Abstract:
ABSTRACT
The impacts of climate variability and change including the influence of ENSO are real
and affect several productive economic sectors such as agriculture, water, forest resources
and energy. Energy is a very important sector for achieving sustainable development.
Ghana has continuously relied heavily on Akosombo and Kpong hydropower stations to
supply electricity for household and industrial use. Historical records have shown that
variability and change in rainfall including the influence of ENSO has affected lake water
levels and consequently the amount of power generated by these hydropower projects. This
led to power crises and periodic blackouts in 1984, 1998, 2003, and 2007. The current
power crisis has been ongoing for the past three years. This study therefore sought to assess
the likely effect climate variability and change will have on Ghana’s energy security since
many projections for the country point to a warmer dry future. This study used regression
analysis, F-test and t-test to analyze the influence of rainfall, ENSO, lake level elevation
and net lake inflow on power generation at the Akosombo Hydroelectric power station
from 1970 to 2010. The study found that ENSO explained 19.5% of the variability in
rainfall inputs into the lower Volta Basin where Ghana’s hydropower projects are found.
Rainfall variability accounted for 21.2% of the year to year fluctuations in power
generation from the Akosombo Hydroelectric power station between 1970 and 1991.
Additionally, ENSO and lake water level accounted for 72.4% of the interannual
fluctuations in power output between 1991 and 2010. The occurrence of an El Niño episode
was found to reduce Akosombo power output by 1169.64GWh per year. The study
therefore concludes that the country should diversify its power needs away from
hydropower in order to attain energy security for current and future generations.
