Renewable and Sustainable Energy Transition最新文献

Energy scenarios are often claimed to support decision-makers involved in the energy transition. However, an empirical understanding of how decision makers select, interpret, and use energy scenarios is largely missing. This study examined how high-level public utility executives in the energy sector, a key target audience of energy scenarios, perceive and interact with energy scenarios. Based on interviews with representatives of 20 Swiss utilities, we show that the use of scenarios is rarely part of a formalized process aimed at assisting decision-making processes. Instead, the selection of scenarios is often contingent on users’ perceptions of their legitimacy, credibility, and salience. While utility executives could rely on a wide variety of scenarios published by academic, corporate, and non-governmental organizations, they often focus on a limited set. Given the complexity of contemporary energy scenarios, which are often based on sophisticated energy system models, familiarity with publishing organizations and reporting styles is an important selection heuristic for users. This stands in contrast to the purpose and of stated key motivation of considering a broad range of plausible futures and their associated trade-offs. Our results suggest that to evaluate the impact of energy scenarios, social-scientific research also needs to consider user groups that are neither involved in participative modeling activities, nor collaborating with scenario developers in any other form. The usefulness of energy scenarios in these contexts and particularly their capacity to contribute to integrative deliberations on plausible and desirable energy futures is highly relevant, yet largely unknown.

The extent to which modelled future pathways support effective policymaking for sustainability transitions has been questioned for a long time, with one major issue being the insufficient integration with the perspectives of policymakers and other stakeholders. One proposal to address this issue has been to set up facilitative dialogues with stakeholders to extend model-based pathways to socio-technical scenarios. This paper presents the results of a first series of such co-creation workshops, where stakeholders discussed bottlenecks for model-based decarbonisation pathways and ways to overcome these bottlenecks through tailored policy mixes. The workshops took place in five countries: Brazil, Canada, Greece, Germany, and the UK, each with a specific sector focus. In all five workshops, it became clear that substantial tensions exist between the “ideal” modelled decarbonisation pathways and the real-world situation on the ground. Also, adverse political framework conditions, uncertainty of future policies and resistance of powerful actors were emphasised as overarching bottlenecks in most workshops. At the same time, in several instances stakeholders pointed out important aspects of transformative trajectories that are not covered by the models. Some challenges and solutions stand out in all countries in spite of the strong diversity of contexts: allocation of capital towards massive investments into low-carbon solutions; infrastructure development for generation and transport of hydrogen, capture and use of CO₂ as well as electricity grid and storage adapted to renewable energy solutions; stakeholder and citizen dialogues, where agreement is reached on cornerstones of long-term decarbonisation trajectories; and demand-side measures complementing investments into low-carbon processes.

Canada has pledged ambitious emission targets, aiming to achieve a reduction of at least 40–45% below 2005 levels by 2030 and net-zero emissions by 2050. Being amongst the major economies with high dependence on fossil fuels, however, this path is far from straightforward. This research employs NATEM, a TIMES-based regional energy system model for North America with explicit representation of Canada, as well as knowledge produced and shared by stakeholders during a targeted workshop dedicated to identifying decarbonisation bottlenecks, to compare the paths to net zero on the basis of whether stakeholder perceptions are considered or not. We find that the path to net-zero is technically feasible but critically entails the use of negative emissions technologies, like (bioenergy with) carbon capture and storage (CCS) and direct air capture, in addition to the large-scale deployment of a large range of mitigation options already available today. Based on the feedback received from the stakeholders, around both the use of CCS-based technologies and the potential of demand-side measures such as modal shifts in transportation and better urban planning, we impose a set of additional conditions and restrictions. We find that the co-created net-zero pathway is also technically feasible while relying less on technologies that may trigger bottlenecks prioritised by the stakeholders; notably, despite yielding a similar emissions trajectory, it entails significantly different sectoral and technological configurations to the non-co-created net-zero scenario, requiring an acceleration of near-term abatement measures, mainly through electrification and quicker rollout of renewable and other clean energy technologies.

