This thesis has focused on the strategies that can be implemented by electricity utilities and private investors in increasing the penetration of rooftop photovoltaic systems (RPVs). Even though the proposals are general and applicable for any locality, the key studies of this research have been focused on the Australian electricity market.
First, a detailed review and comparison of all Australian power distribution companies has been carried out in terms of the percentage of the supplied customers and the customer density per kilometre length of their power lines. Following that, the daily electricity supply and the electricity unit charges offered by the active electricity retail companies in the zones of each of these power distribution companies are reviewed and compared. Based on this information, the annual electricity bill of a customer supplied by different power distribution companies and retailers is calculated. Through this study, the national average annual electricity bill has been determined for Australia and the power distribution companies are categorised under four segments of very cheap, cheap, expensive, and very expensive companies. This study has highlighted some of the key challenges faced by power distribution companies in Australia in supplying power through a more localised renewable based generation.
Installing an RPV by a household is a big decision, and there are many factors which need to be considered before this decision. It can be highly rewarding in some cases and for others, it may bring a loss in the investment. The main factors which need to be considered are the electricity consumption tariff, electricity consumption pattern, the location of the household and the tariffs offered by the utility in that area. In this thesis, economic incentives of installing a RPV and battery energy storage (BES) are discussed for a household in different states, served by various utilities. A comparison is made to find which states are more suitable in terms of gaining financial benefits from RPVs.
A flat rate feed-in tariff is an incentive offered by many utilities to encourage their customers to invest in electricity generation from RPVs. Such a scheme is usually designed by financial techniques that mostly consider the initial capital cost and electricity spot price. However, such an incentive cannot help the utilities to address the technical challenges in networks with large renewable penetration. In this thesis, a dynamic feed-in tariff has been proposed and designed based on the value of electricity, hosting capacity, ambient temperature and time of day. This feed-in tariff will specifically support utilities that experience challenges in the electrification of remote areas or observe excessive stress on their networks at demand peak periods. The proposed feed-in tariff encourages the rural customers to install RPVs while discouraging the urban customers from installing RPVs without BES.
Solar leasing is another opportunity to enhance the rapid uptake of RPVs. Even though solar leasing has attracted widespread acceptance in some countries, it has not been successful in being popular in some other places mainly due to lack of awareness of the model and economic viability in relation to outright buying a RPVs. One of the solar leasing models is roof rental in which a company leases the roof of residential premises for installing RPVs and selling the generated electricity to the utility. This thesis has explored an economically viable alternative for roof rental from the perspective of the engaged leasing company. To this end, an economic analysis has been performed to determine the net present value from the roof rental payments and versus different ratings of RPVs, desired interest rate and existing feed-in tariff.
Furthermore, a BES can play an important role in realising maximum benefit from RPVs. However, the cost of a BES is comparatively high, and the BES of individual households may not be optimally utilised during a significant portion of the year as there may not be enough generation from RPVs during winter to charge the BES to its full capacity. Community solar on the other hand, if optimally designed, can give the opportunity to use a BES to its maximum capacity. Such systems can benefit many of the remote and rural communities, that are usually supplied by diesel generators, or long traditional distribution lines, which in addition to being expensive often don’t provide the reliability at desired level. These systems can also benefit most of the urban areas since the unmanaged penetration of RPVs has resulted in the undesired duck curve profile in the network. To this end, this thesis has proposed and validated the appropriate design criteria for community solar projects with an aim to improve the network duck curve profile, enable peak-shaving and increase the self-sufficiency of the community
