Energy management in combination with photovoltaic electricity improvement of an existing building to approach near zero energy building: A case study

Abstract

Near Zero Energy Building implementation requires effective energy management and sufficient energy production. Thailand follows Energy Efficiency Plan 2018 and Alternative Energy Development Plane 2018, which are the energy reduction plan and alternative energy production plan, respectively. However, these plans are country scale guidelines, neither of them provides detail on a building or a household scale. This paper presents a case study of energy improvement on an existing building. The pre-improvement energy consumption was analyzed in detail. Accordingly, both energy reduction measures combine with PV energy production together with energy storage were deployed. Post- improvement energy consumption and production are discussed and Near Zero Energy Building an index is proposed. The results show that the energy reduction measures decrease the specific energy consumption of the pre-improvement energy consumption down 38.82%, which is from the value of 116.02 kWh/m2-yr to 70.99 kWh/m2-yr. Together with PV production, which generates electrical energy with the amount of 50.4 kWh/m2-yr, the net specific energy consumption of the sample building is 20.59 kWh/m2-yr. However, the installation cost of PV system is higher than the energy reduction cost. This makes increasing energy production to cover pre-improvement energy consumption financially impractical. The management of energy production and energy reduction should be deployed together to make a Near Zero Energy Building financially practical.