Aleltu Hydroelectric Project Summary
Project Overview
The Aleltu Hydroelectric Project is a major development in Ethiopia located 80km north of Addis Ababa, identified as economically attractive in the 1982 Power Planning Study. The reconnaissance and prefeasibility studies (1983-1984) evaluated its technical and economic viability.
Key Project Data
- Ultimate Potential: 1,020 MW capacity, 3,592 GWh/year energy
- First Stage (Tiliku Aleltu + Jida): 300 MW capacity, 1,040 GWh/year
- Head: 1,070m maximum gross head
- Drainage Area: 4,230 km² (12 sub-basins)
Project Components
| Component | Tiliku Aleltu | Jida | Combined |
|---|---|---|---|
| Dam Type | Earth-and rock-fill | Earth-and rock-fill | - |
| Reservoir Volume (Mm³) | 92 | 1,050 | 1,142 |
| Spillway Type | Uncontrolled weir | Uncontrolled emergency weir | - |
| Interconnection Tunnel | 6km unlined tunnel between reservoirs | ||
Key Findings
Reconnaissance Study (1983)
- Identified 14 sub-basins with development potential
- Recommended Tiliku Aleltu (Stage IA) and Jida (Stage IB) as first phase
- Determined powerhouse should be at Location A in Zega Wedem Gorge
- Calculated incremental energy cost of 22.1-30.2 mills/kWh (below grid supply cost)
Prefeasibility Study (1984)
- Confirmed technical feasibility of first stage
- Established detailed project parameters:
- FSL: 2,598.4m for both reservoirs
- Power tunnel: 3.2m diameter, 16.3km length
- Penstock: 2.4m diameter, 2.1km length
- Recommended proceeding to feasibility study
Recommendations
- Proceed with full feasibility study
- Install additional streamflow/rainfall stations
- Ensure continuous monitoring at existing stations
- Obtain 1:50,000-scale mapping of entire project area
Economic Analysis
The project compares favorably with alternatives like the Gilgel Gibe project, with energy costs below the long-term grid supply cost of 35 mills/kWh. The first stage development shows a benefit-cost ratio of 1.37-1.45.