Financial and environmental analysis of rooftop photovoltaic installations with battery storage in Australia.

Recent trends in increased public environmental awareness coupled with the introduction of governmental incentives, has resulted in a remarkably rapid growth in rooftop photovoltaic (PV) installations at a residential level in Australia. Despite the widely perceived economic and environmental benefits of rooftop PV, the economic and environmental performance of rooftop PV under Australian conditions are yet to be thoroughly examined. Whilst prior studies on the subject of rooftop PV are extensively overseas based, the conditions under which they are performed differ immensely from the Australian conditions. Consequently, this paper focuses on evaluating the life cycle economic and environmental merit of rooftop PV in Australia. By making use of component-wise costs and embedded emissions associated with each component of the rooftop PV generation system, the life cycle cost and emission models have been developed. For this to occur, the Australian costs and, energy and emission intensities have been used. All the life cycle factors relating to the manufacturing, purchasing, installation and operation of rooftop PV are considered. A sensitivity analysis is performed with respect to electricity price, feed-in tariff, battery price, battery lifetime and emission intensities. The results of the cost and emissions analyses are collectively used to estimate the cost of emissions mitigation through the use of rooftop PV for current and potential future scenarios in Australia. The cost payback and the energy payback times are found to range between 11 to more than 25 years and 1.75 to 14 years, respectively. The study also reveals that local load profile can have a significant impact on payback times. For example, the cost payback without battery storage is found to be the least for Tasmania which hosts the least favourable solar insolation conditions and lowest feed-in tariff amongst the Australian states however possesses a high daily load and electricity price. [ABSTRACT FROM AUTHOR]