記述言語：英語   掲載種別：研究論文（学術雑誌）  

The Impact of Renewable Energy Generation on the Spot Market Price in Germany: Ex-Post Analysis using Boosting Method
This study combines regression analysis with machine learning analysis to study the merit order effect of renewable energy focusing on German market, the largest market in Europe with high renewable energy penetration. The results show that electricity from wind and solar sources reduced the spot market price by 9.64 (sic)/MWh on average during the period from 2010 to 2017. Wind had a relatively stable impact across the day, ranging from 5.88 (sic)/MWh to 8.04 (sic)/MWh, while the solar energy impact varied greatly across different hours, ranging from 0.24 (sic)/MWh to 11.78 (sic)/MWh and having a stronger impact than wind during peak hours. The results also show characteristics of the interactions between renewable energy and spot market prices, including the slightly diminishing merit order effect of renewable energy at high generation volumes. Finally, a scenario-based analysis illustrates how different proportions of wind and solar energies affect the spot market price.

DOI： 10.5547/01956574.41.si1.akee

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Drivers of green bond market growth The importance of Nationally Determined Contributions to the Paris Agreement and implications for sustainability
Green bonds are increasingly being applied to finance emissions reductions, sustainable development, and other cleaner production investments conducive to reaching the 2 °C temperature target of the Paris Agreement. As their markets are relatively nascent, there is a gap in the empirical literature on the drivers of green bond market growth. To assess the impact that capital market growth drivers and Nationally Determined Contributions to the Paris Agreement have on green bond issuance volumes as indicators of market growth, this study employed a structural equation model using a panel dataset of over $300 billion in green bonds issued in 49 countries between 2007 and 2017. This is the first econometric study to demonstrate unique drivers of green bond market growth in addition to factors that similarly affect conventional bond market growth. This is also the first study to construct a normalized index of Nationally Determined Contributions robustness scores to measure their impacts on green bond market growth. Macroeconomic latent factors exerted three times the total influence exerted by institutional latent factors. Institutional effects are positive and indirect, while OECD membership impacts were small and statistically insignificant. Nationally Determined Contributions scores exerted the largest positive and statistically significant impacts among observed variables. These results suggest that Nationally Determined Contributions and other macroeconomic and institutional factors are driving growing green bond issuances that will finance climate and sustainability investments through the future. They also highlight the need for broader examinations of the determinants of green bond issuances as investment vehicles for sustainable outcomes.

DOI： 10.1016/j.jclepro.2019.118643

記述言語：英語   掲載種別：研究論文（学術雑誌）  

<jats:title>Abstract</jats:title>
<jats:p>The Paris Agreement under the United Nations Framework Convention on Climate Change and the Sustainable Development Goals (SDGs) of the United Nations Development Programme both entail substantial global investments through cost-efficient, long-term financing. Noted for their risk-alleviating features and appeal to institutional and socially responsible investors, green bonds are gaining prominence in climate change and sustainable development finance frameworks. This study is the first to thoroughly examine publicly reported green bond proceeds allocations from 53 organizations to projects and assets throughout 96 countries from 2008 to 2017. Green bond markets are growing rapidly, and yearly proceeds allocation trends reveal increasing disbursements to renewable energy, clean water, low-carbon transportation, and other Paris Agreement and SDG-related investment categories. Circle plot analysis reveals unique allocation trends to specific green sectors at both regional and national levels. International finance institutions allocated the largest share of proceeds by both frequency and volume, and the projects and assets financed with green bonds in this study sample are associated with over 108 million tonnes of carbon dioxide equivalent (tCO<jats:sub>2</jats:sub>e) in greenhouse gas emissions reductions and over 1500 gigawatts in renewable energy capacity. The study concludes with suggestions for improving green bond post-issuance reporting and provides insights for future green bond applications in expanding Paris and SDG agendas.</jats:p>

