PV-Diesel Hybrid Mini-Grid
Up to now overall experiences with PV-Diesel Hybrid Mini Grids are not very positive. The established tariffs are often too low to cover the costs. The capacity of the system is often too low, leading to frequent overloading. Due to insufficient tariffs financial reserves for investment cannot be built up.
Electricity from PV-Diesel system generally costs around 0,5-0,8 Euro per KWh. Costs of Diesel generators alone are calculated to be around 0,35 Euro. The high costs of the hybrid system are mainly caused by the storage of the solar electricity (around 0,3 € per KWh).
One possibility to avoid high storage costs is to use the solar electricity only during daytime, with a small battery system for peak demands. At night or during rainy days the electricity is generated by the Diesel generator.
In Senegal EnDev disseminates PV-diesel hybrid mini-grids for the electrification of villages with up to 500 inhabitants or 40 households.
The systems consist of (approximate total cost including installation in brackets):
- a PV array with a capacity of 5.1 kWpconsisting of 30 polycrystalline PV modules with a capacity of 170 Wpeach (15,000 €)
- a battery bank consisting of 24 elements of 2 V of lead-acid tubular plate batteries; element capacity is 800 Ah C10 leading to a bank capacity of 38,4 kWh (15,000 €)
- a monophase generator of 10 kVA linked to the PV system (7000 €)
- a 5000 VA inverter (4,000 €)
- 220 Volts low voltage three phase AC distribution through a mini-grid (10,000 € per km; 2-3 km per village)
- system housing (6,000 €).
The total costs of installing a system is between about 70,000 € and 80,000 €.
The 16 systems have a total PV capacity of 81.6 kWp and can generate 106.9 MWh per year. Electricity generation by the diesel generator is not included in this calculation.
