kW-value of a photovoltaic power generation system evaluated from actual data on electricity demand and insolation

摘要

This paper proposes a new method of evaluating the kW-value of photovoltaic power generation systems (PV systems). This evaluation is based on actual insolation data, collected by the Japan Meteorological Agency at four locations in the Chubu area in Japan, and the actual electrical load data of the Chubu area in the 1990s. We selected specific days on which the daily peak load was relatively high. For the selected days, we estimated the average output of PV systems using the IEA's method for considering the temperature dependency of cell efficiency. Then, we calculated the reduction of the peak load ΔL{sub}p(d). The resultant ΔL{sub}p(d) was distributed in the range from 0.4 to 0.5 kW/kWp. We evaluated the average value of the smallest ΔL{sub}p(d) as the kW-value of PV systems. When the kW-value was evaluated for the two or three days with the smallest ΔL{sub}p(d) among the selected 10 days for 1 year, the kW-value of the PV systems was calculated to be about 30%. This was close to the value obtained by the conventional loss of load probability (LOLP) method. Our study evaluates the relationship between the kW-value of PV systems and the number of days on which the insolation was low but the daily peak demand was relatively high.