Aggregator — renewables pool — IDM re-bid window
agg_renewables_01
When a variable plant's day-ahead forecast slips beyond −5% at the IDM gate, the seller can re-bid in the intraday market rather than fall straight into the (more expensive) balancing/imbalance settlement.
Implied under-delivery penalty: SMP × 1.15 or an R2 000/MWh floor, whichever is higher. The floor binds when the SMP is below R1 739,13/MWh. Illustrative, basis pending NERSA (Trading Rules R2 §07 placeholder).
Re-bid window · hour 13
IDM gate timestamp: 2026-05-29T14:25:00Z
Day-ahead award 3000.0 MWh; forecast slipped -19.7% to 2409.3 MWh available — a shortfall of 590.8 MWh. Do nothing and the imbalance bill is R1181500.00. There is 755.1 MWh of residual demand to re-bid into at an IDM SMP of R864.54/MWh.
24-hour forecast-slip ledger
| Hr | DAM award | Slip | Revised | Shortfall | Imbalance (do nothing) | Re-bid? |
|---|---|---|---|---|---|---|
| 00 | 3000.0 | -17.9% | 2464.1 | 535.9 | R1071833.33 | eligible |
| 01 | 3000.0 | 1.1% | 3034.1 | — | — | — |
| 02 | 3000.0 | -3.3% | 2899.8 | 100.2 | R200366.67 | — |
| 03 | 3000.0 | -19.1% | 2427.6 | 572.4 | R1144733.33 | eligible |
| 04 | 3000.0 | -16.0% | 2518.7 | 481.3 | R962633.33 | eligible |
| 05 | 3000.0 | 0.3% | 3009.8 | — | — | — |
| 06 | 3000.0 | -2.2% | 2934.9 | 65.1 | R130266.67 | — |
| 07 | 3000.0 | -9.8% | 2705.6 | 294.4 | R588766.67 | eligible |
| 08 | 3000.0 | -14.7% | 2559.8 | 440.2 | R880466.67 | eligible |
| 09 | 3000.0 | -15.6% | 2531.4 | 468.6 | R937200.00 | eligible |
| 10 | 3000.0 | -12.9% | 2612.9 | 387.1 | R774233.33 | eligible |
| 11 | 3000.0 | -16.0% | 2518.6 | 481.4 | R962733.33 | eligible |
| 12 | 3000.0 | -7.5% | 2776.2 | 223.8 | R447633.33 | eligible |
| 13 | 3000.0 | -19.7% | 2409.3 | 590.8 | R1181500.00 | eligible |
| 14 | 3000.0 | -3.7% | 2889.8 | 110.2 | R220366.67 | — |
| 15 | 3000.0 | -18.0% | 2461.1 | 539.0 | R1077900.00 | eligible |
| 16 | 3000.0 | -12.8% | 2617.5 | 382.5 | R765033.33 | eligible |
| 17 | 3000.0 | -14.2% | 2575.4 | 424.6 | R849100.00 | eligible |
| 18 | 3000.0 | -14.5% | 2564.8 | 435.2 | R870433.33 | eligible |
| 19 | 3000.0 | -7.1% | 2787.0 | 213.0 | R425966.67 | eligible |
| 20 | 3000.0 | -4.7% | 2860.0 | 140.0 | R279966.67 | — |
| 21 | 3000.0 | -13.4% | 2596.9 | 403.1 | R806100.00 | eligible |
| 22 | 3000.0 | -10.8% | 2675.6 | 324.4 | R648766.67 | eligible |
| 23 | 3000.0 | 3.4% | 3101.7 | — | — | — |