of the reading. Its bias was -0.0%: it ran close to balanced on average. The largest miss was 2,932 MW (14.3%) too high at 29 Aug 2026, 17:00 EDT (UTC-04:00).
  • Across 53 US grids ranked by average error over their own latest 30 day windows, FPL came 16 (1 is the smallest error).
  • On average the forecast differed from reported demand by 601 MW, against average demand of 19,768 MW.
  • The forecast was above reported demand in 48% of compared hours.

Forecast Error at a Glance

718 hours from 21 August to 20 September 2026
Average error2.9%
Bias-0.0%
Hours within 5%82%
Worst miss2,932 MW

Average error is the mean absolute percentage gap between the forecast and reported demand. Bias is the signed mean (-7 MW per hour on average): the forecast ran close to balanced on average. The worst miss was 2,932 MW (14.3%) too high at 29 Aug 2026, 17:00 EDT (UTC-04:00): forecast 23,497 MW, reported 20,565 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)
FPL day-ahead demand forecast and reported demand by hour Hourly reported demand and the day-ahead forecast for FPL 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 7,500 15,000 22,500 30,000 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 FPL 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
FPL day-ahead demand forecast and reported demand by hour
Local hourReported demandDay-ahead forecast
13 Sept, 22:0018,793 MW18,317 MW
13 Sept, 23:0017,285 MW16,875 MW
14 Sept, 00:0015,940 MW15,515 MW
14 Sept, 01:0014,960 MW14,828 MW
14 Sept, 02:0014,516 MW14,045 MW
14 Sept, 03:0014,267 MW13,838 MW
14 Sept, 04:0013,886 MW13,929 MW
14 Sept, 05:0014,255 MW14,471 MW
14 Sept, 06:0014,800 MW15,199 MW
14 Sept, 07:0015,417 MW16,001 MW
14 Sept, 08:0016,822 MW17,347 MW
14 Sept, 09:0019,331 MW19,386 MW
14 Sept, 10:0021,027 MW21,039 MW
14 Sept, 11:0022,711 MW22,518 MW
14 Sept, 12:0024,414 MW23,976 MW
14 Sept, 13:0025,585 MW24,860 MW
14 Sept, 14:0026,308 MW24,897 MW
14 Sept, 15:0026,712 MW24,770 MW
14 Sept, 16:0026,865 MW24,301 MW
14 Sept, 17:0026,644 MW24,013 MW
14 Sept, 18:0025,286 MW23,232 MW
14 Sept, 19:0023,921 MW22,808 MW
14 Sept, 20:0023,676 MW21,977 MW
14 Sept, 21:0022,948 MW20,703 MW
14 Sept, 22:0021,174 MW19,260 MW
14 Sept, 23:0019,461 MW17,748 MW
15 Sept, 00:0017,973 MW17,073 MW
15 Sept, 01:0017,062 MW16,539 MW
15 Sept, 02:0016,249 MW15,644 MW
15 Sept, 03:0015,663 MW15,389 MW
15 Sept, 04:0015,432 MW15,271 MW
15 Sept, 05:0015,751 MW15,919 MW
15 Sept, 06:0016,486 MW16,407 MW
15 Sept, 07:0016,743 MW16,895 MW
15 Sept, 08:0018,109 MW18,525 MW
15 Sept, 09:0020,289 MW20,234 MW
15 Sept, 10:0022,290 MW21,892 MW
15 Sept, 11:0023,635 MW23,368 MW
15 Sept, 12:0024,967 MW24,760 MW
15 Sept, 13:0026,083 MW25,509 MW
15 Sept, 14:0026,600 MW25,769 MW
15 Sept, 15:0026,836 MW25,490 MW
15 Sept, 16:0026,684 MW25,135 MW
15 Sept, 17:0025,930 MW24,703 MW
15 Sept, 18:0024,924 MW23,803 MW
15 Sept, 19:0024,054 MW23,215 MW
15 Sept, 20:0023,544 MW22,319 MW
15 Sept, 21:0022,929 MW20,899 MW
15 Sept, 22:0021,756 MW19,478 MW
15 Sept, 23:0020,054 MW17,892 MW
16 Sept, 00:0018,520 MW17,588 MW
16 Sept, 01:0017,341 MW16,645 MW
16 Sept, 02:0016,526 MW15,916 MW
16 Sept, 03:0016,062 MW15,692 MW
16 Sept, 04:0015,969 MW15,552 MW
16 Sept, 05:0016,216 MW16,333 MW
16 Sept, 06:0016,856 MW17,063 MW
16 Sept, 07:0017,104 MW17,299 MW
16 Sept, 08:0018,080 MW18,627 MW
16 Sept, 09:0019,664 MW20,002 MW
16 Sept, 10:0021,510 MW21,560 MW
16 Sept, 11:0022,848 MW22,690 MW
16 Sept, 12:0023,827 MW23,905 MW
16 Sept, 13:0024,386 MW24,639 MW
16 Sept, 14:0025,212 MW24,673 MW
