Shadow-day · stage 2 of 4 · intraday market
IDM re-clear · hour 08 · 2026-05-29
Stage status timestamp (IDM re-cleared): 2026-05-29T09:25:00Z
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
R847.24 / MWh
IDM SMP
R847.24 / MWh
Residual gap re-cleared
423.0 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 | -14.7% | 256.0 | -44.0 | re-bid window → |
| Eskom Holdings — coal fleet (Generator) | 27980.0 | — | 27980.0 | — | — |
| IPP — solar BW5 (Generator) | 790.0 | -15.5% | 667.2 | -122.8 | re-bid window → |
| IPP — wind plant (Generator) | 1930.0 | -13.3% | 1673.8 | -256.1 | 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) | 423.0 | R847.24 |
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=8 seed=42 [clearHour] tieBreak=price_asc → ts_asc → party_id_asc [clearHour] demand_mw_min=1860000 [clearHour] accept offer=o-08-solar party=gen_ipp_solar_bw5_01 price=36549c volume=47400 cumulative=47400 [clearHour] accept offer=o-08-renew-agg party=agg_renewables_01 price=38443c volume=18000 cumulative=65400 [clearHour] accept offer=o-08-wind party=gen_ipp_wind_01 price=46769c volume=115800 cumulative=181200 [clearHour] accept offer=o-08-coal party=gen_eskom_coal_01 price=84724c volume=1678800 cumulative=1860000 [clearHour] SMP=84724c marginal=gen_eskom_coal_01 — IDM — [reclearIntraday] day=2026-05-29 hour=8 seed=42 [reclearIntraday] slip party=agg_renewables_01 -14.7% dam=18000 revised=15359 gap+=2641 [reclearIntraday] slip party=gen_ipp_solar_bw5_01 -15.5% dam=47400 revised=40030 gap+=7370 [reclearIntraday] slip party=gen_ipp_wind_01 -13.3% dam=115800 revised=100431 gap+=15369 [reclearIntraday] residual_gap=25380 backfilled=25380 uncovered=0 idm_smp=84724c backfill_awards=1