Solar application in buildings is limited by available installation areas. The performance of photovoltaic (PV) and solar collectors are compared in meeting the heating and cooling demand of a residential house using 100% solar energy through TRNSYS modelling of five systems that use air source heat pump and seasonal energy storage as optional assisting technologies. The results show that in a large scale, the PV working with air source heat pump is more efficient than the solar collector system. However, the photovoltaic/thermal (PV/T) is the most spatially efficient with an energy capacity of 551 kWh/m², 10.6% higher than that of the PV. Compared with the air source heat pump heating system using grid power, using solar energy regardless of system formats can reduce emission by 72% in a lifetime of 20 years. Solar energy can become cost-effective if the utility price is increased to above 0.7 CNY/kWh. The results can help in renewable planning in the studied climate.

Under rapid urbanization-induced global warming and resource depletion, growing interest in zero-energy building (ZEB) and zero-emission building (ZEB) technologies have emerged globally to improve energy performance in homes and shape sustainable cities. Although several countries have released ZEB-enhanced strategies and set national standards and policies to promote ZEBs, construction projects are still limited to demonstration projects. This paper reviews global ZEB activities and state-of-the-art technologies for energy-efficient residential building technologies [based on an evaluation of 40 residential buildings]. Over 40 residential buildings on different continents were reviewed, and their technical details and performance were evaluated. Our results show that 62.5% of the buildings achieved the +ZEB standard, 25% of the buildings were net-zero energy buildings, and only 12.5% of the buildings were near-zero energy buildings. Solar PV is the most widely used renewable energy source in the studied cases, while in warmer climates, advanced cooling technologies and heat pumps are the preferred technologies. A building envelope and thermal ventilation with heat recovery are essential in cold climates. Our systematic analysis reveals that the thermal performance of the building envelope and solar energy are the most effective mechanisms for achieving energy efficiency and shaping sustainable cities.