DOPD Demand Forecast Accuracy: Error, Bias and Worst Miss, 21 August to 20 September 2026
The day-ahead demand forecast for DOPD was off by 3.4% on average (mean absolute percentage error) over 695 hours from 21 August to 20 September 2026, and 76% of hours landed within 5% of the reading. Its bias was +2.2%: it ran high on average, an over forecast. The largest miss was 34 MW (15.7%) too high at 5 Sept 2026, 05:00 PDT (UTC-07:00). Dates and times are local (America/Los_Angeles).
Key Facts
- The day-ahead demand forecast for DOPD was off by 3.4% on average (mean absolute percentage error) over 695 hours from 21 August to 20 September 2026, and 76% of hours landed within 5% of the reading. Its bias was +2.2%: it ran high on average, an over forecast. The largest miss was 34 MW (15.7%) too high at 5 Sept 2026, 05:00 PDT (UTC-07:00).
- Across 53 US grids ranked by average error over their own latest 30 day windows, DOPD came 22 (1 is the smallest error).
- On average the forecast differed from reported demand by 9 MW, against average demand of 263 MW.
- The forecast was above reported demand in 69% of compared hours.
Forecast Error at a Glance
695 hours from 21 August to 20 September 2026Average error3.4%
Bias+2.2%
Hours within 5%76%
Worst miss34 MW
Average error is the mean absolute percentage gap between the forecast and reported demand. Bias is the signed mean (+5 MW per hour on average): the forecast ran high on average, an over forecast. The worst miss was 34 MW (15.7%) too high at 5 Sept 2026, 05:00 PDT (UTC-07:00): forecast 251 MW, reported 217 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, 18:00 PDT (UTC-07:00)Data to 2026-09-20
| Local hour | Reported demand | Day-ahead forecast |
|---|---|---|
| 13 Sept, 19:00 | 248 MW | 253 MW |
| 13 Sept, 20:00 | 244 MW | 249 MW |
| 13 Sept, 21:00 | 237 MW | 245 MW |
| 13 Sept, 22:00 | 228 MW | 239 MW |
| 13 Sept, 23:00 | 222 MW | 233 MW |
| 14 Sept, 00:00 | 216 MW | 229 MW |
| 14 Sept, 01:00 | 213 MW | 225 MW |
| 14 Sept, 02:00 | 212 MW | 223 MW |
| 14 Sept, 03:00 | 215 MW | 223 MW |
| 14 Sept, 04:00 | 218 MW | 229 MW |
| 14 Sept, 05:00 | 234 MW | 239 MW |
| 14 Sept, 06:00 | 253 MW | 250 MW |
| 14 Sept, 07:00 | 262 MW | 259 MW |
| 14 Sept, 08:00 | 263 MW | 264 MW |
| 14 Sept, 09:00 | 255 MW | 265 MW |
| 14 Sept, 10:00 | 251 MW | 265 MW |
| 14 Sept, 11:00 | 249 MW | 266 MW |
| 14 Sept, 12:00 | 252 MW | 268 MW |
| 14 Sept, 13:00 | 246 MW | 271 MW |
| 14 Sept, 14:00 | 250 MW | 274 MW |
| 14 Sept, 15:00 | 253 MW | 277 MW |
| 14 Sept, 16:00 | 252 MW | 279 MW |
| 14 Sept, 17:00 | 261 MW | 279 MW |
| 14 Sept, 18:00 | 258 MW | 277 MW |
| 14 Sept, 19:00 | 258 MW | 274 MW |
| 14 Sept, 20:00 | 252 MW | 269 MW |
