26 research outputs found
Energy projections for African countries
This report provides insights on energy supply and demand, power generation, investments and total system costs, water consumption and withdrawal by the energy sector as well as carbon dioxide emissions for the African continent.
The energy supply systems of forty-seven African countries are modelled individually and connected via gas and electricity trade links to identify the cost-optimal solution to satisfy each country's total final energy demand for the period 2015-2065. In this analysis, The Electricity Model Base for Africa (TEMBA) was extended to include a simple representation of the full energy system. It was also updated to include new data. Simulations were run using the medium- to long-term Open Source Energy Modelling System tool (OSeMOSYS). The TEMBA model produces aggregate results for the whole continental energy system and more detailed ones for the power system of each African country.
The scenarios examined in this study consider different emission trajectories and technology availability. The Reference scenario considers the national energy policies that were in place until 2017, whereas the 2.0°C and 1.5°C scenarios examine emission levels aligned with the climate targets agreed under the United Nations Framework Convention on Climate Change (UNFCCC) Paris Agreement. The scenarios have been aligned with the "Global Energy and Climate Outlook 2018: Greenhouse gas emissions and energy balances" report of the Joint Research Centre (Keramidas et al., 2018). The results demonstrate that power generation capacity will need to increase 10-fold from 2015 to 2065 to meet projected electricity demands. A significant proportion of this capacity will likely consist of renewable energy sources, particularly under the 2.0°C and 1.5°C scenarios, as technology costs fall. On the contrary, there will only be little investment for new coal generation. In addition, a number of African countries will invest in nuclear power plants and CCS technologies (biomass, coal, gas) in the future in order to achieve the emission targets set in the 2.0°C and 1.5°C scenarios.
The results also indicate how water demand from the energy sector could evolve. Under the Reference scenario, it is estimated that by 2065 the African energy system will contribute to a water withdrawal of approximately 4% of the total renewable water resources (TRWR) in Africa (3,950 bcm) (FAO - Food and Agriculture Organization of the United Nations, n.d.). On the one hand, this share appears meagre, but in reality, this number must be analysed in the perspective of the nexus between water for food, energy, household and productive uses. Most of the thermal power infrastructure is not located in remote places and is rather near to population centres. This creates an added complexity to future infrastructure planning. On the other hand, water withdrawals are expected to decrease to 1.2% and 1.6% of TRWR in the 2.0°C and 1.5°C scenarios respectively by 2065 owing to deep decarbonisation of the energy sector.JRC.C.7-Knowledge for the Energy Unio
Climate, Land, Energy and Water systems interactions – From key concepts to model implementation with OSeMOSYS
The Climate, Land, Energy and Water systems (CLEWs) approach guides the development of integrated assessments. The approach includes an analytical component that can be performed using simple accounting methods, soft-linking tools, incorporating cross-systems considerations in sectoral models, or using one modelling tool to represent CLEW systems. This paper describes how a CLEWs quantitative analysis can be performed using one single modelling tool, the Open Source Energy Modelling System (OSeMOSYS). Although OSeMOSYS was primarily developed for energy systems analysis, the tool’s functionality and flexibility allow for its application to CLEWs. A step-by-step explanation of how climate, land, energy, and water systems can be represented with OSeMOSYS, complemented with the interpretation of sets, parameters, and variables in the OSeMOSYS code, is provided. A hypothetical case serves as the basis for developing a modelling exercise that exemplifies the building of a CLEWs model in OSeMOSYS. System-centred scenario analysis is performed with the integrated model example to illustrate its application. The analysis of results shows how integrated insights can be derived from the quantitative exercise in the form of conflicts, trade-offs, opportunities, and synergies. In addition to the modelling exercise, using the OSeMOSYS-CLEWs example in teaching, training and open science is explored to support knowledge transfer and advancement in the field
Spatial band-pass filtering aids decoding musical genres from auditory cortex 7T fMRI
