Executive Summary
The purpose of this report is to provide market participants a monthly summary of day-ahead and real-time markets performance for September, 2026. The key market performance highlights are presented here:
CAISO area performance:
Peak loads for the ISO area decreased in September compared to the previous month.
The cumulative frequency of prices in Fifteen-Minute Market (FMM) above $250/MWh decreased from 0.38 percent in August 2026 to 0.16 percent in September 2026, while the cumulative frequency of negative prices increased from 0.39 percent in August 2026 to 1.38 percent in September 2026. Average FMM Default Load Aggregation Point (DLAP) prices across PGAE, SCE, SDGE, and VEA decreased relative to the previous month.
The cumulative frequency of prices in Real-Time Dispatch (RTD) above $250/MWh decreased from 0.61 percent in August 2026 to 0.06 percent in September 2026, while the cumulative frequency of negative prices increased from 0.42 percent in August 2026 to 1.68 percent in September 2026. Average RTD DLAP prices across PGAE, SCE, SDGE, and VEA decreased relative to the previous month.
The cumulative total congestion rent for interties increased from $1.45 million in August 2026 to $3.11 million in September 2026. The majority of the congestion rents in September accrued on MALIN500_ISL (37.5%) and IPPUTAH_ITC (24.2%). Congestion rent on MALIN500_ISL increased from $21,089 in August 2026 to $1,165,156 in September 2026, while congestion rent on IPPUTAH_ITC increased from $409,523 in August 2026 to $751,646 in September 2026.
The Congestion Revenue Rights (CRR) net monthly balancing surplus in September was $19,622,091. The auction revenues credited to the balancing account for September were $8,596,107. As a result, the balancing account had a surplus of approximately $28.218 million compared to $25.922 million in the previous month, which was allocated to measured demand.
In September, the monthly Integrated Forward Market (IFM) average procurement decreased for regulation down, spinning reserves, and non-spinning reserves, while increasing for regulation up compared to the previous month. The monthly IFM average prices increased for regulation down, while decreasing for regulation up, spinning reserves, and non-spinning reserves compared to the previous month.
The total Bid Cost Recovery (BCR) decreased from $8.33 million in August 2026 to $6.59 million in September 2026. Out of the total monthly bid cost recovery payment in September, the Integrated Forward Market (IFM) market contributed 32.0 percent and Real-Time Market (RTM) contributed 68.0 percent of the total bid cost recovery payment.
Real-Time Imbalance Energy Offset (RTIEO) increased from -$5.16 million in August 2026 to $0.83 million in September 2026. Real-Time Congestion Offset (RTCO) increased from $29.34 million in August 2026 to $34.19 million in September 2026.
The monthly exceptional dispatch uplift payments increased from -$21,617 in August 2026 to $43,880 in September 2026.
The number of market disruptions increased from 26 in August 2026 to 31 in September 2026. On September 14, there were 9 (2 FMM, 1 Hour-Ahead Scheduling Process (HASP), 6 RTD) disruptions.
The total volume of exceptional dispatch increased from 45,706 MWh in August 2026 to 64,296 MWh in September 2026.
The curtailment of renewable energy increased in September 2026 compared to the previous month. Most curtailments continued to be solar.
Flexible ramping up uncertainty payment decreased from $790,037 in August 2026 to $260,541 in September 2026. Flexible ramping down uncertainty payment decreased from $132,865 in August 2026 to $36,850 in September 2026.
Western Energy Imbalance Market (WEIM) performance:
Total WEIM RTIEO decreased from $11.24 million in August 2026 to $3.38 million in September 2026. Total WEIM RTCO decreased from -$0.04 million in August 2026 to -$0.68 million in September 2026.
The cumulative frequency of FMM Energy Imbalance Market Load Aggregation Point (ELAP) prices above $250/MWh decreased from 0.37 percent in August 2026 to 0.12 percent in September 2026. The cumulative frequency of negative FMM ELAP prices decreased from 1.32 percent in August 2026 to 0.21 percent in September 2026.
The cumulative frequency of RTD ELAP prices above $250/MWh decreased from 0.42 percent in August 2026 to 0.08 percent in September 2026. The cumulative frequency of negative RTD ELAP prices decreased from 1.31 percent in August 2026 to 0.13 percent in September 2026.
Total WEIM BCR decreased from $2.57 million in August 2026 to $1.71 million in September 2026.
Total flexible ramping up uncertainty payment decreased from $1.97 million in August 2026 to $0.70 million in September 2026.
Total flexible ramping down uncertainty payment decreased from $294,392 in August 2026 to $82,559 in September 2026.
Total forecast payment increased from -$66,338 in August 2026 to $62,157 in September 2026.
| Month | WEIM | FMM ELAP Prices | RTD ELAP Prices | Price Difference |
|---|---|---|---|---|
| 2026-09 | AVA | $34.74 | $36.02 | -$1.27 |
| 2026-09 | AVRN | $37.09 | $37.70 | -$0.62 |
| 2026-09 | AZPS | $31.10 | $32.62 | -$1.52 |
| 2026-09 | BANC | $44.91 | $45.34 | -$0.43 |
| 2026-09 | BCHA | $25.10 | $25.81 | -$0.71 |
| 2026-09 | BHBA | $31.79 | $32.78 | -$1.00 |
| 2026-09 | BPAT | $39.21 | $38.20 | $1.01 |
| 2026-09 | EPE | $32.75 | $38.99 | -$6.24 |
| 2026-09 | GWA | $33.27 | $35.95 | -$2.68 |
| 2026-09 | IPCO | $34.25 | $35.47 | -$1.23 |
| 2026-09 | LADWP | $43.25 | $46.63 | -$3.38 |
| 2026-09 | NEVP | $33.90 | $35.17 | -$1.26 |
| 2026-09 | NWMT | $33.26 | $34.79 | -$1.53 |
| 2026-09 | PACE | $32.65 | $34.07 | -$1.42 |
| 2026-09 | PACW | $36.15 | $36.94 | -$0.80 |
| 2026-09 | PGE | $37.77 | $37.64 | $0.14 |
| 2026-09 | PNM | $31.63 | $33.16 | -$1.54 |
| 2026-09 | PSEI | $36.30 | $37.12 | -$0.81 |
| 2026-09 | SCL | $36.31 | $37.12 | -$0.81 |
| 2026-09 | SRP | $31.33 | $32.91 | -$1.58 |
| 2026-09 | TEPC | $31.48 | $35.55 | -$4.06 |
| 2026-09 | TIDC | $47.37 | $47.41 | -$0.04 |
| 2026-09 | TPWR | $36.31 | $37.13 | -$0.82 |
| 2026-09 | WALC | $31.29 | $32.74 | -$1.45 |