Organizations: State Key Laboratory of Cognitive Intelligence, University of Science and Technology of China, Hefei, China · Shenzhen International Graduate School, Tsinghua University, Shenzhen, China
Accurate electricity load forecasting provides critical decision support for energy procurement, generation scheduling, and supply-demand balancing, contributing to the economic efficiency and operational reliability of power systems. However, future electricity demand can be affected by the complex interplay of multiple events described in Web notices, weather alerts, and event schedules. Their effects vary over time and can reinforce or offset one another, making electricity load difficult to forecast accurately. While existing methods can incorporate context as additional input, how to use the effects of multiple events and their interactions to guide the load forecasting process itself remains to be explored. To address this gap, we propose ElecLoad, a context-aware agent for multi-event electricity load forecasting that adaptively organizes the forecasting process. Specifically, we train ElecLoad to combine historical load with context to analyze each event's relevance to the target load, the timing of its effects, and potential interactions among events. Guided by this analysis, ElecLoad adaptively chooses to forecast the entire forecast horizon directly or to partition it into segments according to changes in event effects. When the horizon is partitioned, sub-agents independently generate initial forecasts for each segment. The main agent then reviews these forecasts, and the sub-agents perform selective refinement guided by its feedback. Experiments on multiple electricity load datasets show that ElecLoad achieves state-of-the-art performance in most evaluation scenarios. Code is available at https://github.com/zhjai/ElecLoad.
Figures & tables
Figure 1. Conceptual illustration of (a) load changes under multiple events over time and (b) event-guided forecast partitioning in ElecLoad.
Figure 2. ElecLoad uses multi-event analysis to adaptively choose direct or segmented forecasting. In the segmented path, the main agent selects segments for feedback and refinement. The main agent and sub-agents share the same LLM weights. Historical load and context enter ElecLoad. Event analysis guides the choice between direct forecasting of the full horizon and partitioning into segments. On the segmented path, sub-agents generate forecasts. The main agent provides feedback on selected segments; their sub-agents refine the forecasts and return them for reassessment. After stopping, segment forecasts are assembled in time order, with optional adjustments near segment boundaries. Both paths produce a final load forecast.
Source
L/H
Train
Val.
ID test
OOD test
Total
GEFCom2014
96/96
640
100
200
0
940
Nord
168/24
288
48
96
0
432
96/96
72
12
24
0
108
PJM
168/24
320
56
112
0
488
96/96
80
14
28
0
122
SPP
168/24
160
24
48
0
232
Table 1. Dataset sizes by forecasting window. L/H : history/forecast hours. ERCOT includes 71 system-level cases for the main evaluation and 14 regional sensitivity cases.
Multi-day forecasting ( L=96,H=96 )
Day-ahead forecasting ( L=168,H=24 )
Method
GEFCom2014
Nord
PJM
SPP
AEMO †
Nord
PJM
SPP
LCL
iFlex
ERCOT †
WAPE
NRMSE
WAPE
NRMSE
WAPE
NRMSE
WAPE
NRMSE
WAPE
NRMSE
WAPE
NRMSE
WAPE
NRMSE
WAPE
NRMSE
WAPE
NRMSE
WAPE
NRMSE
WAPE
NRMSE
ARIMAX
17.63
20.91
7.49
8.87
10.09
11.62
6.09
7.08
29.21
33.83
5.48
6.58
7.01
8.07
6.25
7.11
808.45
964.88
30.19
37.34
7.44
8.86
LightGBM
9.03
10.90
5.93
6.90
7.07
8.15
4.50
5.51
15.57
20.06
4.84
5.56
4.89
5.75
4.76
5.64
1008.97
1167.11
34.94
41.98
7.55
8.51
PatchTST
13.82
16.91
7.97
9.35
7.52
8.96
5.07
6.23
18.45
22.67
5.22
6.14
5.08
6.28
4.33
5.46
1873.00
2151.25
31.19
39.03
7.00
8.56
TimeXer
13.40
16.45
8.18
9.58
7.84
9.21
4.92
5.96
15.85
20.11
4.96
5.69
4.71
5.74
4.16
5.01
958.83
1120.30
30.49
38.58
7.18
8.47
Table 2. Overall performance in multi-day and day-ahead load forecasting. WAPE and NRMSE are reported as percentages. Best results are bold; second-best results are underlined. L/H : history length/forecast horizon in hours.
Figure 3. Forecasting on GEFCom2014 synthetic event cases. (a) WAPE for four event conditions; 0 retains the original target without added events. (b) IEE grouped by zero/nonzero target interaction. (c,d) WAPE and IEE across generalization settings.
Group
Variant
GEFCom2014
PJM
LCL
WAPE
NRMSE
WAPE
NRMSE
WAPE
NRMSE
Reference
ElecLoad (Full)
6.68
8.42
3.13
3.86
41.94
77.24
Inputs
w/o event text
8.46
10.63
3.51
4.37
46.27
83.16
w/o covariates
7.39
9.36
3.79
4.71
44.12
80.58
Planning
w/ direct only
7.82
9.91
3.48
4.32
42.91
78.83
w/ segmented only
6.97
8.86
3.39
4.21
45.36
82.07
Table 3. Ablation study ( L=96 , H=96 for GEFCom2014; L=168 , H=24 for PJM and LCL).