DOI： 10.1088/1748-9326/ab1118

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Still a lot of Indonesia's population lacks access to electricity, and a large number of those people live in remote areas or on islands. Traditionally, electrification of areas not yet connected to the main electricity grid and too remote for grid extension has mainly been achieved through installation of decentralized generation units with diesel generators. However, with decreased cost of renewable energy technologies, renewable hybrid mini-grid systems are becoming economically viable options in an ever-increasing number of places. This paper analyzes the economic viability of renewable hybrid mini-grid systems with solar Photo-Voltaic cells, batteries, and diesel generators in a typical un-electrified village in Indonesia employing local data. The analysis is conducted by utilizing HOMER simulation techniques to design the optimal renewable hybrid mini-grid systems and the economic viability assessment of the system is performed by comparing the levelized cost of energy of the system with that of the conventional diesel system under different financial scenarios. Further financial analyses, such as Internal Rate of Return and Net Present Value, are performed for the hybrid systems to investigate what kind of financial scenarios (debt/equity ratios) and public aid (international aid and government fund), would make the hybrid systems attractive to private investors. The analysis has clarified that even at the most conservative scenario with 100&#37; equity finance, the levelized cost of energy of the renewable hybrid mini-grid system is lower than that of the diesel system. Further analysis has shown that grant finance that covers 35&#37; of the total project cost could make the hybrid system a profitable investment project for private investors even in the most conservative scenario. The paper also demonstrates that the profitability of renewable hybrid mini-grid systems is highly affected by financial scenarios (debt/equity ratios) in comparison with that of diesel systems, concluding with policy recommendations.

DOI： 10.3934/GF.2019.2.139

記述言語：英語   掲載種別：研究論文（学術雑誌）  

The adoption of renewable energy technologies in developing nations is recognized to have positive environmental impacts; however, what are their effects on the electricity supply chain workers? This article provides a quantitative analysis on this question through a relatively new framework called social life cycle assessment, taking Malaysia as a case example. Impact assessments by the authors show that electricity from renewables has greater adverse impacts on supply chain workers than the conventional electricity mix: Electricity production with biomass requires 127&#37; longer labor hours per unit-electricity under the risk of human rights violations, while the solar photovoltaic requires 95&#37; longer labor hours per unit-electricity. However, our assessment also indicates that renewables have less impacts per dollar-spent. In fact, the impact of solar photovoltaic would be 60&#37; less than the conventional mix when it attains grid parity. The answer of "are renewables as friendly to humans as to the environment?" is "not-yet, but eventually".

DOI： 10.3390/su11051370

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Relative significance of determinants of foreign direct investment in wind and solar energy in developing countries – AHP analysis
The importance of foreign direct investment (FDI) for the development of renewable energy in developing countries has been increasingly recognized. Numerous countries have created various measures to attract FDI in the renewable energy sector. This paper uses the analytical hierarch process to clarify the relative significance of the determinants in the location decisions of foreign wind and solar energy investors. A total of 18 determinants that are categorized into the macroeconomic environment, institutional environment, natural conditions, and renewable energy policy categories are used for the analysis. The results show that adding to the traditional determinants of FDI, including the macroeconomic environment, the institutional environment, and natural conditions, renewable energy support policies have the same or stronger influence as location determinants of FDI. The paper also points out that some of the traditional determinants, such as exchange rate volatility, access to land, and an efficient and transparent administrative procedure, are also very important as determinants of FDI in wind and solar energy. Policy implications focus on the determinants of FDI in wind and solar energy. The relative significance of the determinants clarified through this study offers criteria for prioritizing policies and actions for policy makers.

DOI： 10.1016/j.enpol.2018.08.055

記述言語：英語  

記述言語：英語  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Investors' perspective on determinants of foreign direct investment in wind and solar energy in developing economies - Review and expert opinions
Foreign direct investment (FDI) in renewable energy projects in 2015 has reached more than 10&#37; of the total green-field FDI worldwide, and developing economies were increasingly at the forefront of these investments. However, there are few studies that focus on the FDI in this emerging sector. Understanding determinants behind the location decisions of the FDI would lead to creating a better investment climate and further facilitate worldwide deployment of renewable energy technologies. Thus, this paper identifies the determinants of FDI in wind and solar energy in developing economies based on a literature review and semi-structured interviews. Factors that are identified through the literature review are categorized into the following categories: institutional environment, macroeconomic environment, natural conditions, and renewable energy policies. Semi-structured interviews were conducted with experts from multinational corporations that are active in FDI in wind and solar energy. Based on these interviews, 18 factors that could be considered as important determinants are selected and presented along with expert opinions. The experts' opinions suggest strong importance of renewable energy policies when compared to traditionally argued determinants of FDI including macroeconomic environment, institutional environment and natural conditions. Among traditionally argued determinants, exchange rate stability is suggested to be one of the most important factors considering the positioning of investments in solar and wind energy in most of the companies’ investment portfolios.

