An energy performance monitoring, analysis and modelling framework for NetZero Energy Homes (NZEHs)

Abstract

NetZero Energy Homes (NZEHs) are designed to achieve zero energy balance annually (i.e., produce approximately as much energy as consume). In this context, the actual energy performance of NZEHs must be examined and assessed to verify the design assumptions. In this paper, an energy performance monitoring and analysis framework is proposed for NZEHs, and a NZEH in Edmonton, Canada is analysed as a case example, which is found to have an energy deficit of 669.38kWh (4.1% of total consumption) for the first monitored year. The actual energy performance is analysed with great detail, among which the energy consumption is analysed by category of occupant-driven and less-occupant-driven. Based on the categorization and the analysis, both polynomial and regression models are proposed for the energy consumption modelling. The monitored results are also compared with that of simulation models. Overall, the NZEH consumes 14.4% less than estimated, and generates 10% less than predicted; the differences and the reasons are analysed by category of space heating and cooling, domestic hot water (DHW) heating, heat recovery ventilator (HRV), base loads, and energy generation. This research proposes a generic framework of energy monitoring, analysis, and modelling for NZEHs, which provides feedback for NZEH operation, and yields information for the future design.