The Use of Biomethane in Internal Combustion Engines for Public Transport Decarbonization: A Case Study

Public transport can play a central role in representing a viable and sustainable mobility solution, especially in urban areas. Average energy consumption and emissions per passenger are much lower than for private cars. At the same time, current buses often mostly rely on diesel, and there are different solutions that can contribute to public transport decarbonization. Biomethane is among the options to exploit local low-carbon resources to decrease the emissions of public transport in urban environments. This paper presents the analysis of a real case study considering real data on the fuel consumption and mileage of the existing bus fleet in the city of Turin, Italy, composed by diesel and natural gas buses. The aim of this study is to estimate the effect of different penetration levels of biomethane in substitution of the current fuels. The results show that the use of biomethane in urban buses could save to up to 71% of emissions compared to the current situation, and savings would increase to 75% when deploying biomethane and electric buses together. Average emissions per pkm could decrease from a current level of 85.5 gCO2/pkm to 21.3–63.4 gCO2/pkm depending on the penetration of biomethane and electric buses. The sensitivity analysis shows even higher savings when accounting for the future decrease of the electricity carbon intensity in Italy and for the additional benefits related to avoided emissions from manure disposal. The results of the analysis demonstrate the potential contribution of biomethane in decarbonizing urban buses, and the findings presented for this case study can be of use for policy makers and researchers that deal with a similar situation in other cities and countries

Open data and energy analytics

This pioneering Special Issue aims at providing the state-of-the-art on open energy data analytics; its availability in the different contexts, i.e., country peculiarities; and at different scales, i.e., building, district, and regional for data-aware planning and policy-making. Ten high-quality papers were published after a demanding peer review process and are commented on in this Editorial

Electric vehicle charging network in Europe: An accessibility and deployment trends analysis

If coupled with a low-carbon electricity mix, electric vehicles (EVs) can represent an important technology for transport decarbonization and local pollutants abatement. Yet, to ensure large-scale EVs adoption, an adequate charging stations network must be developed. This paper provides the first comprehensive bottom-up analysis of the EV charging network in Europe. Combining a crowd-sourced database of charging stations with accessibility data and algorithms, we produce maps of the travel time to the most accessible EV charging station across Europe, we evaluate the charging points density and the number of active operators in different areas. We find that although recent years have witnessed a notable expansion of the EV charging network, stark inequalities persist across and within countries, both in terms of accessibility and of the charging points available to users. Our results allow for a better understanding of some of the key challenges ahead for ensuring mass EVs adoption throughout Europe and thus potentially reducing the environmental impact of the transport sector

Carbon Intensity of Passenger Transport Modes: A Review of Emission Factors, Their Variability and the Main Drivers

The transport sector is responsible for a significant amount of global carbon emissions, and several policies are being implemented at different levels to reduce its impact. To properly assess the effectiveness of planned measures, analysts often rely on average emission factors for different transport modes. However, average values often hide significant variability that stems from factors along the entire supply chain of transport modes. This review presents a comprehensive overview of research on this topic, comparing emission factors for different passenger transport modes and discussing the main drivers and parameters that affect their variability. The results are useful for researchers and policymakers to properly understand the reliability of carbon intensity indicators when evaluating the impact and effectiveness of sustainable transport policies

Primary energy consumption of heat pumps in high renewable share electricity mixes

The increase of power plants’ conversion efficiencies, together with the high share of renewable energy sources in the electricity production for some countries, pushes for the use of heat pumps for space heating when aiming at reducing the associated primary energy consumption. However, the effective reduction of primary energy consumption should be supported by careful evaluations, as a number of parameters influence the heat pumps performance, including outdoor temperature, supply temperature, heat load and electricity primary energy factor. The variability of such parameters increases the complexity of the analysis, and annual or monthly average calculations might lead to incomplete evaluations and thus to sub-optimal solutions. This paper performs a hourly simulation of the operation of an air-source heat pump for space heating, relying on the available heat demand data of real buildings currently connected to a district heating network. In addition, the paper proposes the calculation of the hourly primary energy factor of the electricity supplied by the power grid, as the variability of the generation sources plays a key role in the global analysis of the energy system’s conversion efficiency. The results show that in all the considered cases the heat pumps provide potential primary energy savings compared to natural gas boilers, thanks to the combined effect of their high coefficient of performance and the low electricity primary energy factor in the analyzed context. The primary energy consumption reduction obtained in each case is in the range 10–40%, with a median value close to 30%. Moreover, the comparison between average and high-resolution calculations of primary energy factors shows the possible underestimation of the potential primary energy savings when yearly or monthly data are adopted

