Systematic attribution of evening demand growth (19:00–01:00) across consumer sectors — residential, commercial, industrial — and quantification of peak shaving potential under three commercial closing-time interventions. Based on ISMO hourly metered demand data (Jul 2024–Jun 2025) and NEPRA State of Industry Report 2024 sector consumption shares.
Pakistan's power grid exhibits a persistent evening demand spike that is structurally distinct from most developed markets. The NTDC system (excluding Karachi/KE) carries an average annual peak of 15,591 MW at H20 (20:00–21:00), against a midday trough of ~12,670 MW at H12 — a 2,921 MW intra-day swing on annual average. This swing is driven by three overlapping demand surges: residential cooking and air-conditioning load building through H18–H22, commercial activity peaking in bazaars and restaurants between H19–H21, and deferred post-shedding rebound demand.
Critically, the evening peak hour shifts with the season. In winter (Dec–Feb), peak arrives early at H17–H18 (~12,367 MW). In summer (Jun–Sep), the peak migrates to H22–H23 (~20,081 MW) as residential AC load dominates well into the night. Commercial load peaks earlier than residential in all seasons, making commercial closing mandates a structurally targeted intervention for the H20–H22 window.
| Season | Peak Hour | Peak MW (Excl. KE) | Trough MW | Evening Ramp | Ramp % |
|---|---|---|---|---|---|
| Summer (Jun–Sep) | H23 (11pm–12am) | 20,081 | 16,448 | 3,633 | +22.1% |
| Spring (Mar–May) | H20 (8pm–9pm) | 15,985 | 11,466 | 4,519 | +39.4% |
| Autumn (Oct–Nov) | H17 (5pm–6pm) | 13,540 | 11,228 | 2,245 | +20.0% |
| Winter (Dec–Feb) | H18 (6pm–7pm) | 12,367 | 9,511 | 2,856 | +30.0% |
| Full Year Average | H20 (8pm–9pm) | 15,591 | 12,670 | 2,921 | +23.1% |
Monthly evolution (Jul 2024–Jan 2026): System demand has grown materially year-on-year. July 2025 peak demand (H23 = 21,238 MW excl. KE) exceeded July 2024 (H23 = 21,386 MW) at similar levels, while January 2026 (H18 = 14,236 MW) significantly exceeds January 2025 (H18 = 12,816 MW), indicating structural demand recovery following the 2023–24 contraction driven by tariff shock.
| Hour | Residential MW | Commercial MW | Industrial MW | Agriculture MW | Others MW | Total MW | Com% of Total |
|---|
† National totals (incl. KE). Load shapes applied to FY2024 NEPRA sector consumption data. Commercial load shape calibrated to Pakistan bazaar/restaurant/retail operating patterns (10am–11pm). Industrial shape reflects continuous process + day-shift mix.
The critical insight for commercial closing policy is not the annual average commercial share — it is the within-peak-window share. Commercial consumption constitutes 8.3% of annual billed units nationally, but at H19–H20 its share of the system load rises to 12.5–12.6% (national, annual average). In summer, with commercial air-conditioning adding ~35% to the commercial sector's demand, this share rises further to 13.7–14.3% at those hours.
More importantly, commercial load's hour-by-hour profile is distinct: it peaks earlier in the evening than residential (bazaars/restaurants peak H19–H20) and decays faster after H21. Residential demand by contrast remains elevated through H22–H23 (AC compressors running all night in summer). This temporal separation makes targeted commercial closures a precise intervention: they affect peak commercial load without disturbing residential behaviour.
| Time | Residential | Commercial | Industrial | Agriculture | Others | Total | Com% Share | Res% Share |
|---|---|---|---|---|---|---|---|---|
| H18 (6–7pm) | 8,504 | 1,965 | 3,005 | 1,199 | 1,188 | 15,860 | 11.5% | 53.6% |
| H19 (7–8pm) ← Com Peak | 9,586 | 2,217 | 2,855 | 1,199 | 1,108 | 16,965 | 12.6% | 56.5% |
| H20 (8–9pm) ← System Peak | 9,741 | 2,217 | 2,855 | 1,199 | 1,108 | 17,120 | 12.5% | 56.9% |
| H21 (9–10pm) | 9,277 | 1,889 | 2,779 | 1,079 | 1,108 | 16,133 | 10.7% | 57.5% |
| H22 (10–11pm) | 8,195 | 1,386 | 2,704 | 959 | 1,267 | 14,511 | 9.5% | 56.5% |
| H23 (11pm–12am) | 7,422 | 882 | 2,855 | 839 | 1,372 | 13,369 | 6.6% | 55.5% |
| H00 (12–1am) | 6,494 | 126 | 3,230 | 719 | 1,452 | 12,021 | 1.0% | 54.0% |
Three scenarios are modelled: mandatory commercial closure at 8pm, 9pm, and 10pm. For each scenario, the reduction is computed as 75% of commercial load at the affected hours — the "switchable" component (active lighting, HVAC, operational equipment). The residual 25% accounts for security lighting, refrigeration, and 24/7 establishments (petrol stations, pharmacies, hospitals) that cannot comply. The transition hour is modelled at 50% compliance to reflect wind-down effects.
