Nowadays energy and water are some of the most important issues facing mining industry. Many mines are located in desert areas and they need to pump water from isolated wells or from the ocean. To satisfy the water demand many high power water pump stations are required. The operation of these systems is expensive due to the high-energy cost. This paper presents a case of study of a solar system to assist the operation of a water pump station of a mineral operation in Chile. An economical analysis is carried out with respect to different design variables and the percentage of the total power required for operating the system in the less favorable conditions (degree of assistance). It demonstrates that the maximum net present value is obtained for the maximum assistance, i.e. supplying the full energy in the less favorable conditions. However, the internal rate of return will be maximized at the point where the system only supplies the energy to satisfy the full demand at the most favorable conditions. Finally the study shows that from an economical point of view PV technology is an attractive alternative to support the mining operation at present time.