Development of a New Residential Energy Management Approach for Retrofit and Transition, Based on Hybrid Energy Sources

The building sector contributes to a significant part of growing global energy demand. Improving the energy efficiency of the existing building stock is a crucial strategy. Adopting the best energy retrofit strategy in a specific building is a hard task due to the multitude of possible combinations of retrofit measures and the management of different renewable energy sources in the building. However, significant efforts must be made to combine envelope retrofit with renewable energy to improve the energy efficiency of existing buildings and minimize the energy payback period and greenhouse gas (GHG) emissions. It also helps to achieve a successful transition to zero fossil fuel energy for houses and an existing housing stock free of greenhouse gas emissions. This paper is based on a systematic approach, which was applied to an Algerian case study “high-rise building/housing units” that represented southern Mediterranean countries. The percentage of energy consumption was identified; moreover, the performance of on-site hybrid exploitation of renewable energy systems such as photovoltaic cells, thermodynamic panels and small wind turbines was proven. Several actors have collaborated and a range of software types have been used (3D modelling, meteorological regeneration data, energy simulation of buildings, estimation of renewable energy production and statistical analysis). As a result, the building case study has become more efficient than before, whereas the payback time was 10 years. The economic and environmental analysis highlighted that it is possible to save energy demand by up to 51–75% for heating and up to 5–32% for cooling; electricity and hot water consumption was covered at 98% and 80%, respectively, whereas associated gas emissions are reduced by up to 252 tons per building, a reduction of 91%. The model of the platform designed is multi-disciplinary, facilitating collaboration with the various stakeholders to identify directions for successful interventions in pre-established cities. It is a solid framework for future research aimed at standardizing the approach to energy retrofitting and transitioning in existing buildings and is suitable for all types of residential buildings of the southern Mediterranean region such as Algeria, Tunisia and Morocco.