From Economic Activity to Understanding Spaces

This paper constructs the probability space underlying the random variable of any time dependent econometric specification. The construction links concrete economic activity, both perceived and recorded, and econometric formulations. Furthermore, it is argued that the probability events belonging to this space are forms of understanding economic activity held by each agent. The model establishes two aspects of any econometric formulation. Mainly, that learning must be unique between any two ticks of the clock and that not all forms of understandings can indeed become events in the random variable’s probability space. Finally, a model of the dependencies based on agent-based understandings, and evolution thereof, is presented as well.Knowledge intuitions probability

Thermodynamic, economic and environmental assessment of energy systems including the use of gas from manure fermentation in the context of the Spanish potential

One of the prospective technologies that can be used for energy generation in distributed systems is based on biogas production, usually involving fermentation of various types of biomass and waste. This article aims to bring novelty on the analysis of this type of systems, joining together thermodynamic, economic and environmental aspects for a cross-cutting evaluation of the proposed solutions. The analysis is made for Spain, for which such a solution is very promising due to availability of the feedstock. A detailed simulation model of the proposed system in two different cases was built in Aspen Plus software and Visual Basic for Applications. Case 1 involves production of biogas in manure fermentation process, its upgrading (cleaning and removal of CO2 from the gas) and injection to the grid. Case 2 assumes combustion of the biogas in gas engine to produce electricity and heat that can be used locally and/or sold to the grid. Thermodynamic assessment of these two cases was made to determine the most important parameters and evaluation indices. The results served as input values for the economic analysis and environmental evaluation through Life Cycle Assessment of the energy systems. The results show that the analysed technologies have potential to produce high-value products based on low-quality biomass. Economic evaluation determined the break-even price of biomethane (Case 1) and electricity (Case 2), which for the nominal assumptions reach the values of 16.77 €/GJ and 28.92 €/GJ, respectively. In terms of environmental assessment the system with the use of biogas in gas engine presents around three times better environmental profile than Case 1 in the two categories evaluated, i.e., carbon and energy footprint.This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 799439. Dr. Martín-Gamboa states that thanks are due to FCT/MCTES for the financial support to CESAM (UID/AMB/50017/2019), through national funds

Review of Life-Cycle Approaches Coupled with Data Envelopment Analysis: Launching the CFP + DEA Method for Energy Policy Making

Life-cycle (LC) approaches play a significant role in energy policy making to determine the environmental impacts associated with the choice of energy source. Data envelopment analysis (DEA) can be combined with LC approaches to provide quantitative benchmarks that orientate the performance of energy systems towards environmental sustainability, with different implications depending on the selected LC + DEA method. The present paper examines currently available LC + DEA methods and develops a novel method combining carbon footprinting (CFP) and DEA. Thus, the CFP + DEA method is proposed, a five-step structure including data collection for multiple homogenous entities, calculation of target operating points, evaluation of current and target carbon footprints, and result interpretation. As the current context for energy policy implies an anthropocentric perspective with focus on the global warming impact of energy systems, the CFP + DEA method is foreseen to be the most consistent LC + DEA approach to provide benchmarks for energy policy making. The fact that this method relies on the definition of operating points with optimised resource intensity helps to moderate the concerns about the omission of other environmental impacts. Moreover, the CFP + DEA method benefits from CFP specifications in terms of flexibility, understanding, and reporting

Revisiting the role of steam methane reforming with CO2 capture and storage for long-term hydrogen production

Road transport is associated with high greenhouse gas emissions due to its current dependence on fossil fuels. In this regard, the implementation of alternative fuels such as hydrogen is expected to play a key role in decarbonising the transport system. Nevertheless, attention should be paid to the suitability of hydrogen production pathways as low-carbon solutions. In this work, an energy systems optimisation model for the prospective assessment of a national hydrogen production mix was upgraded in order to unveil the potential role of grey hydrogen from steam methane reforming (SMR) and blue hydrogen from SMR with CO2 capture and storage (CCS) in satisfying the hydrogen demanded by fuel cell electric vehicles in Spain from 2020 to 2050. This was done by including CCS retrofit of SMR plants in the energy systems model, as a potential strategy within the scope of the European Hydrogen Strategy. Considering three hypothetical years for banning hydrogen from fossil-based plants without CCS (2030, 2035, and 2040), it was found that SMR could satisfy the whole demand for hydrogen for road transport in the short term (2020–2030), while being substituted by water electrolysis in the medium-to-long term (2030–2050). Furthermore, this trend was found to be associated with an appropriate prospective behaviour in terms of carbon footprint.This research has been partly supported by the Spanish Ministry of Economy, Industry and Competitiveness (ENE2015-74607-JIN AEI/FEDER/UE)

Combined use of Data Envelopment Analysis and Life Cycle Assessment for operational and environmental benchmarking in the service sector: a case study of grocery stores

