Angelo Bernasconi

Energy rating of PV modules: comparison of methods and approach

The Matrix and Performance Surface Methods of Energy Rating are related techniques under development for the determination of electrical yield that is intended to be a more useful predictor of performance for installers than Wp alone. Here a power matrix or performance surface as a function of irradiance and ambient temperature P(Gi; Ta) is linked to a climatic condition occurrence matrix N(Gi, Ta) for a particular location. The use of just two independent variables has the advantage of simplicity but it is important to evaluate the possible cost of reduced accuracy due to the exclusion of other variable parameters such as Air Mass for example. The power matrix may be determined by outdoor or indoor measurements, and the complete matrix may also be extrapolated from a reduced data set using models of cell behaviour thereby reducing measurement time. The present paper relates solely to crystalline Si and reports on the comparison of outdoor measurements at two sites, and their further comparison with indoor measurements.

Thermal Isolated BIPV Design Matched to A-Si Modules Behaviours

In BIPV design with c-Si cells, ventilation is important in order to keep cells as cool as possible. To allow a good ventilation it is therefore generally preferred to mount the modules separated from the existing roof. In the case of sloped roofs the modules are superimposed to the existing roof and for flat roofs separated tilted mounting structures with wind loads are used instead, but both are no real building integrations. In this paper we analyse the behaviour and the energy yield of a 15.36 kWp PV system based on flexible triple-junction thin-film amorphous silicon modules laminated together with a single ply roofing system based on a flexible polyolefine (FPO) membrane which acts as a waterproofing system. Compared to c-Si modules, a thermal isolated BIPV design matches the best the thermal behaviour of a-Si technologies