IED is an independent consulting and engineering firm involved in the provision of sustainable energy services since its creation in 1988. The involvement of IED extends from the study phase right through to the construction and commissioning of infrastructure such as distribution networks and renewable energy production plants.
Rural settlements in Mauritania lie in a very rough environment characterised by a warm and dry climate, poor access, low income and low power demand. Most dwellings are scattered in desert areas and very few localities are electrified, generally with costly and unreliable diesel gensets and mini-grids. With the fixed regulated tariff (0.27 €/kWh), the private operators can only operate with a high subsidy level from the Government to cover operating costs. The lack of professional maintenance skills is another constraint for sustainable and affordable power supply.
There are a few hundred rural centres with sufficient power demand to benefit from stand-alone mini-grids, supplied with as much solar as possible. Solar hybrid generating systems combined with LV/MV mini-grids are seen as the most suitable solution for those populations, allowing more reliable and affordable electricity for domestic and non-domestic demand. Wind power is a relevant alternative for several spot areas.
The IPES-SOLAR project is electrifying six isolated localities with solar/diesel supplied mini-grids ranging from 16 to 50 kWp. One of these localities is the village Ain Ehel Taya (Adrar) which was previously equipped with a mini-grid supplied by a 55 kVA diesel generators for 250 customers (mainly households). The diesel share of operating costs was about 0.35 €/kWh and the operator received a subsidy of 0.25 €/kWh, making this business hardly sustainable when considering the low load factor and the high maintenance and replacement costs.
The hybridised system includes a 17.6 kWp solar PV array, 165 kWh 48 V battery, 6 x 7 kVA Studer inverters and the 55 kVA diesel genset. “Private Delegates” (appointed by state implementing agencies) are trained to optimise the operations (fuel saving and loss reduction), to maintain the generation and distribution system and to efficiently manage their customers (through support tools). Post-project measures include periodic technical and commercial trainings for operators and information to customers.
The total investment costs for hybrid generation systems (8-11 €/Wp) and for distribution systems (15k €/km of low voltage lines) are pretty high due to the low attractiveness for bidders (i.e. political instabilities) and to the hard environment for delivery and installation. The whole project is co-financed by the EU Energy Facility (73.81%) and the Mauritanian government (24.09%). Local beneficiaries’ contribution is about 2% through the monthly tariff and connection fees. The funding of the project allows an expected 58% reduction on kWh cost and 8,000 € subsidy savings per year for the Ain Ehel Taya site. For the system to be sustainable in the long run, new concessional funding will need to be found for battery replacement.
This EU project counts as a pioneer for solar hybrid systems in Mauritania. The potential for replication of this technology solution is high with more than 300 identified centres, most non-electrified and few electrified with diesel gensets. Several donors have shown interest in supporting larger programmes using hybrid systems. A first lesson learnt is the need for a mitigation system for coping with high load spikes that occur when starting cereal mills. Further lessons learnt from this project are awaited, in particular how far government (fuel) subsidies can be actually reduced, how operators can develop safe businesses, and how variable and growing demand can be handled.