Performance Analysis of Wind Turbines Using Environmental Parameters: A Six-Decade Historical, Data-Driven and Model-Based Assessment of Wind Energy Potential and Turbine Performance Dynamics at Kohat Station, Pakistan, 1954–2010

Abstract

Local wind speed and ambient conditions determine how much energy a wind turbine could deliver, but long historical records are rarely examined together with a transparent turbine model. This study assesses the estimated wind-energy potential of Kohat, Pakistan, from a workbook of monthly observations for 1954–2010 taken at 08:00 and 17:00 (684 records per time; 645 and 633 valid). The origin of the workbook could not be established, so the records are treated as an attributed dataset and not as a verified station archive. Wind speed, direction, temperature, relative humidity and calculated air density were combined with a hypothetical reference turbine (rotor diameter 90 m, hub height 80 m, Cp = 0.45, cut-in 3 m/s, 15% assumed loss) to derive wind power density (WPD) and modelled power. No measured turbine output exists, so all results are model estimates. Mean wind speed was 1.59 and 2.22 m/s and mean WPD was 3.97 and 13.43 W/m2 at 08:00 and 17:00. The cut-in speed was reached in 2.5% and 22.4% of valid months, giving modelled capacity factors of 0.05% and 0.92% when speeds are used as supplied (no height correction). Generation at 17:00 was concentrated in May–August. Annual means declined over the record, and the last 23 months showed a level shift that carries 31–37% of the estimated energy; both features need metadata checks. Hub-height extrapolation and cut-in speed dominated the sensitivity results, whereas Cp, loss allowance and density acted proportionally. On this dataset Kohat is a low-wind site, and the numerical yields are lower-bound, assumption-conditional estimates.