Optimizing energy yield and economic benefit of renewable energy technologies in Maltese dwellings

Abstract

In the EU, residential final energy consumption amounts to 27% of the total (2020), while in Malta, the respective value adds up to 17.2% (2018). The EU’s strategy towards decarbonizing energy flows in households consists of either increasing the overall energy efficiency of buildings or else offsetting the energy demand through the implementation of renewable energy sources. In this regard, Malta is a highly populated small island nation, with limited space available for the large-scale implementation of clean energy installations. Hence, in the past decade, the implementation of renewable energy sources (RES) technologies in residential dwellings has proven to be of utmost significance for the country to reach the renewable energy (RE) targets set by the EU Renewable Energy Directive (RED). As such, this study was designed to explore how RES implementation in Maltese dwellings may be optimized so that the existing RE potential of the residential building stock is reached. By combining the most applicable RES technologies with the most prominent types of dwellings in Malta, a set of typical configurations was generated. Their techno-economic performances were then characterized through energy yield simulations using Polysun software, followed by an economic benefit analysis for each case. Data was also collected by means of a questionnaire from Maltese residents, which was processed and referenced throughout the project work. By identifying those factors with the largest impact on performance, a sensitivity analysis was then conducted to establish the variation in energy yield and economic benefit in comparison to the reference scenarios. The final step was to observe and compare the results obtained from the questionnaire responses and reference and sensitivity analyses. Conclusions were made vis-à-vis the implications that variations in the identified factors have on the energy yield and economic benefit of practical RES configurations. The significance of shading, fiscal support mechanisms, dwelling occupancy, and electricity tariffs, among other aspects in relation to RES implementation in dwellings, was highlighted. Lastly, recommendations were made to private investors as well as local policymakers regarding their approach to addressing the synergistic impact of these factors to prioritise investments in renewable energy and fine-tune or devise new grant schemes to further tap the renewable energy resources available in Malta.