Shadow-day · stage 2 of 4 · intraday market
IDM re-clear · hour 18 · 2026-05-29
Stage status timestamp (IDM re-cleared): 2026-05-29T19:25:00Z
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
R1081.69 / MWh
IDM SMP
R1081.69 / MWh
Residual gap re-cleared
600.7 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 | 3000.0 | -14.5% | 2564.8 | -435.2 | re-bid window → |
| IPP — battery storage (BESS) (Generator) | 1631.0 | — | 1631.0 | — | — |
| Eskom Holdings — coal fleet (Generator) | 30000.0 | — | 30000.0 | — | — |
| IPP — solar BW5 (Generator) | 407.0 | 1.7% | 414.1 | — | — |
| IPP — wind plant (Generator) | 962.0 | -17.2% | 796.5 | -165.5 | re-bid window → |
IDM backfill awards
Supply re-dispatched to cover the residual gap, paid at the IDM SMP.
| Party | MWh | Price (R/MWh) |
|---|---|---|
| IPP — battery storage (BESS) (Generator) | 600.7 | R1081.69 |
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=18 seed=42 [clearHour] tieBreak=price_asc → ts_asc → party_id_asc [clearHour] demand_mw_min=2160000 [clearHour] accept offer=o-18-solar party=gen_ipp_solar_bw5_01 price=36499c volume=24420 cumulative=24420 [clearHour] accept offer=o-18-renew-agg party=agg_renewables_01 price=39255c volume=180000 cumulative=204420 [clearHour] accept offer=o-18-wind party=gen_ipp_wind_01 price=44256c volume=57720 cumulative=262140 [clearHour] accept offer=o-18-coal party=gen_eskom_coal_01 price=85779c volume=1800000 cumulative=2062140 [clearHour] accept offer=o-18-bess party=gen_bess_ipp_01 price=108169c volume=97860 cumulative=2160000 [clearHour] SMP=108169c marginal=gen_bess_ipp_01 — IDM — [reclearIntraday] day=2026-05-29 hour=18 seed=42 [reclearIntraday] slip party=agg_renewables_01 -14.5% dam=180000 revised=153887 gap+=26113 [reclearIntraday] slip party=gen_ipp_wind_01 -17.2% dam=57720 revised=47791 gap+=9929 [reclearIntraday] residual_gap=36042 backfilled=36042 uncovered=0 idm_smp=108169c backfill_awards=1