## 3 Results
### Feasibility Assessment
Many other examples of calculation can be constructed. If the irrigated area is increased or more population needs to be supplied with water, this would imply increased water requirements, more solar panels needed, a more powerful pump (kW) to satisfy the delivery of required flows as well as more kWh consumed. This scenario could be financially more viable because the gross farm profit would increase; on the other hand, it would increase the risk of groundwater over-abstraction and jeopardize the geophysical feasibility. The Finance Deployment Tool was used to identify possible financial mechanisms for the operation and maintenance of solar-powered groundwater pumping systems. For the specific study sites, the users are not expected to have collateral assets, soft collateral or other guarantees for loans, alternative sources of income, established value chains or cooperative programs, and they do not possess initial capital. However, the users have bank accounts, mobile devices, they are able to pay commercial interest rates and they live in communities with common goals and reciprocal trust. They may be willing to use solar-powered pumps without buying them, pay monthly fees into a common trust and depend on other users according to an agreed schedule. Specifically, agricultural water users require a regular supply of water for irrigation and livestock, they are subsidized by government and there is interest from the private sector to purchase their products. After exclusion of unfeasible financial mechanisms, the following options are available: leasing, cooperatives, informal saving groups and pay-per-use. These are feasible financial mechanisms for the operation and maintenance of solar-powered groundwater pumping schemes through MUS. Based on the information collected above, the design and sizing of solar-powered groundwater pumping schemes were carried out for each individual case study site (Table 1) with the Pump Sizing Tool of SPIS [50]. It was assumed that an average of 6 sun hours per day occur at an average solar irradiation of 4.9 kWh/m\({}^{2}\)/d calculated from the weather data measurements at Givari weather station. A default solar system power loss of 25% was assumed with a fixed (non-tracking) solar panel array. Borehole yields in the fractured rock system are very variable; however, a realistic figure for borehole yields is 2 L/s as reported in previous studies [53; 62]. The estimated water source yield was therefore 173 m\({}^{3}\)/d (2 L/s) with 50% sustainable extraction rates. Required daily water pumping rates corresponded to peak monthly water requirements calculated for each farm and village. Farms usually use 40 mm (1.5 inch) conveyance pipes and communities 60 mm (2.4 inch) pipes for drinking water, with a variable pipe length and fittings determined for each specific site. Table 1 summarizes water requirements, required total dynamic head, pipeline length and diameter for each study site. The Pump Sizing Tool calculated the peak power requirement (kWp) and the required solar panel surface. Required valves and fittings were also entered in the program to calculate pressure losses based on realistic piping system configurations. Each study site has different characteristics in terms of water requirements and pressure heads to be delivered by the pump depending on the geophysical settings. Water requirements depend largely on the size of the population to be supplied with water, ranging from 28.8 m\({}^{3}\)/d for Mizilea to 58.9 m\({}^{3}\)/d for Nhlambeto farm in Dzumeri (mixed water use). Water requirements on farms, assuming the same cropping system and irrigation area as the hypothetical farm, are the same (33.9 m\({}^{3}\)/d) because the same climatic data were used.