DOI： 10.1016/j.jclepro.2017.12.154

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Determinants of foreign direct investment in wind energy in developing countries
The renewable energy industry is one of the fastest growing industries attracting a great amount of foreign direct investment, being one of the top 5 industries in 2015 in terms of the amount of investment allocated. However, the allocation of foreign direct investment in the sector greatly varies between developing countries. Preceding studies have tried to explain the location determinants of foreign direct investment mainly by looking at the effects of institutional and macroeconomic factors. The renewable energy sector has been supported by various economic, regulatory, and political support policies. Considering the importance of these support policies, the paper analyses their effects on foreign direct investment as location determinants in comparison with that of the widely accepted determinants (institutional and macroeconomic determinants), focusing on wind energy in developing countries. The results show that renewable energy support policies have equivalent or greater effect compared to the widely accepted determinants such as corruption level, price stability, access to finance, and GDP growth. The paper demonstrates the importance of analysing determinants of foreign direct investment focusing on a specific sector rather than looking at overall foreign direct investment. The paper also provides important policy implications including the need to improve the regulatory aspect of renewable energy sector such as access to grid infrastructure in order to attract foreign direct investment into the sector.

DOI： 10.1016/j.jclepro.2017.05.106

記述言語：英語   掲載種別：研究論文（大学，研究機関等紀要）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

Renewable Energy in Pacific Small Island Developing States the role of international aid and the enabling environment from donor's perspectives
Dependency on fossil fuels is an issue for numerous countries, and in particular, it is an acutely challenging problem for Pacific Small Island Developing States. For the utilization of Renewable Energy in Pacific Small Island Developing States, donor agencies and international organizations play major roles in funding. This study introduces the nature of the past renewable energy projects in Pacific Small Island Developing States and, in the process, clarifies the contribution of international aid to renewable energy deployment. Thereafter, the paper identifies the most important factors related to enhancing an enabling environment for the introduction of Renewable Energy in Pacific Small Island Developing States and the relative importance of these factors with a special focus on donors’ perspectives. The paper clarifies that approximately 1.5 billion USD (2011) was received by Pacific Small Island Developing States over the 44 years from 1970 to 2014 as funding for renewable energy projects that included funding for hardware, and the amount of aid allocated for renewable energy in the region greatly varies between countries. The paper also identifies the important factors that can enhance an enabling environment for the introduction of renewable energy and the relative importance of these factors. Some of the highlighted implications that can be made from the findings of the research are: (1) high renewable energy targets need to be supported by well-structured action plans; (2) there is a need for an effective regulatory body responsible for renewable energy; and (3) the financial aspects of utilities are of higher importance than technological aspects of utilities.

DOI： 10.1016/j.jclepro.2016.05.011

記述言語：英語   掲載種別：研究論文（大学，研究機関等紀要）  

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1088/1755-1315/505/1/012044

出版者・発行元：Journal of Environmental Management  

As global concern over the negative impacts of global warming, primarily caused by using passenger vehicles (PVs), the transition to hydrogen fuel cell vehicles (HFCVs) is an essential alternative for reducing greenhouse (GHG) emissions. This research employs a bottom-up approach to analyze road vehicle fleet's GHG emissions. We calculated GHG emissions from PVs in 15 Group of Twenty (G20) countries based on four scenarios adopting the global HFCVs from 2024 to 2050. This paper introduces business-as-usual (BaU), moderate, aggressive, and non-HFCVs scenario. The results show that the aggressive scenario has the highest sales, estimated between 62,000 and 29.48 million vehicles by 2050, with global hydrogen market penetration rates 48.48%. Building on countries' respective national strategies, the findings highlight China and India as the leading markets for hydrogen demand, with Germany and Japan also showing significant interest. The aggressive scenario further demonstrates that transitioning from internal combustion engine vehicles (ICEVs) to battery electric vehicles (BEVs), plug-in hybrid electric vehicles (PHEVs), and HFCVs can significantly reduce annual GHG emissions. Ultimately, this study finds that the transition to HFCVs could reduce emissions by up to 67.09% by 2050.

