Project Overview
The Bumbuna I hydroelectric plant (50 MW) is located on the Seli river in Tonkolili district, Sierra Leone. Owned and operated by public sector EGTC, it has operated since 2009 with average output of 222.5 GWh (51% capacity factor). The Millennium Challenge Corporation feasibility study (2023) confirms that expanding by a further 60 MW is the lowest cost option for increasing energy provision. The expansion requires minimal new civil works because the offtake, intake, power tunnel, screens, and main inlet valve are already designed for additional 80 m³/s flow (60 MW). Options: single 60 MW turbine or 2×30 MW turbines. Government seeks a transaction combining privatisation of the existing 50 MW plant with an agreement for the new owner to finance and build the expansion, underpinned by a PPA with the Electricity Distribution and Supply Authority and appropriate guarantees.
Quick Summary
Expansion of existing 50 MW Bumbuna I hydro plant by 60 MW (371 GWh additional output). Lowest-cost generation option for Sierra Leone. No resettlement, low environmental impact. Public-private transaction combining existing plant privatisation with expansion financing.
Target Market
National – Sierra Leone (serving Electricity Distribution and Supply Authority under PPA)
Sub-Sector
Hydropower / Renewable Energy Generation
Market Analysis
Sierra Leone faces chronic energy deficits. The 50 MW Bumbuna I is the lowest-cost generator in the national system. Adding 60 MW (371 GWh/year) represents a substantial increase in affordable, renewable baseload capacity. The expansion benefits from existing infrastructure (dam, tunnels, 200 km 161 kV transmission line to Freetown). No resettlement costs. Expected low environmental impacts with mitigation. The transaction structure (privatisation + expansion agreement) aligns investor returns with national development priorities.
Project Details
Project Information
Location Details
Ideal Investor Profile
Independent power producer (IPP) or energy infrastructure investor with experience in hydropower projects, preferably in Sub-Saharan Africa. Capable of financing US$60–67 million expansion and undertaking privatisation of existing 50 MW public asset.
Technical Requirements
Experience with Francis turbines, run-of-river hydro plants, and powerhouse extension construction adjacent to operating facilities requiring specialist blasting to avoid damaging instrumentation.
Financial Information
Payback Period
To be determined based on PPA tariff structure
Investment Incentives & Support
Location Information
Project Location
Country: Sierra Leone
Specific Location: Bumbuna, Tonkolili District, Northern Province, Sierra Leone
Location Advantages
- Strategic location in West Africa
- Access to Sierra Leone market
- ECOWAS regional market access
Risk Assessment & FAQ
Risk Factors & Mitigation
Risk Factors
- Construction adjacent to operating powerhouse requiring specialist blasting
- Hydrological variability (inflow data 2009–2022 shows fluctuations)
- Sovereign/offtaker payment risk
- Chimpanzee population impact
- Dam stability concerns
Mitigation Measures
- Detailed engineering and blasting protocols to avoid damaging existing instrumentation
- Run-of-river design; historical performance average 51% capacity factor
- PPA supported by appropriate Government of Sierra Leone guarantees
- Mitigation measures already identified; expected low to no detrimental effect
- Powerhouse extensions founded in hard rock; no compromise to dam integrity confirmed
