Shadow-day · stage 2 of 4 · intraday market
IDM re-clear · hour 12 · 2026-05-29
Stage status timestamp (IDM re-cleared): 2026-05-29T13:25:00Z
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
R847.99 / MWh
IDM SMP
R847.99 / MWh
Residual gap re-cleared
431.4 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 | 300.0 | -7.5% | 277.6 | -22.4 | re-bid window → |
| Eskom Holdings — coal fleet (Generator) | 27893.0 | — | 27893.0 | — | — |
| IPP — solar BW5 (Generator) | 1688.0 | -14.4% | 1445.4 | -242.6 | re-bid window → |
| IPP — wind plant (Generator) | 1119.0 | -14.9% | 952.5 | -166.5 | 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) | 431.4 | R847.99 |
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=12 seed=42 [clearHour] tieBreak=price_asc → ts_asc → party_id_asc [clearHour] demand_mw_min=1860000 [clearHour] accept offer=o-12-solar party=gen_ipp_solar_bw5_01 price=38780c volume=101280 cumulative=101280 [clearHour] accept offer=o-12-renew-agg party=agg_renewables_01 price=41976c volume=18000 cumulative=119280 [clearHour] accept offer=o-12-wind party=gen_ipp_wind_01 price=46372c volume=67140 cumulative=186420 [clearHour] accept offer=o-12-coal party=gen_eskom_coal_01 price=84799c volume=1673580 cumulative=1860000 [clearHour] SMP=84799c marginal=gen_eskom_coal_01 — IDM — [reclearIntraday] day=2026-05-29 hour=12 seed=42 [reclearIntraday] slip party=agg_renewables_01 -7.5% dam=18000 revised=16657 gap+=1343 [reclearIntraday] slip party=gen_ipp_solar_bw5_01 -14.4% dam=101280 revised=86726 gap+=14554 [reclearIntraday] slip party=gen_ipp_wind_01 -14.9% dam=67140 revised=57150 gap+=9990 [reclearIntraday] residual_gap=25887 backfilled=25887 uncovered=0 idm_smp=84799c backfill_awards=1