DOI： 10.1016/j.jenvman.2024.122660

Scopus

出版者・発行元：Applied Energy  

Deploying negative emission technologies has become crucial for limiting the global temperature rise to approximately 1.5 °C above preindustrial levels. DAC technologies are being explored as one of the prospective options. These technologies have been thoroughly investigated as a potential project to capture CO2 emissions and provide purified air, natural gas, or fuel oil. An applied approach, on the other hand, was not taken into consideration while evaluating the influence that this technology has on emissions. For this reason, British Columbia provides a substantial chance to examine emissions that were produced after the DAC actions were put into place in 2015. In this study, the difference-in-differences methodology is employed for the very first time to compare the emissions that are produced by the transport sectors in British Columbia with those emitted by other provinces in Canada. The role that GDP and population play in the release of emissions is also taken into consideration in this paper. Based on the research results, it can be observed that the implementation of DAC initiatives has yielded notable effects. Evidence shows that the DAC effort has led to an average reduction of 0.08 in logarithmic CO2 emissions in the transport sector. By accounting for GDP and population, the empirical results indicate that DAC technology reduced CO2 emissions in British Columbia compared to provinces without DAC facilities. DAC initiatives are expected to become increasingly prevalent between the mid-2030s and 2040s. Overall policy implications suggest that there is a need for DAC technologies to collaborate with alternative mitigation technologies, or alternative technologies should collaborate with DAC technologies that are more efficient to achieve the targeted goals in a short time.

DOI： 10.1016/j.apenergy.2024.123112

Scopus

掲載種別：研究論文（学術雑誌）   出版者・発行元：Corporate Social Responsibility and Environmental Management  

Japan has been at the forefront of global efforts to accelerate climate change mitigation. Japanese firms have led in the development of decarbonization technologies and have positively disclosed climate change-related information based on the Task Force on Climate-related Financial Disclosures recommendations to address climate change. We explore the relationship between corporate climate change mitigation actions and the cost of capital for 2100 Japanese listed companies from 2017 to 2021. The results reveal that a higher carbon intensity correlates with an increased cost of equity, debt, and weighted average cost of capital. Interestingly, although climate-related information disclosure is associated with an increased cost of debt, it concurrently lowers the cost of equity and overall capital. This research recommends strategic approaches for firms to reduce their costs of capital while proactively combating climate change, highlighting the divergent responses of equity and bond markets to decarbonization initiatives.

DOI： 10.1002/csr.2853

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出版者・発行元：International Journal of Hydrogen Energy  

This paper precisely estimates the looming demand for hydrogen within the transportation sector, spanning 14 pivotal G20 nations from 2022 to 2050, anchored in the global vehicle hydrogen market penetration rate. Employing a robust techno-economic modeling methodology and leveraging Geographic Information System (GIS) for enriched visualization, it unveils distinct environmental dividends across three thoughtfully devised scenarios: Business-as-Usual, Moderate, and Aggressive. Findings herald India and China as pinnacles of hydrogen demand, with South Korea and Japan tailing closely. The study forecasts the energy consumption for solar hydrogen production in G20 countries to oscillate between 3.02 and 2.89 million GWh in 2022, while production costs are anticipated to range from $8.47/kg to $10.01/kg. In an assertive scenario, the paper illuminates a pathway towards achieving a significant CO2 reduction, unmasking environmental savings of up to a staggering 48%, equivalent to 1.5 million mtCO2, by 2050.

