Meteorological input data effect on sizing stand-alone photovoltaic systems

摘要： The exploitation of Renewable Energy Sources (RES) has already been proved as a promising power source for a sustainable future in energy supply, to cover the world’s energy demand. Solar energy is considered the most abundant RES of all, while being available in every part of our planet makes it favorable for distributed RES energy production systems. Solar-based stand-alone power systems, installed in remote areas far from the main local electricity networks, can be cost efficient and even provide energy security given that they have been carefully sized. Moreover, stand-alone photovoltaic systems can highly contribute to distributed renewable energy and microgrid networks even without other RES combination if they integrate with an appropriate energy storage (ES) system. During the sizing procedure of a photovoltaic (PV) plant, the solar potential of the area is the dominant parameter. The use of solar energy values, which may deviate from the actual values, has a relatively small impact on the overall energy assessment of interconnected photovoltaic installations. However, in the case of stand-alone PV systems, where the user requires energy autonomy, it is necessary to use hourly solar radiation along with air temperature values with increased reliability in order to determine the most cost effective combination of PV-ES system. Although there is an extended literature on stand-alone PV systems sizing procedures, the effect of using different input meteorological data on system’s size has not been sufficiently addressed. In this context, the present study examines the use of different meteorological input data of solar radiation and air temperature with data series from 12 individual years, a Mean Year (MY) and a Typical Meteorological Year (TMY). Although the TMY has been mainly used in building’s energy calculations, the results of the present work prove that the use of a TMY increases the power system reliability if compared with sizing the system by using time series of individual years or a MY. The case study presented in the specific work concerns an application of combined PV-ES able to provide energy autonomy to a domestic consumer, in a remote area in the island of Rhodes.