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Highlights: [•] The model proposed aims at minimizing local impact of energy systems. [•] The model is meant to minimize the impact starting from system thermodynamics. [•] The formulation combines exergy analysis and quantitative risk analysis. [•] The approach of the model is dual to Thermoeconomics. [ABSTRACT FROM AUTHOR]

Understanding the energy metabolism of national economies is nowadays crucial for policymakers in order to define effective policies and to properly set energy efficiency targets. Energy accountings based on the traditional Production-based accounting method (PBA) allows to understand how primary energy is directly extracted, traded, transformed and used within each economy. On the other hand, Consumption-based accounting method (CBA) allows to understand the ultimate economic purposes of such energy flows. The information provided by the joint application of these approaches may provide useful and complementary insight on the national energy metabolism, allowing to identify hotspots for potential interventions from both the supply and demand side. This paper reviews PBA and CBA energy accounting methods, presenting a possible way for the joint use of their results, consistently represented by means of one unique Sankey diagram. This will be useful to have a comprehensive insight on the energy metabolism of national economies, supporting analysts and policymakers in the identification of energy efficiency hotspots. The method is applied to South Africa and to the neighbor country of Botswana, based on data provided by IEA energy statistics and the EORA26 Multi-Regional Input-Output model, taking into account non-renewable fossil energy (raw coal, crude oil and natural gas) and considering the reference year 2013. Results suggest that the joint use of PBA and CBA methods may provide useful information on the hidden energy links among national economies, helping analysts and policymakers in defining alternative energy efficiency policies. For this reason, the Authors argue that results of CBA should be provided alongside energy statistics based on the traditional PBA approach. [ABSTRACT FROM AUTHOR]

Exergy Life Cycle Assessment (ELCA) is proposed by literature to account for the exergy embodied in products of energy systems. In order to make results of ELCA comparable, supply chains that support the life cycle of the system should be analyzed through a unified model: this is one of the main concerns related to Life Cycle Assessment and Industrial Ecology disciplines. In this paper, Hybrid Input-Output analysis is proposed as the computational structure of ELCA: according to this method, national supply chains are modeled through the Monetary Input Output Tables (MIOTs) of national economies, a constantly updated and freely available data source. Then, the adopted national MIOT is expanded to include the detailed model of the considered energy system, hence defining a Hybrid Input-Output model. The (non-renewable) exergy embodied in electricity production and the Exergy Return on Investment (ExROI) are defined as the appropriate performance indicators based on ELCA. The introduced model is here adopted for the analysis of a Waste-to-Energy (WtE) power plant currently operating in the Italian context. It is found that the primary non-renewable exergy embodied in electricity produced by the analyzed WtE is non-negligible for both the construction (127.1 toe) and the operation phases (11.6 toe/y). Nonetheless, the plant is able to produce a net amount of electricity that pays back such primary non-renewable resources requirements about a hundred times. Finally, the joint application of Exergy Analysis and ELCA lead to improve the overall thermodynamic performances of the WtE system, increasing its exergy efficiency by 1%, and reducing the non-renewable exergy embodied in electricity production by 7938 toe. [ABSTRACT FROM AUTHOR]

Less than 15% of rural areas of Cameroon have access to grid electricity. Only 53% of the population has access to grid electricity. Notwithstanding, Cameroon has a huge hydropower potential which could be harnessed. Mini grids, powered by pico and micro hydropower plants, are a relatively new rural electrification strategy in Cameroon. Several of such mini grids have been realized in the mountain regions of the country. Some of these systems have been more successful than others. This paper aims to share the experiences of community-based pico and micro hydropower schemes for rural electrification in Cameroon. The paper provides insight to the challenges that three of such mini grid systems powered by pico and micro hydropower plants had encountered and it attempts to identify issues related to their performances. The study was based on personal experience, field visits, participant observations, interviews and focus group discussions with key members of the beneficiary communities and documentations from the local NGO which implemented the schemes. Key findings of this study relate to the description of the main aspects about: planning of a robust system design, organizational aspects, like social cohesion at all levels of scheme management, community leadership and ownership of the system and involvement of the beneficiaries at all stages of the project cycle. These aspects were particularly addressed within the context of rural communities in Cameroon. [ABSTRACT FROM AUTHOR]

Integrated systems modelling has provided insights on pathways for the sustainable use of energy, land and water resources. Among the existing modelling tools, some have been widely used to engage policy makers, due to their open source and basic structure. Yet, in the attempt of simplifying the representation of integrated systems, essential features significantly influencing the dynamics between systems may have been left aside. This study proposes an improved formulation of the Open Source Energy Modelling System (OSeMOSYS), for a better representation of energy and resource storage processes. In particular, the focus of this work is the storage losses introduction for both dams for hydropower generation and batteries for electricity storage. The modifications were applied to a case study representing key features of both a developed and developing country. The results highlight that, with low additional computational effort, a much more accurate representation of the storage technologies can be achieved. Despite the introduction of losses, renewable energy technologies tend to have a high penetration in the future energy mix thanks to storage applications that remedy their unpredictability and seasonality. • An improved storage formulation in the OSeMOSYS modelling framework is proposed. • Storage losses for water dams and batteries have been implemented in OSeMOSYS. • The improved formulation has been tested and verified through the Atlantis case study. • An accurate storage representation can be performed with few computational effort. [ABSTRACT FROM AUTHOR]