Implementing Renewable Energy Systems in Nearly Zero Energy Communities

Abstract

The sustainability challenges involve the built environment responsible for a large share in the total energy consumption. Steps toward a sustainable path were formulated and started to be implemented all over the world and, it is important to notice that the technical focus is mainly set on the energy production and consumption. Thus starting from the already formulated concept of Nearly Zero Energy Buildings (nZEB) and from the lessons learned when implementing it, this paper presents a study on the development of a Nearly Zero Energy Community (nZEC). The Community of the R&D Institute of the Transilvania University of Brasov was built starting with 2009 till 2013 and consists of 12 low energy buildings hosting 29 R&D Centers. The energy consumed in 2015 and 2016 in this community was monitored and a seasonal variation was registered for both, electrical and thermal energy. It was observed that the variability in the thermal energy demand is much larger and has a specific trend for each year. This community has partially installed renewable energy systems and their output is registered and discussed, considering the consumption variability over the year aiming at delivering a preliminary assessment of the renewable energy systems that can insure the Nearly Zero Energy (nZEC) status to this micro-community. The results show that the electrical energy produced should give full use of the current existent transportation and distribution infrastructure, while the thermal energy should be well managed at the micro-community level, to reduce the losses. An average share of 50% renewable energy was found to be able to cover the total energy demand in the laboratory buildings and in the R&D micro-community, confirming its goal as nZEC.