There is a huge gap between the broad concept of circular economy (CE) and its practical implementation in the industrial sector due to several types of barriers, which shall be led back to the lack of consistent and precise information about resources, products, and processes. Without a proper information flow, it is impossible to quantify circular initiatives, both in comparison with the actual linear situation or with circular alternative opportunities. A proper quantification of circular initiatives allows the assessment of economic, environmental and social benefits and the preventative identification of potential barriers and relative solutions, monitoring the risk associated with circular investments and supporting the decision-making process. This paper describes a new tool to ensure the quantification of circular initiatives and the method to define it. It is a new Circular Business Model (CBM) visualization tool, which overcomes the main limitations of the existing models able to explain CE concepts but not to boost its practical implementation in industry. The new CBM visualization tool can be adopted in every industrial sector to highlight circular opportunities that are still hidden or unexploited or to select the best CE strategy. The proposed CBM visualization tool differs from the previous diagrams in two main characteristics: (i) the possibility to quantify resource flows and important indicators representing energy consumption, environmental and social impact, and (ii) the focus, which is not only on the product, but on the whole system, involving also the process, the company and the entire supply chain. The methodology to adopt and adapt the proposed model to different scales is described in detail. To provide a practical example, the model was qualitatively applied to a generic technical product to highlight its potential in the identification and quantification of circular activities.

The development of sustainable and innovative solutions for the production and supply of energy at district level is nowadays one of the main technical challenges. In the past, district heating and cooling networks aimed to achieve greater energy efficiency through the centralization of the energy production process but with relevant losses related to heat transport. Moving towards a higher share of renewables and lower demand of primary energy requires redesign of the energy district networks. The novel concept of cold district heating networks aims to combine the advantages of a centralized energy distribution system with low heat losses in energy supply. This combined effect is achieved through the centralized supply of water at relatively low temperatures (in the range 10–25 °C), which is then heated up by decentralized heat pumps. Moreover, cold district heating networks are also very suitable for cooling delivery, since cold water supplying can be directly used for cooling purposes (i.e., free cooling) or to feed decentralized chillers with very high energy efficiency ratio. This paper provides a preliminary literature review of existing cold district heating networks and then qualitatively analyses benefits and drawbacks in comparison with the alternatives currently used to produce heat and cold at district level, including the evaluation of major barriers to its further development.

The growing rate of electricity generation from renewables is leading to new operational and management issues on the power grid because the electricity generated exceeds local requirements and the transportation or storage capacities are inadequate. An interesting option that is under investigation by several years is the opportunity to use the renewable electricity surplus to power electrolyzers that split water into its component parts, with the hydrogen being directly injected into natural gas pipelines for both storage and transportation. This innovative approach merges together the concepts of (i) renewable power-to-hydrogen (P2H) and of (ii) hydrogen blending into natural gas networks. The combination of renewable P2H and hydrogen blending into natural gas networks has a huge potential in terms of environmental and social benefits, but it is still facing several barriers that are technological, economic, legislative. In the framework of the new hydrogen strategy for a climate-neutral Europe, Member States should design a roadmap moving towards a hydrogen ecosystem by 2050. The blending of “green hydrogen”, that is hydrogen produced by renewable sources, in the natural gas network at a limited percentage is a key element to enable hydrogen production in a preliminary and transitional phase. Therefore, it is urgent to evaluate at the same time (i) the potential of green hydrogen blending at low percentage (up to 10%) and (ii) the maximum P2H capacity compatible with low percentage blending. The paper aims to preliminary assess the green hydrogen blending potential into the Italian natural gas network as a tool for policy makers, grid and networks managers and energy planners.