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Commercial buildings are responsible for a significant share of the energy requirements of European Union countries. Related consumptions due to heating, cooling, and lighting appear, in most cases, very high and expensive. Since the real estate is renewed with a very small percentage each year and current trends suggest reusing the old structures, strategies for improving energy efficiency and sustainability should focus not only on new buildings, but also and especially on existing ones. Architectural renovation of existing buildings could provide an opportunity to enhance their energy efficiency, by working on the improvement of envelopes and energy supply systems. It has also to be noted that the measures aimed to improve the energy performance of buildings should pay particular attention to the cost-effectiveness of the interventions. In general, there is a lack of well-established methods for retrofitting, but if a case study achieves effective results, the adopted strategies and methodologies can be successfully replicated for similar kinds of buildings. In this paper, an iterative methodology for energy retrofit of commercial buildings is presented, together with a specific application on an existing office building. The case study is particularly significant as it is placed in an urban climatic context characterized by cold winters and hot summers; consequently, HVAC energy consumption is considerable throughout the year. The analysis and simulations of energy performance before and after the intervention, along with measured data on real energy performance, demonstrate the validity of the applied approach. The specifically developed design and refurbishment methodology, presented in this work, could be also assumed as a reference in similar operations.

Abstract Industry is one of the highest energy consumption sector: some facilities like steelworks, foundries, or paper mills are highly energy-intensive activities. Many countries have already implemented subsidies on energy efficiency in generation and utilisation, with the aim of decreasing overall consumption and energy intensity of gross domestic product. Meanwhile, researchers have increased interest into alternative energy systems to decrease pollution and use of fossil fuels. Hydrogen, in particular, is proposed as a clean alternative energy vector, as it can be used as energy storage mean or to replace fossil fuels, e.g. for transport. This work analyses the re-vamping of the energy generation system of a paper mill by means of reversible solid oxide cells (RSOCs). The aim is not only to increase efficiency on energy generation, but also to create a polygeneration system where hydrogen is produced. Application on a real industrial facility, based in Italy with a production capacity of 60000 t/y of paper, is analysed. First, the current energy system is studied. Then, a novel system based on RSOC is proposed. Each component of the systems (both existing and novel) is defined using operational data, technical datasheet, or models defined with thermodynamic tools. Then, the interaction between them is studied. Primary energy analysis on the novel system is performed, and saving with respect to the current configuration is evaluated. Even if the complexity of the system increases, results show that saving occurs between 2 and 6%. Hydrogen generation is assessed, comparing the RSOC integrated system with proton exchange membrane (PEM) electrolysis, in terms of both primary energy and economics. Results exhibit significant primary energy and good economic performance on hydrogen production with the novel system proposed (hydrogen cost decreases from 10 €/kg to at least 8 €/kg).

Abstract The sustainable indicators are characterized by a low degree of aggregation and a high amount of information. An indicator must show a synthetic representation of a real environmental, by using a value or a parameter, so that they can be easily used by policy makers. It is necessary to connect, therefore, the various systems in an appropriately integrated sustainable system. The indicators need to be aggregated based on the structure of the data. Each indicator must to be defined through a weight with reference to another weighted indicator. In this paper is illustrated the calculation of the assigned weights that uses a procedure based on fuzzy logic and to define a model that allows us to estimate the sustainability of a city. The final result is, therefore, a combination of values assigned by expert opinion for the various criteria, processed using fuzzy logic to obtain a weight with significant objectivity and as it is possible to estimate the sustainability of the city through the weights.

This paper illustrates the main results of an expert elicitation survey on advanced (second and third generation) biofuel technologies. The survey focuses on eliciting probabilistic information on the future costs of advanced biofuels and on the potential role of Research, Development and Demonstration (RD&D) efforts in reducing these costs and in supporting the deployment of biofuels in Organisation for Economic Co-operation and Development (OECD) and non-OECD countries. Fifteen leading experts from different EU member states provide insights on the future potential of advanced biofuel technologies both in terms of costs and diffusion. This information results in a number of policy recommendations with respect to public RD&D strategies and is an important contribution to the integrated assessment modelling community.

This work reports the measured and derived quantities of an experimental campaign conducted in an existing laundry to record the conditions of the exhaust air of a batch industrial natural gas-fired dryer for cotton flat fabrics, like bed linens or tablecloths. The load of fabrics is 85 kg, referred to the dry fabric. The measured quantities are temperature and velocity in the center of a squared exhaust duct, which are reported along with their measurement uncertainty. The derived quantity is the exhaust air mass flow rate along with its combined uncertainty. In particular, these data can be used to study the feasibility of waste heat recovery strategies, such as that studied in the related research article "Optimal cascade phase change regenerator for waste heat recovery in a batch industrial dryer" [1].

Abstract With environmental concerns and limited natural resources, there is a need for cleaner sources of energy in the transportation sector. Renewable natural gas (RNG) is being considered as a potential fuel for heavy-duty applications due to its comparable usage to diesel and gasoline in vehicles. The idea of compressed RNG vehicles is being proposed especially because it will significantly reduce harmful emissions into the environment. This study examines the feasibility of implementing a nationwide network of compressed RNG refueling infrastructure in order to accommodate a conversion of long-haul, heavy-duty (LHHD) truck fleet from diesel fuel to RNG. Two methods, Constant Traffic and Variable Traffic, along with data about compressed RNG infrastructure and vehicles, were developed and used to predict fuelling requirements for LHHD truck fleet. Then, a detailed economic analysis was conducted on various test cases to estimate how different variables impact the final selling price of RNG. This provided insight with the understanding of what factors go into pricing RNG and if it can compete against diesel in the trucking market. Results disclosed that the cost to purchase RNG is the greatest factor in the final selling price of compressed RNG. Due to the variability in RNG production, however, there is no precise cost, which makes predictions challenging. However, results revealed that it is possible for compressed RNG to be competitive with diesel, with the mean compressed RNG price being 16.5% cheaper than diesel, before being taxed. Future studies should focus on the feasibility of the production of RNG and the associated costs. An in-depth analysis on operational and maintenance costs for compressed RNG refueling stations may also provide predictions that are more accurate. The methodology developed in this feasibility analysis may serve as a useful tool for future techno-economics of RNG refueling stations for other types of internal combustion engine (ICE) fleets or those powered with alternative green fuels.

Co-design approach is increasingly popular in many organizations that address global change and social sustainability challenges, thanks to its unique and diverse methods of engaging relevant people in design processes and decision-making. However, the social distancing led by the COVID-19 pandemic seriously problematized the traditional in-person co-design activities. A sustainable online transition is unprecedentedly pressing. By acknowledging the limitations of online co-design, i.e., lack of means for participant engagement, we argue that gamification holds great promise for online co-design. This paper presents an empirical study to investigate this potential qualitatively. Based on the data collected from three gamified online co-design implementations, we examine the benefits of gamification and how future activities should be designed and implemented from the participants’ perspectives. Based on the participants’ perceptions, we propose several recommendations for designing impactful gamification. The finding suggests that gamification can facilitate online co-design activities in an enjoyable, relaxing, structuring, and creative manner, since they are perceived and recognized by the participants. Moreover, the successful implementation of online co-design implies that great sustainability benefits can be achieved through online transition, i.e., reducing paper consumption and time spent on meetings and unproductive discussions, supporting extensive diversity and density in representation. Online can enable this by overcoming not only the geographic and time limitations but also relevant social issues.