## 4 Discussion
From the geotechnical feasibility perspective, the area is moderately suitable for the utilization of solar energy with average solar irradiation of 4.9 kWh/m\({}^{2}\)/d (photovoltaic power output of 1589.3 kWh/kWp) and a large number of sunshine hours per day. There is potential for intensive agricultural production and value-added products with access to both informal and formal markets in the urban areas of Giyani (-50 km north) and Tzaneen (-70 km south-west). Other economic development activities could relate to spin-off businesses. Because of the current lack of bulk water supply, MUS systems would definitely benefit livelihoods and cultural activities, and improve sanitation, hygiene and health. Although formal waste collection sites do not exist in the area, including e-waste, batteries, plastics, etc., the volume of waste generated by the solar-powered pump systems is sufficiently small to be stored at localized sites and it does not represent a problem. The implementation of solar-powered groundwater pumping systems may result in beneficial impacts on water security, agricultural impact, involvement of local communities and gender equity. However, it may have negative impacts on natural resources, especially if over-abstraction of groundwater occurs, which needs to be controlled through sustainable management of groundwater. Groundwater storage should be sufficient to sustain water supply during periods of drought as a reserve, however groundwater recharge will be essential from occasional flood events to render abstraction sustainable. Shallow groundwater yields are moderately high in the area, however one of the main constraints is the long-term sustainability of groundwater abstraction and the risk of over-exploitation of groundwater resources. In previous research conducted by [62], it was estimated that a 100 m reach of the dry Molototsi River stores 2700 m\({}^{3}\) of water in the sand banks. This is sufficient to irrigate \(\sim\)0.66 ha of vegetables for one season, assuming irrigation water requirements of 4000 m\({}^{3}\)-ha\({}^{-1}\). A monitoring system needs to be put in place in order to keep track of groundwater levels as well as groundwater quality through a physical,chemical and microbiological monitoring program. Technical capacity for community monitoring needs to be built. The financial viability of solar energy was demonstrated by comparison with traditional energy sources in the case study examples. While solar energy can provide cost savings of \(>\)ZAR 400,000 compared to grid electricity over a life cycle of 25 years, diesel-powered systems are not financially viable. The constraint is the high capital costs of solar energy. It is therefore likely that the capital investment will have to be subsidized by rollouts by the government or donors. The operation and maintenance of the water supply scheme according to the MUS principles should be handed over to the community under the guardianship of the water services provider (local authority). The participation and buy-in of the community and local government is therefore fundamental as these entities will be co-owners of the systems and be responsible for the operation and maintenance in the long run. Feasible financial mechanisms for the operation and maintenance were identified to be leasing, cooperatives, informal saving groups and pay-per-use. A full review of financial models and operating options is pertinent in this regard. The sizing of the system is very site-specific, and this was designed with the SPIS tool [50] based on biophysical information, specific borehole yields and aquifer characteristics, required pressure heads and water requirements. It is in the same order of magnitude as sizes and designs that were found in the literature [17]. Peak power requirements and the design of solar panel arrays can be further adjusted based on the equipment specifications and availability on the market from suppliers and manufacturers as well as photovoltaic arrays arrangements.