Influence of different photovoltaic cooling strategies on its average monthly performance

Nowadays, in order to reduce climate-altering emissions due to air conditioning and mechanical ventilation of internal environments, it is crucial to encourage the use of renewable source production plants. The most mature technology is certainly the photovoltaic one. However, this has limitations due to its poor efficiency and its reduction at high temperatures. In order to increase the efficiency of these systems, different system solutions have been proposed over the years and a great effort has been invested in the research of new materials. Some of the most promising solutions are configurations with panel cooling by means of external fluids. This can happen in a forced or natural way and the removed heat can often be reused in other processes. However, being a very recent technology, it is not easy to determine its suitability in a given application at an early stage. There are no clear and simple methodologies which allow to evaluate the increase in performance obtainable thanks to the adoption of panel cooling. The purpose of this research work is precisely to present an innovative methodology that, exploiting the measurements collected over many years, allows to determine the performance of the panel at a daily-monthly level, as the cooling methodology varies. In particular, corrective parameters are proposed which modify the already known Siegel method, widely used to determine the daily monthly mean efficiency of uncooled panels. In the work, it is also highlighted how the input values of the model, taken from the UNI standard, do not fully reflect reality. This may suggest the need for a regulatory update. The increase of the photovoltaic efficiency would allow the reduction of the surface needed in a building for the local electricity production. This electric energy can be used to power different loads such as the ventilation system and the HVAC.