Building integrated energy systems for southern European buildings

Abstract

Improving energy efficiency has become a priority for most countries. This can be achieved by reducing the energy consumption or by producing renewable energy. According to the Near-Zero Energy Building (NZEB) Plan for Malta this renewable energy is mostly limited to solar based renewables. In this regard, this study explores the potential for the use of Building Integrated Photovoltaics (BIPVs) in Malta, and deals with their technical and economic aspects. BIPVs are viewed as an effective means for energy generation in numerous countries, yet their use in Malta has remained low. A typical block was modelled in order to assess the sensitivity of orientation and shading on the performance of these BIPVs. Furthermore, two case studies were modelled and simulated using an online simulation tool, PVGIS, in order to derive the potential energy which could be generated through the use of BIPVs. It is well known that for roof mounted systems, a true south orientation generates the highest amounts of energy for Malta's climatic conditions. Nevertheless, results from this study show that there is a window of opportunity for energy generation up to azimuth angles of ±30° in the case of BIPVs. For both buildings studied, the energy generated from BIPVs could substitute approximately 10% or more of the energy demand for that same building. The results obtained from the modelling were then used as input parameters to analyse the feasibility of these systems. In this regard, a fiscal assessment was performed for a full cost model analysis and a fiscally aided model. The latter was used to assess financial viability following the introduction of grants and Feed-intariffs (FIT). Results showed that whereas the model was feasible for building integrated polycrystalline photovoltaics, the financial performance diminishes when including transparent thin-film systems. FIT and grants play an important role on the financial feasibility of the system. Furthermore, the greater the usable area covered by BIPVs the more feasible the model is. This study has shown that if properly designed and certain barriers to BIPVs are removed, the use of these systems could lead to significant progress towards reaching near-zero energy buildings. This study shows the potential for BIPVs to become part of common practice in future local building design by architects.