Renewable energy generation and integration in Sustainable Buildings – a focus on eco-fuels

This is an O A crucial issue in achieving sustainability from different perspectives is represented by the implementation of renewable energy in current built environment. Architectural constraints of listed buildings, preservation of historical centres or urban morphology are some of the barriers to RES deployment. To face the “renewable's revolution” [1], researchers and scholars should adopt a multidisciplinary approach composed by sensitivity to other fields together with wide knowledge. Sustainable Buildings wants to lead this big challenge, providing contributions from several experts so as to make achievable the sustainability goal. In this framework, my contribution will move towards the discussion on Building and District Sustainable Energy Systems, how and what renewable energy sources could be integrated and, last but not least, how green energy can interact positively with existing building stocks and city organism. From an energy point of view, production, supply and consumption must be considered by all the actors and stakeholders involved in this transition. First of all, the production has to come from dedicated low-carbon and renewable energy sources in order to build a real 100% renewable energy system [1]. Yet, the goal should not exclude certain fossil fuels, such as Natural Gas, that can play a key role in short and medium term decarbonization scenarios [2]. Furthermore, the RES non-programmable nature could be managed with Power-to-Gas (P2G) option. So, energy storage is meant as solution for RES capacity firming. Several P2G solutions are available at each planning and management level from a single building to the National system [3]. Secondly, existing infrastructures cannot be forgotten in the present and future scenarios. Sometimes,