DOI： 10.1016/j.ijhydene.2023.12.246

Scopus

記述言語：その他   掲載種別：研究論文（学術雑誌）   出版者・発行元：Renewable and Sustainable Energy Reviews  

A drop in the average electricity market price owing to renewable energy with low marginal costs has been identified and explored as merit order effect. However, diffusion of variable renewable energy leads to concerns about the need for flexibility, decline of supply capacity, and volatility increase of electricity prices. For both decarbonization and stable electricity systems, understanding the drivers of market price is critical, but it is challenging because electricity markets are non-linear and affected by multiple factors. Hence, this research proposes a model based on machine learning techniques and explainable artificial intelligence (XAI) and estimates the multi-directional impact of renewable energy on the Japanese electricity market. The results reveal that the contribution of demand to market price is the largest, followed by solar generation and operable power facility capacity. This research identifies a large decline in the price triggered by solar power during the daytime; however, the effect of solar power varies by the time of day, season, and demand. Additionally, the results suggest that the market price increases when demand is high and solar generation is low, such as during summer evenings. Using XAI, this study quantitatively and visually demonstrated that interactions between solar power, demand, and operable power facility capacity are the key factors behind the high market volatility and price surge. It is important to manage the pace of plant installation and energy transition. Our study provides insights into how and when the market price changes with variable renewable energy and other policy-making factors.

DOI： 10.1016/j.rser.2023.114037

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リポジトリ公開URL： https://hdl.handle.net/2324/7182009

記述言語：その他   掲載種別：研究論文（学術雑誌）   出版者・発行元：Applied Sciences (Switzerland)  

This study investigates the impact of environmental concerns, concerns about potential accidents, and the perceived advantages of fully autonomous vehicles on individuals’ willingness to buy and the perceived value of these vehicles. Our research, conducted through a comprehensive survey with over 180,000 respondents in Japan and analyzed using structural equation modeling, reveals a nuanced disparity between willingness to buy and perceived value. We find that individuals concerned with the conservation of the natural environment are more likely to purchase fully autonomous vehicles due to their broader interest in societal issues and belief in the potential of new technologies like fully autonomous vehicles as solutions. However, these individuals attribute a lower perceived value to these vehicles, mainly because their adoption does not directly contribute to the conservation of the natural environment. Additionally, our results show that those recognizing the potential advantages of fully autonomous vehicle technology have a higher willingness to buy and perceived value, while those with apprehensions about the technology are less likely to purchase and attribute a lower perceived value to these vehicles. This study offers vital insights for policy and planning, highlighting the complex interplay of factors influencing the willingness to buy and perceived value of fully autonomous vehicles, critical for strategizing their adoption.

DOI： 10.3390/app14010410

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記述言語：その他   掲載種別：研究論文（学術雑誌）   出版者・発行元：Frontiers in Sustainability  

Sustainability study provides a roadmap to a better future. The global community is seeking a way to protect the people and the environment while supporting our economic prosperity, embodied by the UN Sustainable Development Goals (SDGs). Regrettably, however, progress toward the sustainable future has lagged through the pandemic; worse, there are some early signs that governments are reducing financing toward reaching the SDGs in the post-COVID era. Today, researchers have access to an unprecedented amount of data in the field of sustainability, and data science may hold the key to changing this tide. We can urge immediate actions for the global community by objectively analyzing the environmental, social, and economic progress toward SDGs—to open a new way to a sustainable future. It is time for us, researchers and practitioners, to reinvigorate global strides toward a sustainable future through coordinated efforts to utilize data in analyzing every aspect of sustainability. What is particularly needed today is the quantitative analysis of global development based on the empirical development of sustainability theory and observation. With this approach—which we named sustainametrics—academics may be able to present a viable path to a sustainable future.

DOI： 10.3389/frsus.2023.1130622

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リポジトリ公開URL： https://hdl.handle.net/2324/7182008

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Journal of Fusion Energy  

DOI： 10.1007/s10894-023-00361-z

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リポジトリ公開URL： https://hdl.handle.net/2324/7182007

記述言語：英語   出版者・発行元：Springer  

article number 16

CiNii Research

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Corporate Social Responsibility and Environmental Management  

Although the consideration of financial materiality is important for securing shareholders' interests, the degree of financial materiality that is considered for existing sustainability ratings is still questionable. In this study, we hand-mapped the financial materiality of environmental information based on Sustainability Accounting Standards Board (SASB) industry-specific accounting metrics to reassess environmental performance. Based on the SASB-based environmental score, we tested whether investors price environmental risk. The results show significant pricing anomalies related to environmental risk. Companies with lower SASB-based environmental scores experience higher environmental risk. Additionally, a premium in the cross-section of stock returns compensates for this risk. Our findings suggest that integrating financial materiality based on the SASB could be an effective way to capture corporate environmental risk.

