Using PV to meet Peak Summer Electricity Loads

Abstract

Until the last decade, peak electricity loads in Australia were mostly in winter. In many States peaks are now in summer and are growing rapidly, with one of the main contributing factors being the increase in use of air conditioning. South Australia has the “peakiest” load pattern. The ratio of average to peak load in South Australia has fallen from around 60% to 50% over the past few decades, resulting in increasingly inefficient use of costly transmission and distribution assets. In a recently monitored new subdivision in Adelaide, 50% of the distribution feeder maximum load was only exceeded for 5% of the year. This trend is evident in other areas with high housing growth rates such as Western Sydney, where 10% of the system capacity is used for only 24 hours a year. At the same time, spot prices in the National Electricity Market during major summer peaks can be very high with associated cost implications for electricity retailers and hence for customers. AGL South Australia has introduced a summer tariff, which currently is set at 20.944 c/kWh for day rate consumption above 3.3 kWh/day, 10% higher than the standard tariff. This paper will examine the potential for PV to contribute to peak summer loads in a number of locations with different load characteristics. It will also examine the implications of temperature and orientation on PV performance at peak times. The results will be used to analyse the value of PV to electricity network operators and retailers in managing their summer peak load problems in future years.