Figure 4. WAPE versus normalized token cost on GEFCom2014: (a) routing; (b) refinement and reconciliation. Two square scatter plots show WAPE (%) vertically against normalized token cost horizontally for GEFCom2014 policies. Adaptive routing compares direct-only, segmented-only, and ElecLoad (Full). Segmented only compares segmented-only, no refinement, random refinement, no reconciliation, and forced reconciliation on the same cases under forced segmented forecasting. Points are unconnected, and segmented-only has identical coordinates in both panels.
Figure 5. ElecLoad case: (a) T1 planning and T2 initial forecasts; (b) T3-guided refinement and T4 boundary reconciliation. Two panels show a 96-step electricity load forecast, with forecast step on the horizontal axes and load in arbitrary units on the vertical axes. Panel a shows a heatwave from steps 24 to 65 and demand response from steps 36 to 60 above three event-guided segments, S1, S2, and S3. The lower plot compares Ground truth with Initial prediction, which is too high within S2. Panel b compares Ground truth, Initial, After T3, and Final. Purple shading identifies S2 for refinement, and green bands with T4 arrows identify reconciliation near its boundaries. The summary reports WAPE values of 4.17%, 2.07%, and 1.91% and cumulative costs of 19.5k, 25.9k, and 26.2k tokens for Initial, After T3, and Final, respectively.
Group
Variant
GEFCom2014
PJM
LCL
E
C
G
E
C
G
E
C
G
Routing
w/ direct only
7.82
7.8
—
3.48
7.0
—
42.91
6.5
—
w/ segmented only
6.97
24.0
0.052
3.39
22.0
0.006
45.36
20.0
-0.181
ElecLoad (Full)
6.68
18.7
0.105
3.13
15.3
0.042
41.94
12.7
0.156
Refinement
w/o refinement
7.24
15.0
—
3.37
12.2
—
44.63
10.0
—
w/ random refinement
6.94
18.6
0.083
3.32
15.2
0.017
43.06
12.8
0.561
Table 5. Ablations of routing, refinement, and reconciliation.
Appendix figures & tables11 assets
Supplementary material from the paper’s appendix.
Appendix
Source
Split
Date range
GEFCom2014
Train
2005-01-05–2009-10-31
Val.
2009-11-08–2010-11-11
Test
2010-11-19–2011-11-26
Nord
Train
2015-06-30–2022-12-30
Val.
2023-01-01–2023-12-05
Test
2024-01-01–2024-11-19
Appendix
Table 6. Calendar date ranges by data source and split.
Split
N
0
H
I
1
≥ 2
Overlap
Train
640
105
15
80
250
190
130 (68.4)
Val.
100
15
2
20
36
27
20 (74.1)
ID test
200
30
4
40
72
54
40 (74.1)
Appendix
Table 7. GEFCom2014 case composition ( L=96 , H=96 ).
Event descriptions
Source
L/H
N
0
1
2
≥ 3
Overlap
Incomp.
ID test
GEFCom2014 original
96/96
30
30
0
0
0
0
0
GEFCom2014 synthetic
96/96
170
0
102
58
10
40 (23.5%)
0
Nord
168/24
96
0
54
30
12
30 (31.2%)
16
Nord
96/96
24
0
15
5
4
3 (12.5%)
11
Appendix
Table 8. Test-set event descriptions and temporal overlap.
Dataset
Event Condition
N
Full
Direct
No text
Δ
GEFCom2014
Single Event
72
6.42
7.90
8.20
-1.48
Multiple Events
54
7.61
9.50
10.80
-1.89
PJM
No Event
35
2.63
2.80
2.41
-0.17
Single Event
45
3.12
3.42
3.57
-0.30
Multiple Events
32
3.69
4.31
4.63
-0.62
SPP
Single Event
18
2.74
2.91
3.08
-0.17
Appendix
Table 9. WAPE by number of events ( L=96 , H=96 for GEFCom2014; L=168 , H=24 for PJM and SPP).
Setting
Value
Agent RL batch; epochs; learning rate
16;2;10−6
Train/validation; PPO clip; KL
1800/300;0.2;0.001
Prompt/response/context tokens
32768/4096/36864
Train/validation temperature
1/0
Max segments; minimum steps
4;6
Refinements; repairs/call
2;1
Appendix
Table 10. Runtime settings.
Setting
GEFCom2014
PJM
LCL
ElecLoad 0.8B
8.14
3.37
47.36
ElecLoad 4B
6.68
3.13
41.94
ElecLoad 9B
6.63
3.16
41.81
w/o Reasoning init.
7.42
3.46
45.08
w/o Agent training
8.05
3.83
47.18
w/o Agent SFT
7.19
3.42
44.28
Appendix
Table 11. Model scale and training.
Group
Removed component
GEFCom2014
PJM
LCL
kTok
Reasoning
Numerical term
8.13
3.83
48.01
–
Improvement bonus
7.52
3.53
44.97
–
Scale penalty
7.62
3.66
47.27
–
Extreme penalty
7.56
3.52
46.87
–
Format penalty
7.45
3.52
45.03
–
Agent
Final accuracy credit
7.48
3.58
45.72
17.7
Appendix
Table 12. Training-component ablations.
Setting
GEFCom2014
PJM
LCL
kTok
Default
6.68
3.13
41.94
18.7
At most 2 segments
6.95
3.26
42.05
15.9
At most 3 segments
6.73
3.14
41.98
17.5
Force 4 segments
7.06
3.33
44.93
26.1
Refine first segment
6.98
3.35
43.46
18.5
Force 1 refinement
6.85
3.21
42.73
17.3
Appendix
Table 13. Execution variants.
Figure 6. Mean WAPE change after adding irrelevant text on GEFCom2014 (pp: percentage points).