Shadow-day · stage 2 of 4 · intraday market
IDM re-clear · hour 09 · 2026-05-29
Stage status timestamp (IDM re-cleared): 2026-05-29T10:25:00Z
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
R854.47 / MWh
IDM SMP
R854.47 / MWh
Residual gap re-cleared
249.7 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 | -15.6% | 253.1 | -46.9 | re-bid window → |
| Eskom Holdings — coal fleet (Generator) | 28221.0 | — | 28221.0 | — | — |
| IPP — solar BW5 (Generator) | 1127.0 | -4.1% | 1080.5 | -46.5 | — |
| IPP — wind plant (Generator) | 1352.0 | -11.6% | 1195.7 | -156.3 | 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) | 249.7 | R854.47 |
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=9 seed=42 [clearHour] tieBreak=price_asc → ts_asc → party_id_asc [clearHour] demand_mw_min=1860000 [clearHour] accept offer=o-09-solar party=gen_ipp_solar_bw5_01 price=36310c volume=67620 cumulative=67620 [clearHour] accept offer=o-09-renew-agg party=agg_renewables_01 price=40878c volume=18000 cumulative=85620 [clearHour] accept offer=o-09-wind party=gen_ipp_wind_01 price=46598c volume=81120 cumulative=166740 [clearHour] accept offer=o-09-coal party=gen_eskom_coal_01 price=85447c volume=1693260 cumulative=1860000 [clearHour] SMP=85447c marginal=gen_eskom_coal_01 — IDM — [reclearIntraday] day=2026-05-29 hour=9 seed=42 [reclearIntraday] slip party=agg_renewables_01 -15.6% dam=18000 revised=15188 gap+=2812 [reclearIntraday] slip party=gen_ipp_solar_bw5_01 -4.1% dam=67620 revised=64827 gap+=2793 [reclearIntraday] slip party=gen_ipp_wind_01 -11.6% dam=81120 revised=71742 gap+=9378 [reclearIntraday] residual_gap=14983 backfilled=14983 uncovered=0 idm_smp=85447c backfill_awards=1