Demand-Side Flexibility for Community Benefits and Distribution Network Deferral: A Case Study of a New Zealand Island

The decarbonisation of the energy system is accelerating the uptake of distributed and renewable energy resources. Nevertheless, this stresses already-constrained distribution networks, and it can lead to expensive grid infrastructure upgrades. Demand-side flexibility offers a non-network solution that can reduce power grid reinvestment and reinforcement. This paper investigates the potential of demand-side flexibility, where we explore community energy sharing and coordinated demand response through a data-driven case study for Waiheke Island, New Zealand. In particular, a demand-response management framework is developed that coordinates household hot-water cylinders, EV charging, rooftop solar power, and home and community battery storage. The framework is first evaluated in a community-scale energy-sharing scenario that incorporates flexible load scheduling and market-level settlement. The analysis is then extended to the entire Waiheke Island under a realistic demand-response setting, supported by a digital representation of the island’s electricity network and energy system. The study integrates real household smart-meter data, feeder-level consumption data, and information obtained from multiple publicly available sources to assess the island-wide potential for demand-side flexibility. Detailed simulations show that rescheduling hot-water cylinder operation, EV charging, and household battery storage can substantially reduce the island’s evening peak demand, thereby delaying network reinforcement and generating significant economic benefits.