Flexible coupling and grid-responsive scheduling assessments of distributed energy resources within existing zero energy houses

Abstract

Technological advancement and supportive government policy have accelerated investments in distributed energy resources (DERs) in buildings, demand-side management has become essential to fully exploit their value, including demand flexibility and grid support. Using high-resolution smart-meter data, this work presents an optimization framework for assessing the flexible scheduling of coupling distributed resources in existing zero energy houses (ZEHs) in Kyushu, Japan. Two price-based energy management programs are investigated for different energy coupling models with associated variables and constraints. Specifically, demand sides are encouraged to adjust energy usage and grid feed-in photovoltaics (PV) generation following a fixed Feed-in Tariff (FiT) value or market-oriented Feed-in Premium (FiP). The scheduling results present the impacts of proposed dispatch strategies on PV consumption and grid interactions. Results show two price-following strategies result in significant differences in dynamic grid feed-in power flows, the trade-off between dynamic PV self-consumption and grid import helps reduce the annual energy cost to feed PV generation by matching real-world spot prices. The improvement of PV self-consumption through coupling strategies has a close relationship with the pattern of household demand profiles. The energy flexibility potential of the heat pump system is constrained by daily hot water demand, flexible scheduling of coupled PV/battery/heat pump systems achieves the highest PV self-consumption ratios. The flexible dispatch of battery storage systems presents reliable performances in increasing on-site PV self-consumption and reducing annual household energy costs, the effects of storage charging rates on cost savings are less, especially for larger capacity batteries. Findings may help design sustainable and equitable pathways for decentralized solar PV system deployment.