Volume 62

Effects of Climatic Factors on Hydropower Generation at Kihansi Power Plant Kihedu JH, Masunga RM

Abstract

This paper examined how critical climatic factors, specifically rainfall, temperature, and humidity, affect hydropower generation at the Kihansi Hydropower Plant in Tanzania. The analysis was based on data collected from 2010 to 2023, by using Principal Component Analysis, Pearson correlation, and multiple linear regression analysis, processed through SPSS software.
The PCA results revealed that rainfall, temperature, and humidity together explained 79.09% of the total variation in hydropower generation at the plant. Notably, rainfall and humidity alone accounted for 53.28%, while temperature contributed 25.94%. This means that changes in these climatic variables account for nearly 80% of the fluctuations in power generation, a critical insight for operational planning.
Pearson correlation analysis showed a strong positive relationship between rainfall and humidity (r = 0.541, p < 0.001), confirming that higher rainfall periods are typically accompanied by increased humidity, which influences water availability. The correlation between rainfall and temperature was weak and negative (r = -0.100, p = 0.198), while humidity and temperature showed no significant relationship (r = 0.030, p = 0.704). The multiple linear regression analysis shows that rainfall had a strong positive impact (β = 0.844, p < 0.001), with a 1 mm increase raising generation by 0.180 MW. Temperature showed a significant negative effect (β = -0.114, p = 0.002), where a 1°C rise reduced output by 2.180 MW due to higher evaporation. Humidity had a positive but insignificant effect (β = 0.041, p = 0.344). The model explained 78.5% of the total variance in hydropower generation (R² = 0.785). This confirms that rainfall is the most influential factor at Kihansi.

Keywords hydropower generation, climate change, Pearson correlation analysis, multiple linear regression