Best Practices for Recovering Rural Abandoned Towers through the Installation of Small-Scale Biogas Plants

The massive and continuous development of renewable energy systems is making it possible to achieve the European goals regarding environment and sustainability. On the other hand, it leads to the progression of significant problems such as low renewable energy density (i), social acceptability (ii), and non-programmability of renewable energy sources (iii). The rural architecture, which is largely present in the countryside of central Italy, is generally equipped with several annexes such as dovecotes (i), grain stores (ii), and tobacco drying kilns (iii). Nowadays, those towers appear in decay because of the decline of agricultural activities, although they are classed as Environmental and Historical Heritage sites. The present work aims to propose a methodology for improving the energy grid in the countryside, while reusing abandoned buildings by modifying their function and maintaining their aspect as much as possible. The proposed workflow was applied to a rural silo, which has fallen into disuse, in Sant'Apollinare (Marsciano, Perugia) by converting it into a mini-biogas plant. The function of the annex which was chosen as the case study changes from agricultural use to energy production: it becomes an on-site renewable energy-based electric grid that can produce clean energy from agricultural and forestry residues. The project turns out to be sustainable not only in terms of energy and the environment, but also from an economic point of view as a result of the recent regulations and incentives for renewable energy production.