DOI： 10.1002/csr.2524

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リポジトリ公開URL： https://hdl.handle.net/2324/7182006

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Elsevier  

For Japan to achieve its targets for carbon neutrality and reduction of carbon dioxide (CO2) emissions, decarbonization of road transport is essential. Japan regards next-generation vehicles, including hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), battery electric vehicles (BEVs), and fuel cell vehicles, as a key means of reducing carbon emissions from road transport. Four scenarios were proposed to predict the potential carbon emissions reduction of passenger car use in 2030: baseline, business-as-usual, government's target-based, and aggressive scenarios. Economic input–output life cycle assessment was used to evaluate potential CO2 emissions, acidification, eutrophication, human toxicity, and photochemical oxidation associated with passenger cars. In this study, all environmental impacts were calculated using the multi-regional environmentally extended supply and use/input–output database by applying the CML 2001 impact assessment method. The findings indicate that PHEVs have the lowest CO2 emissions per km traveled, followed by HEVs and BEVs. The prediction for carbon emissions from passenger cars shows that adopting electrified vehicles, such as HEVs, PHEVs, and BEVs could help decarbonize the passenger car sector. The population of vehicles, vehicle manufacturing, well-to-wheel cycle of fuel, and fuel economy will significantly contribute to CO2 emissions. Finally, this study recommends policies to steer Japan into achieving its goal of carbon neutrality.

DOI： 10.1016/j.iatssr.2023.02.004

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リポジトリ公開URL： https://hdl.handle.net/2324/7182005

記述言語：英語   出版者・発行元：MDPI  

Recently, concerns about ecosystem loss and the threat of disasters have emerged. Understanding people’s perception of the ecosystem’s value will lead to disaster adaptation through ecosystem conservation. We incorporated use and disaster attributes into a contingent valuation study to investigate Japanese peoples’ perceptions of the value of various ecosystems. We construct a concept representing ecosystems’ perceived disaster prevention and mitigation functions by investigating the effects of use status and disaster concerns on people’s preferences. Results revealed that almost all of the ecosystem’s disaster prevention and mitigation functions are not perceived by people. In some cases, people mistakenly avoid ecosystems that protect people from disasters. In conclusion, this concept and its findings facilitate an understanding of people’s perceptions of disaster prevention mitigation functions of ecosystems and promote the concrete practice of conserving ecosystems.

CiNii Research

出版者・発行元：Frontiers Media SA  

CiNii Research

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Sustainability (Switzerland)  

Recently, concerns about ecosystem loss and the threat of disasters have emerged. Understanding people's perception of the ecosystem's value will lead to disaster adaptation through ecosystem conservation. We incorporated use and disaster attributes into a contingent valuation study to investigate Japanese peoples' perceptions of the value of various ecosystems. We construct a concept representing ecosystems' perceived disaster prevention and mitigation functions by investigating the effects of use status and disaster concerns on people's preferences. Results revealed that almost all of the ecosystem's disaster prevention and mitigation functions are not perceived by people. In some cases, people mistakenly avoid ecosystems that protect people from disasters. In conclusion, this concept and its findings facilitate an understanding of people's perceptions of disaster prevention mitigation functions of ecosystems and promote the concrete practice of conserving ecosystems.

DOI： 10.3390/su15043154

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リポジトリ公開URL： https://hdl.handle.net/2324/7182003

記述言語：その他   掲載種別：研究論文（学術雑誌）   出版者・発行元：Frontiers in Sustainability  

The coronavirus (COVID-19) pandemic has affected society in immeasurable ways, including investment. As the pandemic has impacted society's values, it has proven to be a major turning point for environmental, social, and governance (ESG) investment. This investment approach, which evaluates a company's ESG ratings alongside traditional financial metrics, was already “coming off a banner year,” and its reach continues to expand. Although numerous studies have investigated the impact of ESG scores on financial returns and the trend in ESG investment strategies, only a limited number of studies have attempted to capture the key players in ESG investment. Therefore, to determine the most influential investors in the ESG investment field, the cumulative impacts are calculated based on the ESG scores of invested companies, the total market price of invested companies, and the investor history portfolio report. We perform an iteration of calculation to convey the impacts that the invested companies have on the ultimate investors, and we identify the major players in the field and differences in the trend by type of investor and country.

