Site suitability for photovoltaic farms and current investment in Romania

Abstract

In recent decades, development in the field of solar energy has been a growing challenge in the context of the transition from conventional to renewable energy sources. However, there are cases where investments in photovoltaic farms do not reach the maximum potential of a territory for their emplacement. Therefore, the present study aims to analyse the site suitability for photovoltaic farms in Romania in relation to current investments in the field. The suitability map was obtained through a simple heuristic approach, based on the Multicriteria Evaluation of favourable/restrictive biophysical and anthropogenic data, integrated in the GIS-Weighted Overlay spatial analysis. The results were compared to the current distribution of photovoltaic farms, quantified by the visual interpretation of high-resolution images provided by Google Earth. Overall, the suitability map obtained shows a relatively high potential for the location and expansion of photovoltaic farms in the area, the very high and high suitability classes summing more than 7,000,000 ha (29.9% of the country's area). The highest potential has been obtained for the southern and south-eastern part of Romania, where the zonal calculated mean suitability scores highlighted the Bucharest-Ilfov (4.94), South-West Oltenia (4.64), South-Muntenia (4.63) and Southeast (4.42) development regions (NUTS II). However, analysing the frequency of existing photovoltaic farms, the study indicates a potential for solar energy not yet sufficiently exploited, but also possibly inappropriate between the degree of suitability and the photovoltaic farms implemented so far. Hence, the comparison of calculated mean suitability scores and the percentage of the total area allocated for existing photovoltaic farms indicates several mismatches between the investments made in the area and the modelled site suitability, mainly in the Ilfov, Tulcea, Constanța, Buzău, Satu-Mare, Brașov, Prahova and Galați counties. At the same time, the results reveal an alternate possibility of using/reusing degraded or contaminated land, through investments in the solar energy, several aspects being highlighted for the ceased mining areas, landfills near urban centres, or poorly productive agricultural lands. This study can provide important information to decision makers and potential investors, in order to streamline future projects by setting up photovoltaic farms in accordance with the modelled suitability classes.