Deep retrofitting toward net zero energy building in the Mediterranean region: A case study of Albania

Like many other Mediterranean countries, Albania faces unique challenges and opportunities to achieve an efficient and fully decarbonized household sector by applying real energy efficiency measures and numbers toward nearly zero-energy buildings. The study findings showed that nZEB in 2030 can be achieved by combining active and passive energy efficiency measures. Behind the study's state-of-the-art stands a multivariable regression analysis of both electricity consumption and electricity generation executed for three validated consecutive years, 2021, 2022, and 2023, including demand side (electricity bills) and supply side generation provided from a nearby existing onsite PV with an installed capacity of 5.5 kWp. A good mathematical correlation is carried out using Durbin – Watson criteria on statistics using RETScreen software to correlate electricity consumption and generation as a function of weather parameters for the tested household and selected region. The goals to meet the nZEB concept require the insulation of the existing exterior wall and window replacements in compliance with the Energy Performance Methodology on Building and installing rooftop Solar Water Heating (SWH) panels of 3.73 m² as expostulated in scenario 7. The simulation results show that integrating a rooftop PV system with an installed capacity of 5.5 kWp would provide enough electricity to convert residential buildings into Positive Energy Buildings in 2050 based on the selected dwelling and location (Mediterranean region). At the national level, the proposed model would reduce the national annual electricity import level by 1.64 %, saving annually around €31,021,162 and reducing at least 0.068 MtCO₂ per year. Subsidizing passive energy efficiency measures at a rate of 3 % per year coupled with onsite renewable energy sources schemes and other incentivization pathways from the government and other interested parties at a rate of 80 % in the roadmap towards nZEB and PEB is mandatory.