DOI： 10.3389/frsus.2022.909239

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リポジトリ公開URL： https://hdl.handle.net/2324/7161197

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Sustainability Science  

Weather conditions critically affect electricity demand. Recently, weather changes have also affected the electricity supply because renewable energy sources have been diffused. Some studies have revealed that weather conditions affect electricity supply or demand. However, few studies have revealed the integrated effects of weather changes on the electricity supply, demand, and market prices. This study aims to reveal the regional weather impact on the German electricity spot market based on combined hourly weather and electricity market data using structural equation modeling. Our results reveal that weather changes affect both demand and supply. First, the effect of weather on electricity supply differs in each state. Our estimation results show a more complex effect of an increase in solar radiation. Second, the electricity demand is also affected by weather conditions, particularly by temperature. Additionally, regional differences in weather conditions create a complex structure of electricity supply and demand. Our results indicate that extreme weather events in specific areas have a significant impact on the electricity market price.

DOI： 10.1007/s11625-022-01219-7

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CiNii Research

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記述言語：英語   出版者・発行元：Frontiers Media SA  

The coronavirus (COVID-19) pandemic has affected society in immeasurable ways, including investment. As the pandemic has impacted society’s values, it has proven to be a major turning point for environmental, social, and governance (ESG) investment. This investment approach, which evaluates a company’s ESG ratings alongside traditional financial metrics, was already “coming off a banner year,” and its reach continues to expand. Although numerous studies have investigated the impact of ESG scores on financial returns and the trend in ESG investment strategies, only a limited number of studies have attempted to capture the key players in ESG investment. Therefore, to determine the most influential investors in the ESG investment field, the cumulative impacts are calculated based on the ESG scores of invested companies, the total market price of invested companies, and the investor history portfolio report. We perform an iteration of calculation to convey the impacts that the invested companies have on the ultimate investors, and we identify the major players in the field and differences in the trend by type of investor and country.

CiNii Research

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Resources, Conservation and Recycling  

Reaching carbon neutrality would require the retirement of conventional power sources and substitution with renewable energy sources. Given that immediate substitution from conventional to renewable power sources is not feasible in the status quo, we investigate whether adding residential solar photovoltaic (PV) technology in addition to conventional power sources would reduce residential emissions. We use a large survey dataset of more than 300,000 observations and employ a structural equation model (SEM) to validate our findings. Interestingly, emissions increase by 1.75&#37; if residential PV is adopted, and Japanese citizens with residential PV systems end up using 3.02&#37; more electricity. We also find that pro-environmental consumers may also produce more emissions with PVs. As a result, reaching target carbon reductions in the residential sector would necessitate eliminating conventional energy sources. We address the policy implications for pathways to reduce residential emissions.

DOI： 10.1016/j.resconrec.2021.105924

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リポジトリ公開URL： https://hdl.handle.net/2324/7182002

記述言語：英語  

記述言語：その他   掲載種別：研究論文（その他学術会議資料等）  

The main goal of this paper is to contribute to a rapidly growing literature on the motivations, enabling factors and barriers to the energy transition in developing countries. We develop and compare the case studies of two developing countries - Indonesia and Vietnam - based on primary data obtained from questionnaires and in-depth interviews with key stakeholders during field surveys in 2015-2018. The main reason for the selection of these countries is the relative similarity of their energy transition paths. Although both Indonesia and Vietnam have made efforts to increase the share of renewable energy in their energy mix, the results so far have not been very encouraging. In particular, the share of energy from intermittent renewable sources such as wind and solar is still rather small. Our findings confirm the existing literature's insights about the motivations, the enabling factors and the barriers to the shift to renewables but offer much deeper understanding of some specific enabling factors and barriers. In particular, we elucidate in more depth the concerns of both developing country policymakers and private investors.

