Cost per kWh produced and payback time of a PV -solar -thermal -combined roof top collector at different locations in New Zealand

Abstract

[Abstract]: This study presents an economic evaluation of three types of solar applications: a) grid-connected photovoltaic system, b) grid-connected photovoltaic system combined with a solar water heating system and c) solar water heating system only. The operational data of an 1.3m2/120-litre tank evacuated tube solar thermal collector and the data of an average1kWp grid-connected crystalline photovoltaic solar generator are taken as a basis for the calculation. The annual amount of energy produced, the incurred cost and the resulting savings over the system lifetime are used to determine the cost per kWh and the payback time of the system at different geographic locations in New Zealand.. The analysis presented in this paper for a combined solar installation including a grid-connected photovoltaic system and a solar thermal unit at a typical domestic house has shown that such a system will present realizable benefits compared to simple grid-connected photovoltaic systems operated separately. The calculations demonstrate the shortest payback time and the lowest cost per kWh for the pure solar water heating system compared to the two other alternatives, the combined system and the sole GC-PV.