Note: closure mandates eliminate commercial load from the enforcement hour forward. The system peak hour itself changes depending on when the mandate kicks in — under an 8pm mandate, the new peak becomes H19 (~2pm later the commercial ramp reversal begins).
| Metric | Baseline (No Intervention) | Close at 8pm | Close at 9pm | Close at 10pm |
|---|---|---|---|---|
| Annual avg peak MW (H20, national) | 17,737 | 16,074 −1,663 | 16,320 −1,417 | 16,698 −1,039 |
| Reduction as % of system (annual avg) | — | 9.4% | 8.0% | 6.1% |
| Summer peak MW at H20 (national) | 21,885 | 19,640 −2,245 | 19,972 −1,913 | 20,482 −1,403 |
| Summer reduction as % of system | — | 10.3% | 8.6% | 6.2% |
| Winter peak MW at H18 (national) | 14,080 | 12,857 −1,223 | 13,130 −950 | 13,606 −474 |
| Daily energy shifted (MWh, H19 onwards) | — | 5,611 | 3,949 | 2,409 |
| Annual energy impact (GWh) | — | 2,048 | 1,441 | 879 |
| Estimated marginal cost saving (PKR/kWh ≈ 20–24) | — | ~PKR 41–49 Bn | ~PKR 29–35 Bn | ~PKR 18–21 Bn |
| Peak MW equivalent in capacity savings | — | ~1,663 MW displaced | ~1,417 MW | ~1,039 MW |
| Enforcement complexity | — | HIGH — cuts evening trade | MEDIUM | LOWER — post-dinner |
The commercial closing intervention interacts differently with each season because: (1) the system peak hour shifts seasonally — evening in spring/winter, late night in summer; (2) commercial air-conditioning load varies (highest in summer, lowest in winter); and (3) the marginal cost of the electricity displaced varies significantly by season and hour, with summer evening marginal costs reaching 22–28 PKR/kWh versus 4–12 PKR/kWh in off-peak hours.
| Season | Commercial Scaling vs. Annual | Com MW at H20 | System MW at H20 | Com% of System | 8pm Closure Saves (MW) | 9pm Closure Saves (MW) |
|---|---|---|---|---|---|---|
| Summer (Jun–Sep) | +35% (heavy AC) | 2,993 | 21,885 | 13.7% | 2,245 | 1,913 |
| Spring (Mar–May) | +5% (moderate AC) | 2,328 | 18,186 | 12.8% | 1,746 | 1,488 |
| Autumn (Oct–Nov) | −5% (transitional) | 2,106 | 15,221 | 13.8% | 1,580 | 1,347 |
| Winter (Dec–Feb) | −15% (minimal AC) | 1,884 | 13,383 | 14.1% | 1,413 | 1,204 |
| Annual Average | Base (1.00×) | 2,217 | 17,737 | 12.5% | 1,663 | 1,417 |
| Month | H18 | H19 | H20 | H21 | H22 | H23 |
|---|---|---|---|---|---|---|
| Mar/Apr 2025 | 23.90 | 24.05 | 23.38 | 24.08 | 21.50 | 4.81 |
| Jul 2025 | 14.56 | 15.93 | 20.68 | 21.91 | 22.48 | 27.83 |
| Sep 2023 | ~28 | ~28 | ~28 | ~28 | ~27 | ~28 |
Summer marginal costs peak at H23 (midnight) rather than H20. This reflects thermal dispatch into extended AC load. A commercial closure at 8pm sheds load at H20 when MC = 20–24 PKR/kWh — the sweet spot for avoided cost savings.
In summer, the system peak occurs at H22–H23 (11pm–1am), driven by residential AC that runs all night as buildings retain heat. Even a complete commercial closure at 8pm would reduce H20 demand by ~2,245 MW but the summer system peak (H23 = 20,081 MW excl. KE) remains driven by residential load which commercial policy cannot address.
The correct framing: commercial closing mandates are a peak flattening instrument, not a peak elimination strategy. They compress the H19–H21 demand surge, reduce the thermal dispatch quantity needed during those hours, and potentially defer activation of the most expensive marginal units — but they cannot substitute for structural solutions like time-of-use tariff reform, demand response programs, or battery storage.
Complementary interventions: A 9pm commercial closing mandate combined with a residential ToU tariff that prices H21–H23 at 1.5–2× daytime rates would address both the commercial peak (H19–H21) and the residential overnight AC load simultaneously.