Potential for small hydropower development in the Lower Pra River Basin, Ghana

Abstract Study region : Lower Pra River (LPR) Basin, Ghana Study focus : This study examines the potential for Small Hydropower Development in a semi-arid environment albeit the lack of data. Geographic and site specific information acquired through geographic and remote sensing techniques are applied in a physically based semi-distributed hydrologic model to simulate discharges for ungauge areas for consideration of hydropower. Flow Duration Curves (FDC) and Power Duration Curves (PDC) have been constructed for suitable sites from which design flow and firm energy is established. New hydrological insights for the region : The final assessment resulted in the identification of ten sites (HP1 – HP10) along the LPR with potential for hydropower generation. The maximum and minimum mean annual flows were 172.9 m3/s and 5.3 m3/s at hydropower sites HP1 and HP2 respectively. HP1 demonstrated the highest hydropower potential with firm power and annual firm energy at 90 % dependability estimated as 12.22 MW and 77.10 GW h with a total annual energy production (AEP) of 183.77 GW h. Hydropower sites HP3 and HP7 also had relatively high hydropower potential with firm power and annual firm energy of 10.0 MW, 47.01 GW h and 9.0 MW, 40.77 GW h respectively with AEP expected to be in the order of 157.67 GW h and 141.91 GW h respectively. A cascade system is proposed for hydropower sites HP1, HP3 and HP7 with estimated combined AEP of 483.4 GW h.