ECOMOMIC ANALYSIS OF HYBRID PHOTOVOLTAIC/THERMAL SOLAR SYSTEMS AND COMPARISON WITH STANDARD PV MODULES

ABSTRACT: Most of the absorbed solar radiation by solar cells is not converted into electricity it increases their temperature, reducing their electrical efficiency. The PV temperature can be lowered by heat extraction with a proper natural or forced fluid circulation. An interesting alternative to plain PV modules is to use Hybrid Photovoltaic/Thermal (PV/T) systems, which consist of PV modules coupled to heat extraction devices, providing electricity and heat simultaneously. Hybrid PV/T systems are of higher cost than standard PV modules because of the addition of the thermal unit and therefore a cost/benefit analysis is needed to find out the limits of practical use of these. A couple of typical applications are selected in order to assess the benefits for the users of hybrid PV/T systems comparing the payback time with PV systems and Solar thermal ones, under the current support schemes and conditions in Greece. A spreadsheet was developed that calculates on an hourly basis the annual energy output of the different systems. Furthermore, the energy output and the estimated system costs per surface area are introduced in an economic analysis spreadsheet, where the payback time for each system is calculated