Shadow-day · stage 2 of 4 · intraday market
IDM re-clear · hour 16 · 2026-05-29
Stage status timestamp (IDM re-cleared): 2026-05-29T17:25:00Z
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
R847.37 / MWh
IDM SMP
R847.37 / MWh
Residual gap re-cleared
555.0 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 | 3000.0 | -12.8% | 2617.5 | -382.5 | re-bid window → |
| Eskom Holdings — coal fleet (Generator) | 25630.0 | — | 25630.0 | — | — |
| IPP — solar BW5 (Generator) | 1127.0 | -8.9% | 1026.3 | -100.7 | re-bid window → |
| IPP — wind plant (Generator) | 1243.0 | -5.8% | 1171.3 | -71.7 | 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) | 555.0 | R847.37 |
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=16 seed=42 [clearHour] tieBreak=price_asc → ts_asc → party_id_asc [clearHour] demand_mw_min=1860000 [clearHour] accept offer=o-16-solar party=gen_ipp_solar_bw5_01 price=38744c volume=67620 cumulative=67620 [clearHour] accept offer=o-16-renew-agg party=agg_renewables_01 price=39594c volume=180000 cumulative=247620 [clearHour] accept offer=o-16-wind party=gen_ipp_wind_01 price=44673c volume=74580 cumulative=322200 [clearHour] accept offer=o-16-coal party=gen_eskom_coal_01 price=84737c volume=1537800 cumulative=1860000 [clearHour] SMP=84737c marginal=gen_eskom_coal_01 — IDM — [reclearIntraday] day=2026-05-29 hour=16 seed=42 [reclearIntraday] slip party=agg_renewables_01 -12.8% dam=180000 revised=157049 gap+=22951 [reclearIntraday] slip party=gen_ipp_solar_bw5_01 -8.9% dam=67620 revised=61576 gap+=6044 [reclearIntraday] slip party=gen_ipp_wind_01 -5.8% dam=74580 revised=70278 gap+=4302 [reclearIntraday] residual_gap=33297 backfilled=33297 uncovered=0 idm_smp=84737c backfill_awards=1