Spatial filtering strategies, combined with multivariate decoding analysis of BOLD images, have been used to investigate the nature of the neural signal underlying the discriminability of brain activity patterns evoked by sensory stimulation – primarily in the visual cortex. Previous research indicates that such signals are spatially broadband in nature, and are not primarily comprised of fine-grained activation patterns. However, it is unclear whether this is a general property of the BOLD signal, or whether it is specific to the details of employed analyses and stimuli. Here we applied an analysis strategy from a previous study on decoding visual orientation from V1 to publicly available, high-resolution 7T fMRI on the response BOLD response to musical genres in primary auditory cortex. The results show that the pattern of decoding accuracies with respect to different types and levels of spatial filtering is comparable to that obtained from V1, despite considerable differences in the respective cortical circuitry
Carrying out a multi-model integrated assessment of European energy transition pathways: Challenges and benefits
With the publication of the European Green Deal, the European Union has committed to reaching carbon neutrality by 2050. The envisaged reductions of direct greenhouse gases emissions are seen as technically feasible, but if a wrong path is pursued, significant unintended impacts across borders, sectors, societies and ecosystems may follow. Without the insights gained from an impact assessment framework reaching beyond the techno-economic perspective, the pursuit of direct emission reductions may lead to counterproductive outcomes in the long run. We discuss the opportunities and challenges related to the creation and use of an integrated assessment framework built to inform the European Commission on the path to decarbonisation. The framework is peculiar in that it goes beyond existing ones in its scope, depth and cross-scale coverage, by use of numerous specialised models and case studies. We find challenges of consistency that can be overcome by linking modelling tools iteratively in some cases, harmonising modelling assumptions in others, comparing model outputs in others. We find the highest added value of the framework in additional insights it provides on the technical feasibility of decarbonisation pathways, on vulnerability aspects and on unintended environmental and health impacts on national and sub-national scale.(c) 2022 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)
Capacity development and knowledge transfer on the climate, land, water and energy nexus
Applying the concept of the nexus of climate, land, energy and water systems (CLEWs) to sustainable development requires the integration of knowledge from different disciplines to solve complicated multi-systems challenges. Such knowledge and expertise are not solely situated in scientific research’s theoretical realm (i.e. branch of knowledge). For the approach to be successful, integration is also required in a variety of decision spaces. The development of nexus knowledge, which we define as information related to systems’ physical, natural and socioeconomic interactions, broadly emerged from project-oriented research and case
study applications, extending the system’s coverage to several resource systems, climate and governance
From the development of an open-source energy modelling tool to its application and the creation of communities of practice: The example of OSeMOSYS
In the last decades, energy modelling has supported energy planning by offering insights into the dynamics between energy access, resource use, and sustainable development. Especially in recent years, there has been an attempt to strengthen the science-policy interface and increase the involvement of society in energy planning processes. This has, both in the EU and worldwide, led to the development of open-source and transparent energy modelling practices.
This paper describes the role of an open-source energy modelling tool in the energy planning process and highlights its importance for society. Specifically, it describes the existence and characteristics of the relationship between developing an open-source, freely available tool and its application, dissemination and use for policy making. Using the example of the Open Source energy Modelling System (OSeMOSYS), this work focuses on practices that were established within the community and that made the framework's development and application both relevant and scientifically grounded
From the development of an open-source energy modelling tool to its application and the creation of communities of practice: The example of OSeMOSYS.
In the last decades, energy modelling has supported energy planning by offering insights into the dynamics
between energy access, resource use, and sustainable development. Especially in recent years,
there has been an attempt to strengthen the science-policy interface and increase the involvement of
society in energy planning processes. This has, both in the EU and worldwide, led to the development of
open-source and transparent energy modelling practices.
