A Net-Zero Building Application and Its Role in Exergy-Aware Local Energy Strategies for Sustainability

Sustainable energy solutions that reach beyond the horizon of the present require innovative concepts. This paper analyzes a premier case of a building in Ankara that is ready to meet the net-zero exergy target. It is also the first building in Turkey to be rated Platinum in Leadership in Energy and Environmental Design. A net-zero exergy building (NZEXB) is a building that has an annual sum of net-zero exergy transfer across the building-district boundary. This new target is made possible by a lowered annual exergy consumption (AEXC) and increased on-site production. The modeled results of the building indicate that the reduced AEXC of 60 kWh/m²-yr is met with on-site production of 62 kWh/m²-yr. On-site production includes PV and building integrated PV, a micro wind turbine, combined heat and power, GSHP, and solar collectors. Thermal energy storage facilitates the exergy supply to meet with the exergy demand. The results provide key lessons to structure a more exergy-aware value chain, which are scalable to the district level when the bundle of sustainable energy technologies is zoomed out. These key lessons are compared with two districts in the south heating network of the city of Stockholm, the European Green Capital in 2010, namely Högdalen and Hammarby, whose level of exergy match is found to be 0.82 and 0.84, respectively. The paper concludes that the NZEXB concept has much to offer as a “building block” to structure an exergy-aware energy system for greater sustainability.