| 14 Sept, 21:00 | 241 MW | 261 MW |
| 14 Sept, 22:00 | 232 MW | 252 MW |
| 14 Sept, 23:00 | 220 MW | 242 MW |
| 15 Sept, 00:00 | 215 MW | 236 MW |
| 15 Sept, 01:00 | 214 MW | 231 MW |
| 15 Sept, 02:00 | 205 MW | 229 MW |
| 15 Sept, 03:00 | 210 MW | 229 MW |
| 15 Sept, 04:00 | 213 MW | 233 MW |
| 15 Sept, 05:00 | 229 MW | 240 MW |
| 15 Sept, 06:00 | 239 MW | 249 MW |
| 15 Sept, 07:00 | 248 MW | 258 MW |
| 15 Sept, 08:00 | 246 MW | 263 MW |
| 15 Sept, 09:00 | 253 MW | 263 MW |
| 15 Sept, 10:00 | 252 MW | 261 MW |
| 15 Sept, 11:00 | 249 MW | 259 MW |
| 15 Sept, 12:00 | 250 MW | 257 MW |
| 15 Sept, 13:00 | 246 MW | 257 MW |
| 15 Sept, 14:00 | 249 MW | 259 MW |
| 15 Sept, 15:00 | 252 MW | 262 MW |
| 15 Sept, 16:00 | 251 MW | 265 MW |
| 15 Sept, 17:00 | 251 MW | 266 MW |
| 15 Sept, 18:00 | 253 MW | 264 MW |
| 15 Sept, 19:00 | 255 MW | 261 MW |
| 15 Sept, 20:00 | 250 MW | 257 MW |
| 15 Sept, 21:00 | 241 MW | 252 MW |
| 15 Sept, 22:00 | 231 MW | 246 MW |
| 15 Sept, 23:00 | 220 MW | 240 MW |
| 16 Sept, 00:00 | 215 MW | 233 MW |
| 16 Sept, 01:00 | 210 MW | 229 MW |
| 16 Sept, 02:00 | 211 MW | 227 MW |
| 16 Sept, 03:00 | 211 MW | 228 MW |
| 16 Sept, 04:00 | 215 MW | 233 MW |
| 16 Sept, 05:00 | 231 MW | 244 MW |
| 16 Sept, 06:00 | 246 MW | 258 MW |
| 16 Sept, 07:00 | 251 MW | 268 MW |
| 16 Sept, 08:00 | 246 MW | 270 MW |
| 16 Sept, 09:00 | 249 MW | 266 MW |
| 16 Sept, 10:00 | 248 MW | 264 MW |
| 16 Sept, 11:00 | 250 MW | 265 MW |
| 16 Sept, 12:00 | 250 MW | 267 MW |
| 16 Sept, 13:00 | 252 MW | 270 MW |
| 16 Sept, 14:00 | 256 MW | 273 MW |
| 16 Sept, 15:00 | 261 MW | 276 MW |
| 16 Sept, 16:00 | 261 MW | 278 MW |
| 16 Sept, 17:00 | 271 MW | 278 MW |
| 16 Sept, 18:00 | 270 MW | 276 MW |
| 16 Sept, 19:00 | 263 MW | 272 MW |
| 16 Sept, 20:00 | 257 MW | 267 MW |
| 16 Sept, 21:00 | 247 MW | 260 MW |
| 16 Sept, 22:00 | 234 MW | 250 MW |
| 16 Sept, 23:00 | 221 MW | 239 MW |
| 17 Sept, 00:00 | 211 MW | 229 MW |
| 17 Sept, 01:00 | 212 MW | 224 MW |
| 17 Sept, 02:00 | 210 MW | 222 MW |
| 17 Sept, 03:00 | 210 MW | 223 MW |
| 17 Sept, 04:00 | 218 MW | 229 MW |
| 17 Sept, 05:00 | 230 MW | 240 MW |
| 17 Sept, 06:00 | 246 MW | 252 MW |
| 17 Sept, 07:00 | 254 MW | 262 MW |
| 17 Sept, 08:00 | 255 MW | 267 MW |
| 17 Sept, 09:00 | 251 MW | 269 MW |
| 17 Sept, 10:00 | 255 MW | 271 MW |
| 17 Sept, 11:00 | 253 MW | 273 MW |
| 17 Sept, 12:00 | 260 MW | 277 MW |
| 17 Sept, 13:00 | 261 MW | 282 MW |
| 17 Sept, 14:00 | 270 MW | 288 MW |
| 17 Sept, 15:00 | 278 MW | 293 MW |
| 17 Sept, 16:00 | 282 MW | 296 MW |
| 17 Sept, 17:00 | 284 MW | 297 MW |
| 17 Sept, 18:00 | 280 MW | 295 MW |
| 17 Sept, 19:00 | 279 MW | 290 MW |
| 17 Sept, 20:00 | 265 MW | 283 MW |
| 17 Sept, 21:00 | 252 MW | 273 MW |
