Energy and climate change最新文献

Achieving global climate targets requires massive reductions in greenhouse gas emissions from energy-intensive industrial sectors. We investigate whether financing is an important obstacle for radical emission reduction in industry. We study Sweden as a case of a country that is comparatively advanced in its planning for transitions to low-carbon industrial production. We find that the size of capital investments or the availability of financing for these investments is not perceived as a significant obstacle. There are a number of factors explaining this, such as the fact that the companies involved in this study are well-established, large corporates, and hence well placed to finance their transition plans through conventional corporate finance channels, that conditions for market demand are good in the EU, and that many of the firms are in early stages of developing new technologies, when capital need is smaller compared to later stages. We also find that many financial actors express a strong appetite for sustainable investments. Finally, we observe that despite financing not being perceived as an obstacle, there is still a large and important role to play for public actors for reducing the risk of investments and accelerating the pace of change going forward.

This study focused on developing a comprehensive model to perform techno-economic analysis and calculate greenhouse gas emissions and net energy balance of cassava-based ethanol production in Vietnam. Four steps were involved in this study: (1) collecting data on the cassava-based ethanol conversion pathway, (2) modeling an ethanol production plant, (3) calculating greenhouse gas emissions and net energy balance, and (4) evaluating economic feasibility. The total capital investment and production cost per liter of ethanol are 0.6 $/l/yr and 0.4 $/l, respectively. The fossil energy consumption and net energy ratio during cultivation, transportation, production, and use of ethanol are 12.4 MJ/l and 1.70, respectively. The total greenhouse gas emissions of cassava-based ethanol production are 1252 gCO₂eq/l or 59.1 g_CO2eq/MJ, which equals 63 % of greenhouse gas emissions from gasoline. This finding confirms that cassava-based ethanol can be an alternative fuel based on economic feasibility and environmental benefit by reducing greenhouse gas emissions in Vietnam.

Solar energy technologies are emerging as strong alternatives to their fossil fuel-based conventional counterparts for various applications. Solar water heating system (SWHS) is one of the most adopted technologies all over the world. Moreover, the building sector consumes significant energy from fossil fuels worldwide to meet hot water demand. This fossil fuel consumption can be reduced with the surplus economic and environmental benefits through the refurbishment of SWHSs in residential buildings. Additionally, the student hostels of academic institutes/Universities have great potential to save energy, environment, and money. In view of the same, the technical, economic, and environmental analyses of refurbishing SWHS in the student hostel are presented in the present paper. The analysis is carried out for the hostel named ‘Raman’ of DIT University, located in Dehradun, India. The energy-saving potentials of flat plate collector (FPC)-based and evacuated tube collector (ETC)-based SWHSs to accomplish the hot water demand of selected site are assessed in comparison with electric geyser. Moreover, the economic analysis is also reported in terms of net present value and benefit-to-cost analysis. Whereas the environmental benefit is presented in terms of reduction in equivalent CO₂ emissions through implementing both types of considered SWHSs. It is found that the FPC-based and ETC-based SWHSs can fulfil 60.9 % and 67.6 % of the energy demand to heat the required water. Whereas, both of the systems are found economically as well as environmentally beneficial and ETC-based SWHS is recommended for the selected site. The present study may be useful for the energy planning and management of student hostels under academic institutes/Universities.

This study investigates the impact of climate change mitigation technologies, specifically agricultural land management and renewable energy consumption and production, on greenhouse gas emissions (GHG) in sub-Saharan Africa (SSA) over the period of 1991 to 2015. Our analysis was conducted using an ARDL panel data model with data from 26 countries representing four sub-regions. The results demonstrated that an increase in renewable energy consumption is significantly associated with a decrease in GHG emissions, with a long-term coefficient of -0.422 and a short-term coefficient of -0.757. Additionally, natural resource rents, agricultural land use and population density have a positive impact on greenhouse gas emissions, with coefficients of 0.0605, 0.392 and 0.690, respectively. However, renewable energy production does not have a significant effect on greenhouse gas emissions. This suggests that promoting renewable energy consumption can be an effective way to combat greenhouse gas emissions in the region, and policymakers should implement policies and programs that encourage and facilitate the adoption of renewable energy whilst taking into consideration the impact of agricultural land use. Overall, this study emphasizes the importance of promoting renewable energy consumption and managing agricultural land use as a viable approach to combating greenhouse gas emissions in sub-Saharan Africa, and highlights the potential of climate mitigation technology as a tool for regulators to optimize policy development and counter climate change.

Green hydrogen is expected to play a vital role in decarbonizing the energy system in Europe. However, large-scale deployment of green hydrogen has associated potential trade-offs in terms of climate and other environmental impacts. This study aims to shed light on a comprehensive sustainability assessment of this large-scale green hydrogen deployment based on the EMPIRE energy system modeling, compared with other decarbonization paths. Process-based Life Cycle Assessment (LCA) is applied and connected with the output of the energy system model, revealing 45% extra climate impact caused by the dedicated 50% extra renewable infrastructure to deliver green hydrogen for the demand in the sectors of industry and transport in Europe towards 2050. Whereas, the analysis shows that green hydrogen eventually wins on the climate impact within four designed scenarios (with green hydrogen, with blue hydrogen, without green hydrogen, and baseline), mainly compensated by its clean usage and renewable electricity supply. On the other hand, green hydrogen has a lower performance in other environmental impacts including human toxicity, ecotoxicity, mineral use, land use, and water depletion. Furthermore, a monetary valuation of Life Cycle Impact (LCI) is estimated to aggregate 13 categories of environmental impacts between different technologies. Results indicate that the total monetized LCI cost of green hydrogen production is relatively lower than that of blue hydrogen. In overview, a large-scale green hydrogen deployment potentially shifts the environmental pressure from climate and fossil resource use to human health, mineral resource use, and ecosystem damage due to its higher material consumption of the infrastructure.

