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
R847.35 / MWh
IDM SMP
R847.35 / MWh
Residual gap re-cleared
194.1 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 | -16.0% | 251.9 | -48.1 | re-bid window → |
| Eskom Holdings — coal fleet (Generator) | 27215.0 | — | 27215.0 | — | — |
| IPP — solar BW5 (Generator) | 1590.0 | 0.8% | 1603.3 | — | — |
| IPP — wind plant (Generator) | 1895.0 | -7.7% | 1749.0 | -145.9 | 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) | 194.1 | R847.35 |
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-solar party=gen_ipp_solar_bw5_01 price=37347c volume=95400 cumulative=95400 [clearHour] accept offer=o-11-renew-agg party=agg_renewables_01 price=40384c volume=18000 cumulative=113400 [clearHour] accept offer=o-11-wind party=gen_ipp_wind_01 price=45313c volume=113700 cumulative=227100 [clearHour] accept offer=o-11-coal party=gen_eskom_coal_01 price=84735c volume=1632900 cumulative=1860000 [clearHour] SMP=84735c marginal=gen_eskom_coal_01 — IDM — [reclearIntraday] day=2026-05-29 hour=11 seed=42 [reclearIntraday] slip party=agg_renewables_01 -16.0% dam=18000 revised=15112 gap+=2888 [reclearIntraday] slip party=gen_ipp_wind_01 -7.7% dam=113700 revised=104943 gap+=8757 [reclearIntraday] residual_gap=11645 backfilled=11645 uncovered=0 idm_smp=84735c backfill_awards=1