Renewable and Sustainable Energy Transition最新文献

We arrive at an auspicious inflection point in the proliferation of solar photovoltaic systems. Apprised of particular and patterned racial and gendered solar injustices across disparate energy geographies, scholars and practitioners must harness solar power in the service of the total abolition of racial power structures that enshrine inequalities in colonial-capitalist accumulation. Antiracist and anticapitalist approaches to solar interventions can potentially transform social relations and empower the victims of energy injustices. Abolition solarities avail emancipation and redistribution through dismantling white supremacist processes and logics that structure energy regimes. How can solar simultaneously stitch translocal and transnational nets of safety and solidarity among subaltern architects and inheritors of abolition democracy? Aspiring to the existential obligation to change everything, let us wire solar to elucidate emancipation.

The fast deployment of renewable energy in Italy by 2030, according to the National Energy and Climate Plan, will lead to renewable electricity surplus mainly in Southern Italy where adequate energy storage is not currently available. In this paper, a Power to Green Hydrogen followed by a methanation process is proposed to accelerate decarbonisation and the integration of higher shares of variable renewable energies in Southern Italy. Green hydrogen can be injected directly into the natural gas grid or used to produce biomethane that can be injected afterwards into the natural gas grid. The main results of our assessment are: 1) 819 – 1,638 Mm³ green hydrogen that could be produced by water electrolysis using the renewable electricity surplus; 2) 160 Mm³ biomethane produced through biogas upgrading and 3) 14 – 117 Mm³ additional biomethane produced through methanation by using biogenic carbon dioxide from biogas upgrading. The approach would enable a) green hydrogen production cost competitive with grey hydrogen (44 €/MWh) only when the electrolysis system uses electricity for free and its load factor is above 1,800 h/y and 5,000 h/y for the optimistic and conservative case, respectively; b) biomethane production cost via biogas upgrading (about 58 €₂₀₂₀/MWh); and c) biomethane production cost via methanation competitive versus natural gas price (30 €/MWh) only when using electricity for free and operates at full load for over 5,400 h/y in the optimistic case.

The transition to a low-carbon energy future requires large amounts of many raw materials. Some of these materials are deemed critical in terms of their limited availability, concentrated supply chain networks, associated environmental impact, and various social issues. Acknowledging the significant dependency on raw materials for future energy scenarios, this paper presents a systematic review of the existing literature to identify the barriers, solutions proposed and the current research gaps associated with the supply of a range of critical chemical elements. The focus was mainly on evaluating supply risk in light of raw material availability and contemporary extraction technologies. Results indicate that a transition to a low-carbon energy system is possible, but will require efforts to address supply concerns, and strategic planning. A key risk mitigation strategy is increasing material circularity, especially to cope with the growth in demand for cobalt in lithium-ion batteries, platinum used in fuel cells and electrolysers, iridium used in electrolysers and dysprosium used in permanent magnets. Copper was found to be possibly the most concerning critical element due to the expected demand from developing nations in addition to the demand for the energy transition. The geopolitical, social, and environmental risks for lithium, cobalt, rare earth elements and platinum group metals could also hinder future energy security, as demand for these elements continues to grow.

Deep decarbonisation pathways can enable the state of New South Wales (NSW) in Australia to reach a net-zero emissions reduction goal and contribute to global mitigation efforts to limit temperature rise to 1.5 °C by mid-century. This paper explores minimum cost solutions for achieving the corresponding greenhouse gas (GHG) emissions reduction target for NSW, using an Australian implementation of the TIMES (The Integrated MARKAL-EFOM System) energy system modelling framework. This paper investigated possible decarbonisation pathways and available technology options to reach the target. It includes both a higher emissions reference case scenario and a scenario implementing the NSW state government's target of net-zero emissions by 2050 under the NSW Climate Change Policy Framework, consistent with the international Paris Agreement on climate change, with available and viable well-developed technologies. The findings show that the NSW energy system can continue its shift from fossil fuels to renewables like solar, wind, and hydro and can entirely phase out coal- and gas-fired electricity generation by 2050. The deployment of zero-emissions technologies along with policy supports are crucial to achieving deep decarbonisation of the NSW economy by 2050. In addition, electrification and energy efficiency improvements play a significant role in the end-use sector's energy consumption reduction in the coming decades. This paper shows that the electricity sector is the dominant contributor to emission reductions up to the year 2030, while transport, buildings, and industry sectors are set to decarbonise later in the projection period (2030–2050) along this least-cost trajectory. However, the NSW government's aspirational target of net-zero emissions by 2050 can be achieved by 2039 by offsetting negative emissions.

Access to reliable and sustainable electricity is still precluded for a large share of global population living in rural areas of developing countries, especially in sub-Saharan Africa. Hybrid microgrids are considered a suitable solution for providing affordable and reliable access to electricity to isolated communities. Properly planning and sizing such systems is although an aspect that can greatly influence the sustainability of the intervention, and the arrival to the market of the third generation minigrids poses new challenges to the process. Three main challenges are identified as pivotal for the proper sizing of new generation microgrids: arrival of the main grid, inappropriateness of Net Present Cost as only objective function in the strategy selection process, and necessity to operate on already existing minigrids. Such aspects are addressed in this work by proposing a methodological advancement to an existing open-source microgrid sizing model: a grid outage model alongside the definition of new constraints and variables for the optimization problem with grid-connected microgrids, a multi-objective optimization option, and a brown-field optimization option. The new version of the model is tested on real life case studies in rural Rwanda (greenfield) and Mozambique (brownfield), proving the profitability of grid-connected and grid-extension solutions for sufficiently low connection distances. Sensitivity analyses are performed to assess variations in system size, cost and CO₂ emissions with respect to microgrid and grid connection parameters.