It is hard to assess the pace and prospects of the solar revolution and the just energy transition. In architecture solar energy continues to be seen as a salve, a convenient and effective response to the forces – social, regulatory, economic – pushing for more and more efficient energy use in buildings. Photovoltaics solve everyone's problem: the building's form and program do not change dramatically, the renewable industry is furthered in its boom, savings in energy bills follow. Occupancy of the building goes on more or less as before.

Yet the application of solar panels to a building, not to mention the prospect for more and more expansive solar farms, reproduces the extractive model of fossil fuels. Rare earth materials need to be mined and shipped. The manufacturing process is toxic. The beneficiaries tend to be those who can already afford to save and conserve. The clean are getting cleaner, while those struggling with energy supply are less frequently benefited. The panels need to be replaced relatively frequently, yoking economies to resource dependencies sure to be exacerbated as electricity demand swells. Amidst the broad discourse around the just energy transition, photovoltaic solar energy is itself most likely transitional, contingent and conditional.

The analysis of architecture provides a few windows on to the nuances and challenges of this next phase of the just energy transition – on how we can collectively think differently around resources and their provision in our buildings, as a site for both collectivization and social transformation.

Universal access to clean electricity (SDG7) in remote areas of the rural South remains a key challenge for economic growth, and has particular implications for equitable, inclusive and sustainable development. In Pakistan, techno-economic constraints in grid expansion for last-mile users, combined with the country's high solar energy potential make off-grid solar energy generation a viable solution, provided its technological, social and economic implications are well-understood in terms of actual energy demands and designed for equitable distribution. This paper presents a socio-technical feasibility assessment for designing equitable and inclusive off-grid solar systems using the case-study of Helario village in Tharparkar, Pakistan, with a key focus on gender-specific benefits. A mixed-methods approach is used to conduct a baseline field assessment of existing energy sources, community needs, women's access and energy use, affordability, future energy aspirations and social acceptability of renewable energy technologies. Results indicate gendered differences in mobility, education, everyday practices and income that have socio-economic implications, whereby women can benefit more from electrification, particularly when electricity is interlinked with access to clean water. Results are used to model, simulate and optimise a solar-battery mini-grid system for tiered and equitable energy access using CLOVER. Analysis shows that a system designed with a 10-year lifetime provides the lowest levelised cost of electricity and minimum emissions intensity, emphasising the need for long-term energy system planning. This paper serves as a demonstration for policymakers, project developers and rural communities for designing more equitable and inclusive energy systems with clear gendered implications for sustainable future access.

The paper provides energy system-wide estimates of the potential and impacts of final energy demand reductions based on behavioral changes in different sectors. Behavioral changes are for example adjusting thermostats or replacing business flights with telemeetings. By reducing demand, behavioral changes are a potentially decisive but seldomly considered factor to support the transformation towards a decarbonized energy system. Therefore, this paper addresses the following question: What is the potential of behavioral changes and what are the impacts on the supply side of a 100% renewable energy system? For this purpose, an extensive literature review is conducted to obtain estimates for the effects of different behavioral changes on final energy demand in Germany. The impact of these changes on the supply side and system costs is quantified using a bottom-up planning model of a renewable energy system. Results indicate that final energy could be reduced by up to 20.5% and as a result, renewable capacity reductions between 13.6% to 30.6% are conceivable. The greatest potential for behavioral changes was identified in the heating sector.

The ambition to reach climate-neutral energy systems requires profound energy transitions. Various scenario studies exist which present different options to reach that goal. In this paper, key strategies for the transition to climate neutrality in Germany are identified through a meta-analysis of published studies, including scenarios which achieve at least a 95 % greenhouse gas emissions reduction by 2050 compared to 1990. Reduction in energy demand, an expansion of domestic wind and solar energy, increased use of biomass as well as the importation of synthetic energy carriers are key strategies in the scenarios, with nuclear energy playing no role, and carbon capture and storage playing a very limited role. Demand-side solutions that reduce the energy demand have a very high potential to diminish the significant challenges of other strategies, which are all facing certain limitations regarding their potential. The level and type of demand reductions differ significantly within the scenarios, especially regarding the options of reducing energy service demand.

