Modelling impact of PV battery systems on energy consumption and bill savings of Australian houses under alternative tariff structures

This study assessed the impact of (Photo-Voltaic) PV battery systems on peak demand and energy consumption, and thus bill savings across households under two existing and nine potential electricity tariffs. Using case studies of old and new houses, we found an installation of 5.5 kW PV reduced the peak demand of the old houses from the grid by 16.5%, 14.9% and 10.9% respectively in Townsville, Sydney and Melbourne, Australia respectively. The corresponding decreased in its annual electricity consumption from the grid were 84%, 82% and 163%. The peak demand reduction of the new houses were less than that of the old houses, whilst the annual electricity consumption reductions were larger. Adding 16 kWh battery storage more than doubled the peak demand reduction in Townsville and Melbourne. We also found that, with PV alone, households on tariff of flat rate retail energy and network capacity charge had the greatest bill savings for both houses in the three cities. With adoption of PV battery systems, the greatest savings occurred at the households on tariff of critical peak pricing retail energy and network capacity charge. This information is useful for cost-effective use of renewable energy in residential buildings.