Open data and models for energy and environment

An increasing number of data sources and models to handle them call for transparency and openness in assessing their goodness and practical use for people. The simplest and most robust tools to collect, process, and analyse data to offer solid data-based evidence for future projections in building and district and regional system planning are of interest. For this purpose, and following the success of the first Special Issue “Open Data and Energy Analytics”, the Special Issue “Open Data and Models for Energy and Environment” has been launched, intended for energy engineers and planners. Among a very high number of submissions, 10 articles were selected for acceptance and published

The potential role of biomethane for the decarbonization of transport: An analysis of 2030 scenarios in Italy

This paper aims at evaluating the best allocation of potential biomethane generation for the decarbonization of the transport system, presenting a case study in Italy. The country has some peculiar features, such as several operating biogas plants, additional potential feedstock for biogas/biomethane generation, a well-developed natural gas network and established relevant natural gas uses in different final sectors, including transport. Based on current estimates for sustainable biomethane potential by 2030, ranging from 2.3 to 7.6 billion cubic meters depending on the scenario, the analysis compares technologies for the generation, distribution and final use of biomethane. The results of the analysis confirm the potential interesting contribution of biomethane in decarbonizing the Italian transport system: a billion cubic meters of biomethane can lead to 2.33–4.37 MtCO2e savings, depending on the feedstock mix and the application. On a national basis, annual climate emission savings in 2030 range from 10.0 to 26.7 MtCO2e, depending on the scenario. Additional 3.1–8.1 MtCO2e of emissions can be avoided if the CO2 captured during the biomethane upgrading can be stored or reused. The proposed methodology could be used to extend the analysis to other countries, and to the European context

Potential Benefits of Remote Working on Urban Mobility and Related Environmental Impacts: Results from a Case Study in Italy

Remote working is increasingly seen as an effective model in several countries in the last decade, mainly thanks to the development of information and communication technologies in support of common daily working tasks. The emergence of the COVID-19 pandemic has represented a pivotal moment for the adoption of remote working in multiple sectors, with positive effects on the environmental impacts caused by the daily commuting of workers. However, due to the fact that pandemic-induced remote working has represented a major forced experiment on a global scale, and that it has often been imposed rather than chosen by employees, workers’ well-being has not always been ensured. This research work presents an analysis of a wide survey of remote workers in public administrations in four different provinces in Italy, with the aim of assessing the main characteristics of the users and the related environmental benefits. Survey data refer to remote workers before COVID-19, thus representing workers who have freely chosen to work from home for different reasons. The results of this work represent a useful tool with which to support the definition of new remote work strategies that could help policy makers reduce a part of the systematic mobility demand. We have also calculated average energy and emission savings to provide useful indicators for a preliminary estimation of the potential environmental benefits of remote working. Considering the entire sample of respondents, workers who would have commuted at least partially by car have saved on average 6 kg of CO2 per day thanks to remote working (with an average round-trip commuting distance of approximately 35 km). The current results will be supplemented by the results of a new survey underway, aimed at evaluating the differences of remote working experiences during the emergency response to COVID-19

Urban mobility demand profiles: Time series for cars and bike-sharing use as a resource for transport and energy modeling

The transport sector is currently facing a significant transition, with strong drivers including decarbonization and digitalization trends, especially in urban passenger transport. The availability of monitoring data is at the basis of the development of optimization models supporting an enhanced urban mobility, with multiple benefits including lower pollutants and CO2 emissions, lower energy consumption, better transport management and land space use. This paper presents two datasets that represent time series with a high temporal resolution (five-minute time step) both for vehicles and bike sharing use in the city of Turin, located in Northern Italy. These high-resolution profiles have been obtained by the collection and elaboration of available online resources providing live information on traffic monitoring and bike sharing docking stations. The data are provided for the entire year 2018, and they represent an interesting basis for the evaluation of seasonal and daily variability patterns in urban mobility. These data may be used for different applications, ranging from the chronological distribution of mobility demand, to the estimation of passenger transport flows for the development of transport models in urban contexts. Moreover, traffic profiles are at the basis for the modeling of electric vehicles charging strategies and their interaction with the power grid

Mapping of Energy Community Development in Europe: State of the Art and Research Directions

Within the framework of defining a new energy paradigm to address climate change and other global challenges, the energy community model is gaining interest in several countries, especially in Europe. This article analyses the literature and experiences of organisational forms that fall under the definition of energy communities in a broad sense, in relation to their ability to bring improvements to the social, environmental and economic dimensions, and to ensure durability and replicability. The main elements that constitute a complete, albeit simplified, model of energy community are identified and analysed. The legislative and regulatory frameworks, technologies and social innovation frameworks, identified here as enabling elements, are discussed, as well as the elements of the energy community business models and the impacts generated at the environmental and energy, economic and social levels. The transformation potential of energy communities is confirmed as more than promising. However, in order to develop as a sustainable and replicable model capable of achieving social and environmental goals, as well as economic stability, further significant research and experimentation, following a cross-sectoral and multidisciplinary approach and strong political leadership, are needed