Shadow-day · stage 2 of 4 · intraday market
IDM re-clear · hour 17 · 2026-05-29
Stage status timestamp (IDM re-cleared): 2026-05-29T18:25:00Z
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
R1091.95 / MWh
IDM SMP
R1091.95 / MWh
Residual gap re-cleared
625.5 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 | -14.2% | 2575.4 | -424.6 | re-bid window → |
| IPP — battery storage (BESS) (Generator) | 696.0 | — | 696.0 | — | — |
| Eskom Holdings — coal fleet (Generator) | 30000.0 | — | 30000.0 | — | — |
| IPP — solar BW5 (Generator) | 790.0 | -8.3% | 724.1 | -65.9 | re-bid window → |
| IPP — wind plant (Generator) | 1514.0 | -8.9% | 1379.0 | -135.0 | 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) | 625.5 | R1091.95 |
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=17 seed=42 [clearHour] tieBreak=price_asc → ts_asc → party_id_asc [clearHour] demand_mw_min=2160000 [clearHour] accept offer=o-17-solar party=gen_ipp_solar_bw5_01 price=36941c volume=47400 cumulative=47400 [clearHour] accept offer=o-17-renew-agg party=agg_renewables_01 price=39301c volume=180000 cumulative=227400 [clearHour] accept offer=o-17-wind party=gen_ipp_wind_01 price=45357c volume=90840 cumulative=318240 [clearHour] accept offer=o-17-coal party=gen_eskom_coal_01 price=85185c volume=1800000 cumulative=2118240 [clearHour] accept offer=o-17-bess party=gen_bess_ipp_01 price=109195c volume=41760 cumulative=2160000 [clearHour] SMP=109195c marginal=gen_bess_ipp_01 — IDM — [reclearIntraday] day=2026-05-29 hour=17 seed=42 [reclearIntraday] slip party=agg_renewables_01 -14.2% dam=180000 revised=154527 gap+=25473 [reclearIntraday] slip party=gen_ipp_solar_bw5_01 -8.3% dam=47400 revised=43444 gap+=3956 [reclearIntraday] slip party=gen_ipp_wind_01 -8.9% dam=90840 revised=82741 gap+=8099 [reclearIntraday] residual_gap=37528 backfilled=37528 uncovered=0 idm_smp=109195c backfill_awards=1