TMY versus multi-year time series of meteorological conditions for the characterization of central Poland's suitability for photovoltaics

In this paper, the region of central Poland is assessed in terms of its suitability for the development of one of the branches of solar energy – photovoltaics. The evaluation is made using multi-criteria analysis method in which meteorological variables are taken as assessment criteria. A suitability index is constructed and its spatial distribution is computed on the basis of typical meteorological year data set (TMY approach) and measured data set from the period 1971–2000 (multi-year approach). The differences in central Poland’s suitability for the use of solar energy when calculated using these two different data sets are assessed. Despite using the same (or equivalent) criteria and their weights, the distribution of suitability index values in the two approaches is different. The biggest differences between the values obtained in TMY approach and multi-year approach are found in Warsaw – they exceed 9%. On the significance level α = 0.05, the differences between the TMY approach values and multi-year approach values are statistically significant, meaning that it cannot be concluded that these data sets can be used alternatively.