SHORT COMMUNICATION: Does climate change affect the design of stand-alone PV systems?

Abstract

This paper investigates the effect of using sequences of past daily solar radiation data on PV system sizing for the case of Efford (UK). For a given system configuration that never sheds load, the lowest SOC reached by the battery is found by an energy balance model, and the energy deficit calculated for a given climatic cycle. Although the average irradiation changes little during the years 1958-1994, there is a substantial increase in the storage requirement, which seems to be related with an increase in the persistence of low solar radiation values.

Stand-alone PV system design: Results using a new sizing approach

“…We consider a basic configuration of a stand-alone system with constant load [1]. Firstly, we construct the sizing curves for three locations-London weather station (UK), Salzburg airport (Austria), and Heraklion (Greece)-based on 10 years of historical daily solar radiation data.…”

“…By using a standard model based on daily energy balance, configurations can be determined defining a system 100% reliable over the period of time when the data are available [1,2].…”

“…The PV generator of the system is assumed to be orientated so that the energy yield during the winter months is maximized and the minimum generator size is determined from the daily energy balance [1,2]. To supply a given constant daily load, an array with at least equal daily energy output is needed.…”

“…A model based on daily energy balance [1] was used to find the battery state of charge (SOC). The input is 10 years (1981-1990) of daily solar radiation data on the horizontal plane for each of the three locations.…”

“…A new method has been suggested recently where supply reliability is defined in terms of the length of time that the system supplies load without interruption [1,2]. This requirement allows for the present investigation.…”