Economic feasibility of solar pumping

Abstract Two major questions concerning the economic feasibility of solar pumping are addressed. The first of these is concerned with finding a least-cost solar system by considering the alternative use of either thermal or water storage. The second involves the determination of areas where solar energy would be economically competitive with electricity or fuel as a power source for pumping installations. A linear programming solution is developed to find the optimal combination of thermal and water storage for a solar installation. The formulation is then extended to determine a least-cost system when hybrid systems are considered. A hybrid system may incorporate a combination of solar, electric and fuel power inputs. The concept of a breakeven “critical” distance from existing infastructure for solar installations is developed, and an example problem is provided to illustrate typical values of this distance and to show its sensitivity to the base energy costs and rate of inflation for those costs. It appears that electrical pumping is probably the most economical alternative provided that electric infrastructure is located nearby. Fuel power will also be more economical than solar if there is a source of fuel near the proposed pumping site. However, solar systems may be economically competitive when considered for installation at realistic distances from existing infrastructure.