Shadow-day · stage 2 of 4 · intraday market
IDM re-clear · hour 11 · 2026-05-29
Stage status timestamp (IDM re-cleared): 2026-05-29T12:25:00Z
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
R862.87 / MWh
IDM SMP
R862.87 / MWh
Residual gap re-cleared
584.9 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 | -16.0% | 2518.6 | -481.4 | re-bid window → |
| Eskom Holdings — coal fleet (Generator) | 25066.0 | — | 25066.0 | — | — |
| IPP — solar BW5 (Generator) | 1590.0 | 0.8% | 1603.3 | — | — |
| IPP — wind plant (Generator) | 1344.0 | -7.7% | 1240.5 | -103.5 | 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) | 584.9 | R862.87 |
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=11 seed=42 [clearHour] tieBreak=price_asc → ts_asc → party_id_asc [clearHour] demand_mw_min=1860000 [clearHour] accept offer=o-11-renew-agg party=agg_renewables_01 price=38713c volume=180000 cumulative=180000 [clearHour] accept offer=o-11-solar party=gen_ipp_solar_bw5_01 price=39890c volume=95400 cumulative=275400 [clearHour] accept offer=o-11-wind party=gen_ipp_wind_01 price=43519c volume=80640 cumulative=356040 [clearHour] accept offer=o-11-coal party=gen_eskom_coal_01 price=86287c volume=1503960 cumulative=1860000 [clearHour] SMP=86287c marginal=gen_eskom_coal_01 — IDM — [reclearIntraday] day=2026-05-29 hour=11 seed=42 [reclearIntraday] slip party=agg_renewables_01 -16.0% dam=180000 revised=151118 gap+=28882 [reclearIntraday] slip party=gen_ipp_wind_01 -7.7% dam=80640 revised=74429 gap+=6211 [reclearIntraday] residual_gap=35093 backfilled=35093 uncovered=0 idm_smp=86287c backfill_awards=1