Managing solar abundance through smart household flexibility: A socio-technical assessment of Australia's Solar Sharer Offer

Abstract

Australia's rapid growth in rooftop photovoltaic generation is creating periods of low operational demand, negative wholesale prices and renewable-electricity surplus. Tariff-based demand response may help align household consumption with these periods, but its contribution depends on resource capability, availability, accessibility and delivered response. This study develops a socio-technical assessment of Australia's Solar Sharer Offer, which provides eligible households with a 3-h zero-price electricity window. The framework integrates a Flexibility Access Assessment with household load-shifting, aggregate participation, bill-impact and sensitivity analyses, supported by empirical plausibility benchmarking. Five stylised household configurations provide 0-12 kWh of flexible energy per event. Delivering a 263 MW demand increase for 3 h requires 1.315 million appliance-only households or 65,750 highly automated households under ideal conditions; with 75% resource availability and 80% response delivery, these requirements increase to approximately 2.19 million and 109,583, respectively. Using matched 2026-27 tariffs, central annual household net value ranges from -AUD 100.9 to AUD 954.2, depending on flexibility capability and whether free-period savings offset the approximately 2.62 c/kWh higher SSO charge on remaining non-free consumption. Australian trials support the plausibility of selected flexibility assumptions but do not validate voluntary Solar Sharer Offer response. The results show that tariff signals can support renewable-energy absorption, but their system value depends on delivered flexibility, coordination and equitable access to enabling technologies.