Nearly 40% of the total greenhouse gases (GHGs) are emitted from the energy consumption in buildings in Japan, which should be reduced to address global warming. A hydrogen energy utilization system with renewable energy (RE) was designed by MATLAB/Simulink simulations for realizing a zero emission building (ZEB), comprising a hydrogen-producing electrolyzer, a hydrogen storage tank, fuel cell, and battery for short-term power storage with estimated specifications of 3.0 Nm(3)/h, 36 Nm(3), 4.2 kW, and 10 kW/17 kWh, respectively. We identified a small low-rise building (total floor area: similar to 1000 m(2), demand: similar to 5 kW) as the planned ZEB to construct and operate a bench-scale system. A 20-kW photovoltaic (PV) system was selected as the RE source. Two hydrogen production processes (constant power of 10 kW or with excess PV power) were evaluated by simulating 48-h operations on fine and cloudy days, where the former showed higher efficiency. The results with excess power on a fine day agreed well with that of actual operation, validating our simulation models. Further, the constant case was suitable for practical application. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.