By 2025, Senegal's energy mix will have shifted from one reliant on heavy fuel oil to one consisting primarily of solar and wind energy as well as liquefied natural gas. The expectation is that this will lead to lower greenhouse gas emissions, more affordable power, and broad-based growth and development. Despite the necessity of a transition to renewable energy, scholarship in critical energy geographies has cautioned that such a transition could (re)produce socio-environmental injustices. Yet only a relatively small (but growing) number of studies in the political ecology of renewable energy literature examines how energy transitions are framed and justified as part of national-level narratives in the global South. Understanding this is critical because framing (renewable) energy in relation to national development objectives is a strategy central to the material development of renewable energy projects. Through a case study of Senegal, this paper examines the national-level discourses that underlie the country's turn towards utility-scale renewable energy by analyzing key documents and institutional interviews (carried out between 2018 and 2020). Findings show that a dominant group of development actors along with state institutions mobilizes a “grand narrative” on economic growth and poverty reduction vis a vis renewable energy development to facilitate a shift to renewables that rests on market logics, with questionable implications for equity and justice. The paper reflects on the implications of this narrative for the potential of a just energy transition in Senegal, as well as the broader theoretical and empirical implications of the research.

The region of the Eastern Mediterranean and Middle East (EMME) is one with highly diverse socioeconomic conditions. It is split between countries with rich fossil fuel reserves, which are net energy exporters, and countries that rely to a large extent on energy imports to satisfy their domestic demand. Despite the abundant renewable energy resources, especially for wind and solar, in 2019 renewable energy accounted for merely 12% of the total electricity generation across the region. The present effort aims to highlight the potential benefits offered by a future enhancement in electricity trade between EMME countries; this could unlock the currently unexploited renewable energy resources of the region. A model representing the national electricity supply system of seventeen EMME countries is developed in a cost-optimisation modelling framework (OSeMOSYS). This is then used to project cost-optimal development pathways for the respective energy systems, by assessing alternative scenarios where regional trade is limited or enhanced. Comparison of a set of scenarios is conducted to quantify implications in terms of renewable energy deployment, greenhouse gas emissions and overall system costs. Results from the analysis indicate that in the absence of climate neutrality ambition across the region, electricity trade is limited to existing levels. However, the need for electricity trade increases when countries strive to decarbonise their electricity supply cost-effectively.

District heating can help to integrate renewable generation within the electricity domain and thus reach climate and energy goals by providing flexibility services and stabilizing the electricity grid. To determine the economic viability of such flexibility services, this work presents a profitability analysis of a central heat pump and/or combined heat and power unit within a biomass-based district heating network, conducted with a mixed-integer linear optimization model. Subsequent business model development for district heating utilities is conducted using the Business Model Canvas and the Odyssey 3.14 approach. Business model development and innovation are crucial to make use of the existing flexibility potential. The results show that the district heating utility's profitability as annual net profit increases in comparison with the status quo of biomass heat-only boilers when an additional heat pump is installed that can operate both in spot and balancing markets. Furthermore, all use cases including governmental support (for the heat pump, the combined heat and power unit or for both) prove to be economically favorable. The innovated business models indicate additional value for increased customer segments, thus enabling additional revenue streams for the district heating utility which can therefore promote the provision of flexibility in district heating.

For its abundant fossil resources, the Central Asia and Caspian region plays a strategic role in the energy security of major markets, such as Europe and China. However, this dependence on export, added to a firm reliance on fossil fuels for internal consumption, represents a significant challenge for the decarbonisation of the region.

In this paper, we perform an energy scenario analysis of four countries in the region (Azerbaijan, Kazakhstan, Uzbekistan and Turkmenistan), aiming to investigate how ambitious their regional decarbonisation targets for 2050 are in view of the Paris Agreement. We also develop a net-zero emission pathway to reinforce the regional climate ambition in the long term. As a novelty in the literature, the scenario analysis is co-designed with regional stakeholders through an engagement process that we have carried out from December 2020 to May 2021.

The analysis is performed with the TIMES-CAC energy system model. Results show that current regional energy policies are insufficient for achieving ambitious climate targets in the long term (2050 and beyond). The lack of a long-term strategy to decrease the dependence on export increases the influence of importing countries’ energy policies. Even in a decarbonised scenario, the role of China remains significant, while the dependence on the European Union decreases. To limit the pressure from other countries in the energy transition, the region should start implementing a rigorous energy planning process today to fill the “ambition gap” and achieve carbon neutrality in a 40-year horizon.

Transportation electrification is viewed as one way for governments to realize their commitment to transition away from fossil fuel use in pursuit of addressing environmental, energy, and security concerns. In this paper, we examine pathways that different American cities with varying degrees of plug-in electric vehicle (PEV) adoption and policy activity took to encourage PEV adoption in the late 2010s. Our research entails a comparative case study of eight U.S. cities. We rely on secondary data for these cities to identify PEV adoption and policy activity, and data from semi-structured interviews with 38 PEV stakeholders to understand how individual, policy, social, and infrastructural factors informed transportation electrification. Among our key findings is that transportation electrification in cities was streamlined through the work of PEV advocates that collaborated across sectors on a variety of projects. In addition to addressing the nuances of this diverse stakeholder collaboration, this paper solicits insights from these on-the-ground stakeholders on topics related to the pursuit of complementary but distinct policy activities at the state and local levels, and the importance of policy in encouraging PEV adoption.