Ensuring sustainable production patterns doing more and better with less is a key sustainable development goal. In this sense, the joint use of Life Cycle Assessment and Data Envelopment Analysis (i.e., the LCA+DEA methodology) arises as a quantitative tool for the eco-efficiency assessment of multiple similar entities. To date, the LCA+DEA methodology has been widely applied to case studies within the primary and secondary sectors. However, the applicability of this combined methodology to case studies within the tertiary (service) sector is still unexplored, which constitutes a current knowledge gap in this field. This work contributes to filling this gap by benchmarking the operational and environmental performance of a sample of 30 groceries located in Spain. All the evaluated groceries were found to involve relative efficiency scores above 0.60, with one third of the groceries deemed fully efficient. Average reductions of 3-26% in the consumption of operational inputs were calculated, leading to average reductions of 9% in the carbon footprint and 10% in the energy footprint. Furthermore, economic savings of up to 3% of the annual turnover were estimated. These results were further enriched through the application of a super-efficiency DEA model for a refined identification of the best-performers, as well as through the novel use of a specific model for the gradual operational and environmental benchmarking of the sample. Overall, a high applicability of the LCA+DEA methodology for eco-efficiency assessment within the service sector is concluded, facilitating the identification and quantification of sustainable operational patterns.publishe

Sustainability-oriented efficiency of retail supply chains: a combination of Life Cycle Assessment and dynamic network Data Envelopment Analysis

Assessing the efficiency of retail supply chains (RSCs) requires analytical tools that address the different activities involved in these chains. In this sense, dynamic network Data Envelopment Analysis (DEA) arises as a suitable method to evaluate the operational performance of RSCs over a period of time. However, its use for sustainability-oriented efficiency assessment constitutes a knowledge gap that limits its applicability for thorough decision-making processes, e.g. at the retail company level. This article fills this gap through the combination of Life Cycle Assessment (LCA) and dynamic network DEA. A novel five-step LCA + DEA approach is proposed and applied to a case study of 30 RSCs in Spain for the period 2015-2017. In this case, the supply chain structure involves three divisions: central distribution, operation of retail stores, and home delivery. Both overall- and term-efficiency scores were found to widely range from 0.38 to 1.00, with only 1 RSC deemed efficient. Regarding divisional efficiency, store operation was found to generally show significantly higher efficiency scores than the distribution divisions. The link between long distribution distances and low efficiency stresses the relevance of integrating a network perspective into the efficiency assessment. In addition to efficiency scores, the LCA + DEA approach enriches the assessment by providing environmental, operational and socio-economic benchmarks to further support the management of RSCs from a sustainability perspective.publishe

Sensitivity of operational and environmental benchmarks of retail stores to decision-makers' preferences through Data Envelopment Analysis

Within the framework of multi-criteria decision analysis (MCDA), weighting methods are typically used to capture decision-makers' preferences. In this regard, the increasing use of the combined LCA (Life Cycle Assessment) + DEA (Data Envelopment Analysis) methodology as an MCDA tool requires an in-depth analysis of how the preferences of decision-makers could affect the outcomes of LCA + DEA studies. This work revisits a case study of 30 retail stores/supply chains located in Spain by applying alternative weighted DEA approaches to evaluate the influence of decision-makers' preferences (weights) on the final outcomes, with a focus on efficiency scores and operational and environmental benchmarks. The ultimate goal is to effectively capture the view of stakeholders when applying LCA + DEA for the sound, sustainability-oriented management of multiple similar entities. Different weight vectors are separately applied to three types of DEA elements: operational inputs, time terms, and divisions. Besides, preferences from three alternative standpoints are considered: company manager through direct rating, and environmental policy-maker and local community through AHP (analytic hierarchy process). A significant influence on efficiency scores and sustainability benchmarks was found when weighting decision-makers' preferences on operational inputs. Additionally, a moderate influence was observed when weighting divisions according to a policy-maker or local community perspective. Although the results are case-specific, they lead to the general recommendation to enrich LCA + DEA studies by following not only an equal-weight approach but also approaches that include the preferences of the stakeholders effectively involved in the study.publishe

Sustainability-oriented management of retail stores through the combination of life cycle assessment and dynamic data envelopment analysis

A sound management of retail stores is a crucial aspect in the path towards a sustainable commercial sector, with a lack of research studies in the field of joint efficiency and sustainability assessment within this sector. In this sense, this work delves into the role of operational efficiency in the sustainability-oriented management of retail stores through the case study of 30 groceries in Spain over the period 2015-2017. With this purpose, and given the current knowledge gap in period-oriented sustainability benchmarking for management plans, for the first time a five-step methodological framework based on the combination of Life Cycle Assessment (LCA) and dynamic Data Envelopment Analysis (DEA) was proposed and applied to a case study within the service sector. The overall- and term-efficiency scores calculated through this method led to the general conclusion of a relatively good performance of the set of grocery stores over the evaluated period, which is associated with the centralised management strategy followed by the retail company. Furthermore, operational, socio-economic and environmental benchmarks were calculated as target values that could assist decision-makers at the retail company level in setting the path for a sustainable operation of the company's stores. Overall, the proposed period-oriented LCA + DEA method proved to be a feasible and valuable tool for sustainability management of retail stores, being preferred over the static (i.e., single term) alternative provided that time-series data are available at the company level.publishe