Building Integrated Photovoltaic Systems as a Sustainable Option for Retrofitting of Office Buildings in South East Europe

Abstract

The need for rational energy consumption and measured use of resources dictates a new approach to designing, constructing, and renovating existing buildings. This paper focuses on one of the main energy consumers within the built environment, office buildings. In order for office buildings to comply with the targets set for 2020 by the Energy Performance of Buildings Directive, extended refurbishment of the existing building stock is required, combined with utilizing renewable energy technologies. Although there are various strategies available for renewable energy generation in urban environments, facade BIPV integration offers a great potential of generating electricity, despite the limited roof space of multistory buildings. The case of buildings in Southeast Europe is of special importance, as due to the prevailing climatic conditions, cooling loads are usually higher than heating loads, making retrofitting a more complex problem than simply increasing the insulation levels. For the scope of this paper, the facade redesigning of a typical nine-story office building in Greece is examined as a sustainable option towards transforming it into a nearly Zero Energy Building (nZEB). In order to achieve greater energy performance, an energy simulation model is developed in EnergyPlus and TRNSYS, to calculate the energy savings and electricity production through the proposed retrofitting options. The BIPV systems are estimated to produce electricity that covers approximately 50% of the building's total annual energy demand and upgrade its aesthetics and architectural form. Moreover, various orientation scenarios are evaluated, to better understand the behavior and retrofitting potential of offices scattered throughout the urban environment of Southeast Europe.