Shadow-day · stage 2 of 4 · intraday market
IDM re-clear · hour 10 · 2026-05-29
Stage status timestamp (IDM re-cleared): 2026-05-29T11:25:00Z
Illustrative re-clearing — production MMS runs a full intraday SCED. The IDM stage consumes the DAM result for this hour, applies each variable generator's revised forecast, and re-clears the residual gap.
DAM SMP
R851.80 / MWh
IDM SMP
R851.80 / MWh
Residual gap re-cleared
840.5 MWh
from forecast slip on variable plant
Forecast adjustments at the IDM gate
Variable generators (wind / solar / aggregated renewables) revise availability; a slip beyond −5% makes the seller IDM re-bid eligible (the forecast-slip story). Dispatchable plant shows 0% slip.
| Party | DAM award (MWh) | Forecast slip | Revised (MWh) | Gap (MWh) | Re-bid? |
|---|---|---|---|---|---|
| Aggregator — renewables pool | 3000.0 | -12.9% | 2612.9 | -387.1 | re-bid window → |
| Eskom Holdings — coal fleet (Generator) | 25311.0 | — | 25311.0 | — | — |
| IPP — solar BW5 (Generator) | 1399.0 | -18.6% | 1138.4 | -260.6 | re-bid window → |
| IPP — wind plant (Generator) | 1290.0 | -14.9% | 1097.2 | -192.8 | re-bid window → |
IDM backfill awards
Supply re-dispatched to cover the residual gap, paid at the IDM SMP.
| Party | MWh | Price (R/MWh) |
|---|---|---|
| Eskom Holdings — coal fleet (Generator) | 840.5 | R851.80 |
Commit this IDM re-clear to the append-only SHA-256 chain
(idm_re_cleared event). Best-effort: with no D1 binding bound
locally this degrades to a "not recorded" marker rather than failing.
Full DAM + IDM transcript
[clearHour] day=2026-05-29 hour=10 seed=42 [clearHour] tieBreak=price_asc → ts_asc → party_id_asc [clearHour] demand_mw_min=1860000 [clearHour] accept offer=o-10-solar party=gen_ipp_solar_bw5_01 price=36403c volume=83940 cumulative=83940 [clearHour] accept offer=o-10-renew-agg party=agg_renewables_01 price=40786c volume=180000 cumulative=263940 [clearHour] accept offer=o-10-wind party=gen_ipp_wind_01 price=44183c volume=77400 cumulative=341340 [clearHour] accept offer=o-10-coal party=gen_eskom_coal_01 price=85180c volume=1518660 cumulative=1860000 [clearHour] SMP=85180c marginal=gen_eskom_coal_01 — IDM — [reclearIntraday] day=2026-05-29 hour=10 seed=42 [reclearIntraday] slip party=agg_renewables_01 -12.9% dam=180000 revised=156773 gap+=23227 [reclearIntraday] slip party=gen_ipp_solar_bw5_01 -18.6% dam=83940 revised=68304 gap+=15636 [reclearIntraday] slip party=gen_ipp_wind_01 -14.9% dam=77400 revised=65830 gap+=11570 [reclearIntraday] residual_gap=50433 backfilled=50433 uncovered=0 idm_smp=85180c backfill_awards=1