Energy-economic Optimization of Flat-plate Collector

The optimization of solar collector design may be based on energy, economic or energy-economic criteria. Obtaining maximum energy from a given collector area or determining the required minimum area of collector that produces a given amount of energy are examples of energy criteria. Designing a solar collector with a minimum cost is an example of economic criteria. The net present values, internal rate of return and payback period methods are examples of energy-economic criteria. This paper deals with the obtaining collector design parameters that provide the highest net present value. The following design parameters have been accepted as the decision variables: air gap size between the absorber and the cover glazing, emissivity of the absorber, frame insulation thickness, and distance between riser pipes. A detailed analysis is carried out for evaluating the thermal and optical performance, energy flows and losses for typical flat plate solar collector under given operating conditions producing hot water for household needs. The high-quality flat-plate solar collector was chosen as a reference alternative. The results of modeling indicate that NPV value of solar collector variant with reduced to 50 mm distance between riser pipes is higher than in the reference variant, which indicates that a design change is economically justified.