State-of-the-Art Review of Positive Energy Building and Community Systems

A positive energy system that produces more renewable energy than its demand while ensuring appropriate comfort levels is an excellent path towards increasing the portion of renewable energy, reducing carbon emission, and increasing the energy system's overall performance. In particular, it has been believed as step forward towards zero energy systems. Recent progress in positive energy building and community levels is gaining interest among different stakeholders. However, an inadequate understanding of the positive energy system is widely noticed in many projects, and a shortage of standard details on the positive energy system still prevails in the research community. Therefore, a state-of-the-art review of positive energy building and community is conducted in this paper. Firstly, this paper begins with the definitions and concepts of positive energy buildings and communities. Secondly, it comprehensively describes the energy supplies, demands, indicators, storage, energy management, roles of stakeholders, and bottlenecks of positive energy systems. Thirdly, the main differences between positive energy buildings and communities are summarized. Fourthly, the impact of smart energy grids and new energy vehicles on the positive energy buildings and communities is derived. As a conclusion, this paper shows that even though all the energy-efficient buildings such as passive buildings, nearly zero energy buildings, zero energy buildings, positive energy buildings look like an up-trending scale of renewable penetration, considerable differences are visible among all, and the same thing applies to the community level. Furthermore, considerable differences exist when comparing between positive buildings and communities regarding both the technical and economic perspectives.