Development of integrated energy sharing systems between neighboring zero-energy buildings via micro-grid and local electric vehicles with energy trading business models

Applying high-efficient combinations of renewable energy systems and effective energy management of renewables, grid and storage resources between neighboring grid-tied zero-energy buildings (ZEB) has become growingly significant to improve the techno-economic performance of hybrid building systems. However, majority of the existed research mainly analyzed one single energy-sharing method based on simple technical yearly index. The techno-economic impact evaluated by matching index (WMI) and net present value (NPV) of various hybrid renewable energy systems combined with three different integrated building energy-sharing systems via instantaneous and predictive micro-grid-based, and local electric-vehicle(EV)-based energy-sharing remains uncovered. The research results show that with integration of instantaneous micro-grid-based and local-EV-based energy-sharing system, the techno-economic performance is enhanced (average WMI improved by 7.19 % and 6.86 %, NPV improved by 9.53 % and 5.70 %, respectively), while specific cases show various improvement outcomes largely related to the types of renewable combinations. Under instantaneous micro-grid-based sharing, the divergency of two buildings' renewable combinations brings at most 33.59 % technical improvement and 3,764,380 HKD economic benefits. In contrast, the similarity of both renewable combinations helps achieve a maximum 12.02 % matching enhancement and an extra 866,690HKD NPV improvement under local EV-based energy-sharing. As for the common energy trading business model, the building with more energy shared earns more profits as the trading price increases. However, when the residence is under the “Predictive Micro-grid-based Energy-Sharing Control” mode, a lower trading price below 0.5 HKD of the specific case is more likely to minimize the loss of office stakeholder as well as maintain positive profits of residence owners.