This paper describes the role of an open-source energy modelling tool in the energy planning process
and highlights its importance for society. Specifically, it describes the existence and characteristics of the
relationship between developing an open-source, freely available tool and its application, dissemination
and use for policy making. Using the example of the Open Source energy Modelling System (OSeMOSYS),
this work focuses on practices that were established within the community and that made the framework's
development and application both relevant and scientifically grounded
The Climate, Land, Energy, and Water systems (CLEWs) framework: a retrospective of activities and advances to 2019
Population growth, urbanization and economic development drive the use of resources. Securing access to essential services such as energy, water, and food, while achieving sustainable development, require that policy and planning processes follow an integrated approach. The 'Climate-, Land-, Energy- and Water-systems' (CLEWs) framework assists the exploration of interactions between (and within) CLEW systems via quantitative means. The approach was first introduced by the International Atomic Energy Agency to conduct an integrated systems analysis of a biofuel chain. The framework assists the exploration of interactions between (and within) CLEW systems via quantitative means. Its multi-institutional application to the case of Mauritius in 2012 initiated the deployment of the framework. A vast number of completed and ongoing applications of CLEWs span different spatial and temporal scales, discussing two or more resource interactions under different political contexts. Also, the studies vary in purpose. This shapes the methods that support CLEWs-type analyses. In this paper, we detail the main steps of the CLEWs framework in perspective to its application over the years. We summarise and compare key applications, both published in the scientific literature, as working papers and reports by international organizations. We discuss differences in terms of geographic scope, purpose, interactions represented, analytical approach and stakeholder involvement. In addition, we review other assessments, which contributed to the advancement of the CLEWs framework. The paper delivers recommendations for the future development of the framework, as well as keys to success in this type of evaluations
Evaluation of absorbed and effective doses to patients from radiopharmaceuticals using the ICRP 110 reference computational phantoms and ICRP 103 formulation
International audienceIn diagnostic nuclear medicine, mean absorbed doses to patients' organs and effective doses are published for standard stylised anatomic models. To provide more realistic and detailed geometries of the human morphology, the International Commission on Radiological Protection (ICRP) has recently adopted male and female voxel phantoms to represent the reference adult. This work investigates the impact of the use of these new computational phantoms. The absorbed doses were calculated for 11 different radiopharmaceuticals currently used in diagnostic nuclear medicine. They were calculated for the ICRP 110 reference computational phantoms using the OEDIPE software and the MCNP extended Monte Carlo code. The biokinetic models were issued from ICRP Publications 53, 80 and 106. The results were then compared with published values given in these ICRP Publications. To discriminate the effect of anatomical differences on organ doses from the effect of the calculation method, the Monte Carlo calculations were repeated for the reference adult stylised phantom. The voxel effect, the influence of the use of different densities and nuclear decay data were also investigated. Effective doses were determined for the ICRP 110 adult reference computational phantom with the tissue weighting factor of ICRP Publication 60 and the tissue weighting factors of ICRP Publication 103. The calculation method and, in particular, the simulation of the electron transport have a significant influence on the calculated doses, especially, for small and walled organs. Overestimates of >200 % were observed for the urinary bladder wall of the stylised phantom compared with the computational phantoms. The unrealistic organ topology of the stylised phantom leads to important dose differences, sometimes by an order of magnitude. The effective doses calculated using the new computational phantoms and the new tissue weighting factors are globally lower than the published ones, except for some radiopharmaceuticals, where the differences can reach 60 % higher than the published values. This study analyses the first set of absorbed and effective doses with the new ICRP male and female reference computational phantoms for different radiopharmaceuticals. It highlights the importance of taking into account the electron transport and the realism of the shape and inter-organ distances of the anthropomorphic model used. © The Author 2013. Published by Oxford University Press. All rights reserved
Creation of ORNL NURBS-based phantoms Evaluation of the voxel effect on absorbed doses from radiopharmaceuticals
International audienceDoses from radiopharmaceuticals absorbed by organs can be assessed using Monte Carlo simulations and computational phantoms. Patient-based voxel phantoms improve the realism of organ topology but present unrealistic stair-stepped surfaces. The goal of this research was to study the voxel effect on the basis of creation and voxelisation of a series of non-uniform rational B-spline (NURBS) reference phantoms issued from the publication of the Oak Ridge National Laboratory (ORNL). Absorbed doses from various radiopharmaceuticals were calculated and compared with the values obtained for the corresponding analytical phantoms for models of an adult male and a 5-y-old child. Dose differences lower than 12.5% were observed when the critical structure of the skin was excluded. Moreover, the highest differences were noted for small organs and walls. Finally, all NURBS phantoms of the ORNL series, their voxelised version and the corresponding Monte Carlo N-Particle eXtended input files were programmed and are available for further simulations. © The Author 2012. Published by Oxford University Press. All rights reserved