Optimal design and operation of distributed electrical generation for Italian positive energy districts with biomass district heating

Abstract

The active participation of prosumers within the energy generation and distribution stages has revolutionized the energy market favoring the rise of decentralized energy supply configurations and representing a key path for targeting the transition towards sustainable and energy-efficient urban areas. The new Renewable Energy Directive 2018/2001 regulates the constitution of renewable energy communities and promotes the exploitation of solid biomass, biofuels, and biogas for district heating. In addition, energy communities can be considered Positive Energy Districts in case of an annual net-zero energy import and local surplus of renewable production. In alignment with these regulatory frameworks, this research proposes a model for the design of prosumer-centered thermal and electrical grids pointing to a positive balance between production and consumption. In detail, this research contributes to the (i) design of the electrical and thermal distribution grids, (ii) configuration of the optimal exchange scheme for electrical distribution among prosumers, and (iii) valorization of the eventual positive surplus. The model is discussed for a candidate Positive Energy District in a real urban neighborhood in Sicily. Results demonstrate a good rate of interconnections among buildings in the area, especially in a spatial range of 200 m with almost 44 % of distributed electricity production. From the environmental viewpoint, 73 % of CO2 emissions are avoided in comparison with the centralized electrical supply, whilst 55 % of emissions reduction has been estimated from biomass district heating, thus posing favorable conditions for a possible transition of the existing area towards the Positive Energy District model.