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.
Peak hour — no spare IDM supply. The residual gap exceeds the remaining unawarded supply, so 302.4 MWh cannot be backfilled intraday and falls through to balancing at the imbalance price. IDM SMP holds at the DAM SMP.
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 | -14.5% | 256.5 | -43.5 | re-bid window → |
| Cross-border — ZESA interconnect | 200.0 | — | 200.0 | — | — |
| Eskom Holdings — coal fleet (Generator) | 30000.0 | — | 30000.0 | — | — |
| Eskom Holdings — OCGT peaker (Generator) | 400.0 | — | 400.0 | — | — |
| IPP — solar BW5 (Generator) | 407.0 | 1.7% | 414.1 | — | — |
| IPP — wind plant (Generator) | 1505.0 | -17.2% | 1246.1 | -258.9 | re-bid window → |
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=36189c volume=24420 cumulative=24420 [clearHour] accept offer=o-18-renew-agg party=agg_renewables_01 price=40822c volume=18000 cumulative=42420 [clearHour] accept offer=o-18-wind party=gen_ipp_wind_01 price=43736c volume=90300 cumulative=132720 [clearHour] accept offer=o-18-coal party=gen_eskom_coal_01 price=84956c volume=1800000 cumulative=1932720 [clearHour] accept offer=o-18-zesa party=cb_zesa_synthetic price=110833c volume=12000 cumulative=1944720 [clearHour] accept offer=o-18-ocgt party=gen_eskom_ocgt_01 price=219165c volume=24000 cumulative=1968720 [clearHour] SMP=219165c marginal=gen_eskom_ocgt_01 — IDM — [reclearIntraday] day=2026-05-29 hour=18 seed=42 [reclearIntraday] slip party=agg_renewables_01 -14.5% dam=18000 revised=15389 gap+=2611 [reclearIntraday] slip party=gen_ipp_wind_01 -17.2% dam=90300 revised=74766 gap+=15534 [reclearIntraday] residual_gap=18145 backfilled=0 uncovered=18145 idm_smp=219165c backfill_awards=0