Impact of PV orientation on energy yield and power variability: a comparative study of true south and east–west industrial rooftop systems
Year: 2026
Type: article
Abstract: Rooftop photovoltaic (PV) deployment in energy-intensive industry requires an orientation choice that balances energy yield, roof-area productivity and power quality. This study compares true-south (TS) and east-west (EW) PV configurations for an industrial rooftop in Nooriabad, Pakistan (25.05° N, 67.86° E), combining PVsyst simulation with one year of field data logged at 1 s resolution and aggregated to 1 h and 10 min. Two constraints were examined: fixed capacity (1462 kWp DC, 1250 kW AC) and fixed roof area (7568 m 2 ). A tilt sweep from 1° to 20° gave a TS optimum of 15° at a specific yield of 1663 kWh/kWp, whereas EW varied by less than 1% across the range, so 5° was adopted for structural and drainage reasons. Under fixed capacity, TS produced 2.431 GWh/yr against 2.294 GWh/yr for EW, a 6.0 % advantage, while EW required 6.1 % less roof area (7858 against 8369 m 2 ). Under fixed area, EW reached 2.569 GWh/yr against 2.276 GWh/yr, a 12.9 % advantage, raising energy density from 300.8 to 339.5 kWh/m 2 /yr. Measured 10 min power variance was 5.44 × 10 4 kW 2 for TS and 5.09 × 10 4 kW 2 for EW, a 6.4 % reduction, and the largest observed excursion reached 49.1 % of rated power within 10 min. Levelized cost of electricity was 0.028 USD/kWh for TS and 0.027 USD/kWh for EW, against displaced gas-engine generation at 38.0 PKR/kWh, a net 36.0 PKR/kWh after solar O&M. TS therefore maximizes yield per installed watt, whereas EW maximizes yield per square meter and delivers a measurably smoother profile.
Source: Renewable energy focus
Language: English
Field: Energy
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $1,790
OpenAlex ID: W7213638256