Zero energy building (ZEB) in a cooling dominated climate of Oman: Design and energy performance analysis

Zero energy buildings (ZEBs) are targeted by several developed countries around the world which consequently promotes the progress toward achieving ZEBs. The concept of ZEBs is, however, uncommon in developing economies such as Oman. In 2011, The Research Council of Oman has announced a competition to design, construct and operate buildings that embrace sustainability principles. The first five eco-friendly buildings were designed and constructed by academic institutions in different climatic conditions of Oman. This project has significantly contributed toward raising awareness of energy efficiency and renewable energy systems in buildings. This paper outlines the design of sustainable energy systems of one of these five buildings. The ZEB prototype is located at the Sultan Qaboos University campus in Muscat, which is an extremely hot climate as classified by the ASHRAE Standard 169-2013. The ZEB building was designed with full manipulation of natural energy. This paper also reports the experimental results of its one year of operation. The results showed that energy use intensity (EUI) of 103 kWh/m² was achieved by this building. The building was less than 3% from achieving its net-zero energy source/site/emissions status. Nonetheless, it was able to achieve a positive energy cost status because of the financial credits received from the exported energy, which is subjected to high cost feed-in tariffs. When grid interaction was considered, 40% of the building load was met by site generation. For 33% of the time, this building was independent of the electrical grid, which is comparable to other net-zero energy buildings located in other climates. While several experimental studies for ZEB performance have been described in literature for heating dominated climates, very few experimental studies have been published for cooling dominated climates. Hence, this study aims to fill the gap in the knowledge of energy performance of ZEBs located in this region.