16 Sept, 15:0025,741 MW24,651 MW
16 Sept, 16:0025,578 MW24,294 MW
16 Sept, 17:0024,904 MW23,966 MW
16 Sept, 18:0023,690 MW23,158 MW
16 Sept, 19:0022,827 MW22,700 MW
16 Sept, 20:0022,502 MW21,719 MW
16 Sept, 21:0021,816 MW20,477 MW
16 Sept, 22:0020,168 MW18,990 MW
16 Sept, 23:0018,560 MW17,413 MW
17 Sept, 00:0017,192 MW16,566 MW
17 Sept, 01:0016,167 MW15,654 MW
17 Sept, 02:0015,361 MW15,138 MW
17 Sept, 03:0014,833 MW14,511 MW
17 Sept, 04:0014,662 MW14,573 MW
17 Sept, 05:0015,090 MW15,256 MW
17 Sept, 06:0015,879 MW15,924 MW
17 Sept, 07:0016,171 MW16,174 MW
17 Sept, 08:0017,333 MW17,733 MW
17 Sept, 09:0018,758 MW18,894 MW
17 Sept, 10:0019,952 MW20,202 MW
17 Sept, 11:0020,706 MW21,295 MW
17 Sept, 12:0020,735 MW22,334 MW
17 Sept, 13:0020,995 MW23,424 MW
17 Sept, 14:0021,629 MW23,834 MW
17 Sept, 15:0022,418 MW23,966 MW
17 Sept, 16:0023,161 MW23,945 MW
17 Sept, 17:0023,384 MW23,740 MW
17 Sept, 18:0022,226 MW22,589 MW
17 Sept, 19:0021,140 MW22,178 MW
17 Sept, 20:0020,862 MW21,084 MW
17 Sept, 21:0020,096 MW19,797 MW
17 Sept, 22:0018,911 MW18,390 MW
17 Sept, 23:0017,488 MW16,948 MW
18 Sept, 00:0016,171 MW15,763 MW
18 Sept, 01:0015,110 MW14,629 MW
18 Sept, 02:0014,409 MW14,016 MW
18 Sept, 03:0014,033 MW13,707 MW
18 Sept, 04:0013,823 MW13,650 MW
18 Sept, 05:0014,277 MW14,266 MW
18 Sept, 06:0015,031 MW15,061 MW
18 Sept, 07:0015,283 MW15,397 MW
18 Sept, 08:0016,900 MW16,784 MW
18 Sept, 09:0019,072 MW18,487 MW
18 Sept, 10:0020,598 MW19,599 MW
18 Sept, 11:0021,765 MW20,787 MW
18 Sept, 12:0022,322 MW21,659 MW
18 Sept, 13:0023,233 MW22,583 MW
18 Sept, 14:0023,115 MW22,934 MW
18 Sept, 15:0022,423 MW23,156 MW
18 Sept, 16:0021,898 MW23,068 MW
18 Sept, 17:0021,148 MW22,518 MW
18 Sept, 18:0020,133 MW21,278 MW
18 Sept, 19:0019,463 MW20,717 MW
18 Sept, 20:0018,975 MW19,799 MW
18 Sept, 21:0017,716 MW18,726 MW
18 Sept, 22:0017,109 MW17,555 MW
18 Sept, 23:0016,262 MW16,420 MW
19 Sept, 00:0015,219 MW14,866 MW
19 Sept, 01:0014,265 MW13,709 MW
19 Sept, 02:0013,527 MW13,201 MW
19 Sept, 03:0013,058 MW12,744 MW
19 Sept, 04:0012,828 MW12,748 MW
19 Sept, 05:0012,869 MW12,886 MW
19 Sept, 06:0013,131 MW13,106 MW
19 Sept, 07:0013,505 MW13,477 MW
19 Sept, 08:0015,061 MW15,234 MW
19 Sept, 09:0017,116 MW17,058 MW
19 Sept, 10:0018,425 MW18,747 MW
19 Sept, 11:0020,027 MW20,077 MW
19 Sept, 12:0021,631 MW20,994 MW
19 Sept, 13:0022,798 MW21,603 MW
19 Sept, 14:0023,586 MW21,566 MW
19 Sept, 15:0023,809 MW21,641 MW
19 Sept, 16:0023,410 MW21,633 MW
19 Sept, 17:0022,535 MW21,167 MW
19 Sept, 18:0021,072 MW20,216 MW
19 Sept, 19:0019,959 MW19,709 MW
19 Sept, 20:0019,664 MW18,984 MW
19 Sept, 21:0018,913 MW18,080 MW
19 Sept, 22:0017,749 MW17,101 MW
19 Sept, 23:0016,520 MW15,989 MW
20 Sept, 00:0014,916 MW14,786 MW
20 Sept, 01:0013,964 MW13,903 MW
20 Sept, 02:0013,276 MW13,341 MW
20 Sept, 03:0012,743 MW12,828 MW
20 Sept, 04:0012,571 MW12,608 MW
20 Sept, 05:0012,619 MW12,751 MW
20 Sept, 06:0012,619 MW12,874 MW
20 Sept, 07:0012,811 MW13,352 MW
20 Sept, 08:0014,093 MW15,230 MW
20 Sept, 09:0015,685 MW16,826 MW
20 Sept, 10:0017,127 MW18,566 MW
20 Sept, 11:0018,915 MW20,008 MW
20 Sept, 12:0020,570 MW21,163 MW
20 Sept, 13:0021,555 MW21,751 MW
20 Sept, 14:0021,578 MW21,932 MW
20 Sept, 15:0020,963 MW21,567 MW
20 Sept, 16:0020,600 MW21,496 MW
20 Sept, 17:0020,338 MW20,845 MW
20 Sept, 18:0019,873 MW20,103 MW
20 Sept, 19:0019,373 MW19,755 MW
20 Sept, 20:0018,857 MW19,161 MW
20 Sept, 21:0017,852 MW18,025 MW

Assumptions

  • Only hours with both a forecast and a positive demand reading count (718 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.