| 17 Sept, 22:00 | 242 MW | 259 MW |
| 17 Sept, 23:00 | 231 MW | 243 MW |
| 18 Sept, 00:00 | 226 MW | 231 MW |
| 18 Sept, 01:00 | 220 MW | 225 MW |
| 18 Sept, 02:00 | 218 MW | 222 MW |
| 18 Sept, 03:00 | 220 MW | 223 MW |
| 18 Sept, 04:00 | 221 MW | 229 MW |
| 18 Sept, 05:00 | 236 MW | 238 MW |
| 18 Sept, 06:00 | 251 MW | 250 MW |
| 18 Sept, 07:00 | 255 MW | 260 MW |
| 18 Sept, 08:00 | 254 MW | 264 MW |
| 18 Sept, 09:00 | 252 MW | 262 MW |
| 18 Sept, 10:00 | 255 MW | 261 MW |
| 18 Sept, 11:00 | 259 MW | 261 MW |
| 18 Sept, 12:00 | 262 MW | 262 MW |
| 18 Sept, 13:00 | 269 MW | 264 MW |
| 18 Sept, 14:00 | 278 MW | 267 MW |
| 18 Sept, 15:00 | 278 MW | 271 MW |
| 18 Sept, 16:00 | 285 MW | 275 MW |
| 18 Sept, 17:00 | 293 MW | 277 MW |
| 18 Sept, 18:00 | 283 MW | 275 MW |
| 18 Sept, 19:00 | 273 MW | 270 MW |
| 18 Sept, 20:00 | 264 MW | 263 MW |
| 18 Sept, 21:00 | 260 MW | 253 MW |
| 18 Sept, 22:00 | 246 MW | 243 MW |
| 18 Sept, 23:00 | 236 MW | 231 MW |
| 19 Sept, 00:00 | 223 MW | 227 MW |
| 19 Sept, 01:00 | 224 MW | 223 MW |
| 19 Sept, 02:00 | 222 MW | 221 MW |
| 19 Sept, 03:00 | 219 MW | 222 MW |
| 19 Sept, 04:00 | 222 MW | 227 MW |
| 19 Sept, 05:00 | 227 MW | 234 MW |
| 19 Sept, 06:00 | 232 MW | 242 MW |
| 19 Sept, 07:00 | 243 MW | 249 MW |
| 19 Sept, 08:00 | 246 MW | 254 MW |
| 19 Sept, 09:00 | 248 MW | 257 MW |
| 19 Sept, 10:00 | 252 MW | 261 MW |
| 19 Sept, 11:00 | 252 MW | 264 MW |
| 19 Sept, 12:00 | 259 MW | 267 MW |
| 19 Sept, 13:00 | 267 MW | 270 MW |
| 19 Sept, 14:00 | 272 MW | 273 MW |
| 19 Sept, 15:00 | 280 MW | 275 MW |
| 19 Sept, 16:00 | 287 MW | 277 MW |
| 19 Sept, 17:00 | 287 MW | 277 MW |
| 19 Sept, 18:00 | 278 MW | 275 MW |
| 19 Sept, 19:00 | 270 MW | 270 MW |
| 19 Sept, 20:00 | 265 MW | 263 MW |
| 19 Sept, 21:00 | 248 MW | 254 MW |
| 19 Sept, 22:00 | 243 MW | 244 MW |
| 19 Sept, 23:00 | 233 MW | 232 MW |
| 20 Sept, 00:00 | 229 MW | 228 MW |
| 20 Sept, 01:00 | 220 MW | 225 MW |
| 20 Sept, 02:00 | 222 MW | 223 MW |
| 20 Sept, 03:00 | 218 MW | 224 MW |
| 20 Sept, 04:00 | 218 MW | 228 MW |
| 20 Sept, 05:00 | 224 MW | 236 MW |
| 20 Sept, 06:00 | 227 MW | 244 MW |
| 20 Sept, 07:00 | 237 MW | 250 MW |
| 20 Sept, 08:00 | 242 MW | 254 MW |
| 20 Sept, 09:00 | 249 MW | 257 MW |
| 20 Sept, 10:00 | 253 MW | 260 MW |
| 20 Sept, 11:00 | 260 MW | 264 MW |
| 20 Sept, 12:00 | 267 MW | 268 MW |
| 20 Sept, 13:00 | 271 MW | 272 MW |
| 20 Sept, 14:00 | 278 MW | 277 MW |
| 20 Sept, 15:00 | 286 MW | 283 MW |
| 20 Sept, 16:00 | 288 MW | 288 MW |
| 20 Sept, 17:00 | 294 MW | 290 MW |
| 20 Sept, 18:00 | 288 MW | 288 MW |
Assumptions
- Only hours with both a forecast and a positive demand reading count (695 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.