Battery-electric vehicles provide a pathway to decarbonize heavy-duty trucking, but the market for heavy-duty battery-electric semi-trailer trucks is nascent, and specific charging requirements remain uncertain. We leverage large-scale vehicle telematics data (>205 million miles of driving) to estimate the charging behaviors and infrastructure requirements for U.S. battery-electric semi-trailer trucks within three operating segments: local, regional, and long-haul. We model two types of charging—mid-shift (fast) and off-shift (slow)—and show that off-shift charging at speeds compatible with current light-duty charging infrastructure (i.e., ≤350 kW) can supply 35 to 77% of total energy demand for local and regional trucks with ≥300-mile range. Megawatt-level speeds are required for mid-shift charging, which make up 44 to 57% of energy demand for long-haul trucks with ≥500-mile range. However, demand shifts from mid-shift to off-shift charging as the range for battery-electric trucks increases and when off-shift charging is widely available. Finally, we observe geographic trends in charging demand, finding that local trucks have greater demand within urban areas, whereas long-haul trucks have more demand along rural interstate corridors. As the range for battery-electric trucks increases, we show that charging demand shifts from rural to urban locations due to observed vehicle dwell tendencies.

In line with the Dutch Climate Agreement, multiple energy transition scenarios have been constructed for 2030 and 2050. To various extents, they project a shift towards decentralized and intermittent renewable electricity generation (wind and solar) and widespread deployment of electric vehicles and heat pumps. These developments impose challenges regarding electricity supply-demand mismatch and grid congestion. In order to gain an understanding of when and where such problems are likely to occur, temporally and spatially resolved interpretations of the energy transition scenarios are required. This paper focuses on Dutch wind energy supply and shows construction of geodatabases of scenario-specific, hourly onshore and offshore wind electricity generation profiles on an individual turbine level. For the geographical distribution of turbine capacity, datasets on historically operational turbines, planned wind parks and suggested future turbine distributions are utilized. Turbine electricity generation profiles are constructed using a high resolution 3D meteorological dataset and power curves of commercially available turbine models. They are corrected for air pressure deviations and a multitude of loss factors, including wake effects. Compared to the present-day situation, yearly country-level electricity generation is projected to be a factor 16.6, 24.6 or 12.8 higher in 2050 when following the Regional, National or International Steering scenarios, respectively. In comparison to both the present-day and 2030 situation, onshore electricity generation is projected to be more evenly spread over different parts of the country in 2050. All offshore wind exploration areas considered in this research are projected to be completely utilized by 2050.

The global transport sector is the second largest energy consumer and strongly relies on fossil fuels. Efforts for reducing GHG emissions on this sector depend on energy efficiency improvement and the use of renewable fuels and electrification. All these technologies are commercially available and each one faces some barriers to overcame environmental and financial issues. Complete vehicle electrification is still expensive, and its use as an environmentally sound solution relies on decarbonization of the electricity supply. Vehicles equipped with internal combustion engines running on renewable liquid fuels are less expensive than battery electric vehicles but its energy intensity by land area (MJ/ha) is low. We have examined an alternative where both solutions are combined through the deployment of Plug -in Hybrid Vehicles, using renewable fuel and renewable electricity. Selecting sugar cane as a source of ethanol, we can take advantage of its coproduct – electricity, used for battery charging. We have determined the well to wheel lifecycle carbon balance of PHEV consuming sugarcane-based electricity and ethanol for several scenarios being the lowest one 67gCO2e/mile. We have demonstrated that this technology is a viable alternative for climate mitigation goals. Based on published forecasts for efficiency improvements, on existing vehicle and fuel production pathways, we have shown that a car fleet of one billion units in operation by 2030 can be fueled through harvesting 125.2 million hectares of land with sugar cane and eucalyptus. Considering that ethanol and gasoline have the same performance, on miles per gallon based on their respective energy content, the total harvested area decreases to 103.7 Mha.