Shadow-day · stage 2 of 4 · intraday market
IDM re-clear · hour 19 · 2026-05-29
Stage status timestamp (IDM re-cleared): 2026-05-29T20:25:00Z
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
R1086.16 / MWh
IDM SMP
R1086.16 / MWh
Residual gap re-cleared
371.6 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 | -7.1% | 2787.0 | -213.0 | re-bid window → |
| IPP — battery storage (BESS) (Generator) | 1775.0 | — | 1775.0 | — | — |
| Eskom Holdings — coal fleet (Generator) | 30000.0 | — | 30000.0 | — | — |
| IPP — wind plant (Generator) | 1225.0 | -12.9% | 1066.4 | -158.6 | re-bid window → |
IDM backfill awards
Supply re-dispatched to cover the residual gap, paid at the IDM SMP.
| Party | MWh | Price (R/MWh) |
|---|---|---|
| IPP — battery storage (BESS) (Generator) | 371.6 | R1086.16 |
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=19 seed=42 [clearHour] tieBreak=price_asc → ts_asc → party_id_asc [clearHour] demand_mw_min=2160000 [clearHour] accept offer=o-19-renew-agg party=agg_renewables_01 price=39757c volume=180000 cumulative=180000 [clearHour] accept offer=o-19-wind party=gen_ipp_wind_01 price=46650c volume=73500 cumulative=253500 [clearHour] accept offer=o-19-coal party=gen_eskom_coal_01 price=85848c volume=1800000 cumulative=2053500 [clearHour] accept offer=o-19-bess party=gen_bess_ipp_01 price=108616c volume=106500 cumulative=2160000 [clearHour] SMP=108616c marginal=gen_bess_ipp_01 — IDM — [reclearIntraday] day=2026-05-29 hour=19 seed=42 [reclearIntraday] slip party=agg_renewables_01 -7.1% dam=180000 revised=167221 gap+=12779 [reclearIntraday] slip party=gen_ipp_wind_01 -12.9% dam=73500 revised=63983 gap+=9517 [reclearIntraday] residual_gap=22296 backfilled=22296 uncovered=0 idm_smp=108616c backfill_awards=1