Climate change is one of the most critical issues in the last decade, making investigating climate change risks' effects on the economy vital. Employing a novel time-varying Granger causality approach, we test causality from climate policy uncertainty (CPU) to the index returns of clean energy and nonrenewable energy sectors between November 2009 and December 2021. Our analysis generally reveals a significant causality from CPU to S&P clean energy sector index return throughout the sample period. In contrast, very limited significant causality is observed running from the CPU to the S&P nonrenewable energy index return. This result implies that investments in clean energy firms are affected by the CPU due to the cost of reversing the decisions in uncertain environments. On the other hand, the U.S. newspaper media coverage of climate change has a significant impact not only on the clean energy index returns but also on non-renewable energy index returns, implying an increase in the media coverage regarding climate change influences the awareness of investors on climate change, which affects their trading strategies.

As the availability of weather-dependent, zero marginal cost resources such as wind and solar power increases, a variety of flexible electricity loads, or ‘demand sinks’, could be deployed to use intermittently available low-cost electricity to produce valuable outputs. This study provides a general framework to evaluate any potential demand sink technology and understand its viability to be deployed cost-effectively in low-carbon power systems. We use an electricity system optimization model to assess 98 discrete combinations of capital costs and output values that collectively span the range of feasible characteristics of potential demand sink technologies. We find that candidates like hydrogen electrolysis, direct air capture, and flexible electric heating can all achieve significant installed capacity (>10% of system peak load) if lower capital costs are reached in the future. Demand sink technologies significantly increase installed wind and solar capacity while not significantly affecting battery storage, firm generating capacity, or the average cost of electricity.

Nuclear reactors and variable renewables will play a significant role in the global energy transition as providers of low carbon electricity to various end use sectors. Real time balancing of power demand and supply without modulation or curtailment is possible using electrolytic hydrogen plants and energy storage systems. The generation mix adopted and load profiles are unique to a country and this study considers the specific case of India. This work analyses the use of grid connected water electrolysers, grid scale battery storage, hydrogen storage and fuel cells as flexible loads and dispatch schemes for grid balancing. Based on postulated long term power generation scenarios for India, the minimum required system sizes for grid balancing are estimated and techno-economic uncertainties are assessed. The use of water electrolysers is prioritized to make use of excess power, while minimizing battery storage requirement. This scheme can potentially produce a substantial share of low carbon hydrogen in India for use in industrial decarbonization, thus reducing the need for additional generation infrastructure.

Europe has committed to turning climate neutral by 2050 while wider stakeholders acknowledge the need for a just low carbon transition that will alleviate any negative socio-economic impacts and leave no one behind. A key first step to this direction is to identify the regions at risk. We develop a dedicated socio-economic risk indicator which makes it possible to identify the EU regions likely to be affected the most from the transition. The indicator rests on the latest definition of the IPCC, which treats risk as the combination of Hazard, Exposure and Vulnerability. In our risk index, Hazard is described as the drop in production of fossil fuel-related sectors due to the transition risk, Exposure is the respective employment share, while Vulnerability is a composite index of socioeconomic sub-indicators that further describe Sensitivity and Adaptive Capacity of the regions. We find a wide divergence across the risk profiles of EU regions. 6 % of all EU regions are found to be at high risk, while 74 % of the regions face no risk. The 15 high-risk regions are also found to experience socioeconomic challenges prior to the low-carbon transition process, thus indicating the need for dedicated supporting policy mechanisms.

Japan has formulated a net-zero emissions target by 2050. Existing scenarios consistent with this target generally depend on carbon dioxide removal (CDR). In addition to domestic mitigation actions, the import of low-carbon energy carriers such as hydrogen and synfuels and negative emissions credits are alternative options for achieving net-zero emissions in Japan. Although the potential and costs of these actions depend on global energy system transition characteristics which can potentially be informed by the global integrated assessment models, they are not considered in current national scenario assessments. This study explores diverse options for achieving Japan's net-zero emissions target by 2050 using a national energy system model informed by international energy trade and emission credits costs estimated with a global energy system model. We found that demand-side electrification and approximately 100 Mt-CO₂ per year of CDR implementation, equivalent to approximately 10% of the current national CO₂ emissions, are essential across all net-zero emissions scenarios. Upscaling of domestically generated hydrogen-based alternative fuels and energy demand reduction can avoid further reliance on CDR. While imports of hydrogen-based energy carriers and emission credits are effective options, annual import costs exceed the current cost of fossil fuel imports. In addition, import dependency reaches approximately 50% in the scenario relying on hydrogen imports. This study highlights the importance of considering global trade when developing national net-zero emissions scenarios and describes potential new roles for global models.