DOI： 10.1088/1755-1315/505/1/012044

記述言語：日本語   掲載種別：研究論文（学術雑誌）  

本研究は，日本における小水力発電の普及に係る障壁と課題について，事業主体の視点から明らかとすることを目的とする。筆者らが小水力発電事業実施地域に入り込み行ってきた参与観察及び小水力発電事業者への聞き取り調査とアンケート，そして先行研究を基に，小水力発電の普及に係る障壁と課題を事業主体の視点から８つ特定し，大きく次の３つのカテゴリーに整理を行った：政治的要因カテゴリー，技術・インフラ的要因カテゴリー，事業主体形成・計画・資金調達要因カテゴリー。 小水力発電事業者へのアンケートを基に，特定された各要因の重要度を，階層化意思決定法を用いて分析し，各要因の重み付けを行った。再生可能エネルギー全般において障壁となっている系統連系の問題に加えて，小水力発電には多くの許認可手続きの課題，地域住民との関わり方を含めた事業主体の形成の重要性，長期を要する開発期間の短縮のための事業計画の重要性等が確認された。これらの課題を踏まえた事業主体の形成，資金調達，そして地域住民や各種ステークホルダーとの調整を行っていくことがこれからの小水力発電の普及において重要であると考察される。本研究は，事業主体の視点に焦点をあてることによって，小水力発電の普及に係る障壁と課題を詳細に明らかにしている。

DOI： 10.3775/jie.97.245

開催年月日： 2021年5月

記述言語：英語   会議種別：口頭発表（一般）  

開催地：日本   国名：日本国  

開催年月日： 2021年1月

記述言語：英語   会議種別：口頭発表（一般）  

開催地：日本   国名：日本国  

開催年月日： 2020年9月 - 2021年9月

記述言語：英語   会議種別：口頭発表（一般）  

開催地：ドイツ   国名：ドイツ連邦共和国  

開催年月日： 2020年5月

記述言語：英語   会議種別：口頭発表（一般）  

開催地：日本   国名：日本国  

開催年月日： 2020年3月

記述言語：英語  

開催地：日本   国名：日本国  

開催年月日： 2024年3月

記述言語：日本語   会議種別：口頭発表（一般）  

開催地：九州大学   国名：日本国  

記述言語：日本語   出版者・発行元：毎日新聞出版  

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記述言語：日本語   出版者・発行元：一般社団法人 日本原子力学会  

近年注目される民間核融合業界であるが，一体誰が核融合実現を目指しているのだろうか？ベールに包まれる民間核融合業界を最新の統計データを用いて紹介する。世界には自社で核融合炉実現を目指す企業が25社存在し，資金調達額は5,000億円を超える。そのうち17社(68％)が過去10年間に設立され，また約3,000億円が2021年単年で投資されている事実は，核融合におけるスタートアップの勢いが増していることを指し示している。また核融合企業は発電(24社)から宇宙推進(11社)，水素製造(7社)まで多様な市場をターゲットとし，その半数以上(17社)が核融合発電は2030年代に実用化されると考えている。これらの統計は，民間核融合企業が短期的かつ意欲的なマイルストーンを設定して技術開発と実証を繰り返すことで，環境意識の高い投資家への訴求に成功していることを示唆する。

DOI： 10.3327/jaesjb.64.10_553

CiNii Research

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記述言語：その他   出版者・発行元：Frontiers in Sustainability  

Hydrogen is a low or zero-carbon energy source that is considered the most promising and potential energy carrier of the future. In this study, the energy sources, feedstocks, and various methods of hydrogen production from power generation are comparatively investigated in detail. In addition, this study presents an economic assessment to evaluate cost-effectiveness based on different economic indicators, including sensitivity analysis and uncertainty analysis. Proton exchange membrane fuel cell (PEMFCs) technology has the most potential to be developed compared to several other technologies. PEMFCs have been widely used in various fields and have advantages (i.e., start-up, zero-emissions, high power density). Among the various sources of uncertainty in the sensitivity analysis, the cost estimation method shows inflationary deviations from the proposed cost of capital. This is due to the selection process and untested technology. In addition, the cost of electricity and raw materials, as the main factors that are unpredictable.

DOI： 10.3389/frsus.2022.943145

Scopus

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記述言語：その他   出版者・発行元：Frontiers in Sustainability  

During the past two decades, the world has seen exponential growth in the number of companies reporting environmental, social, and governance (ESG) data, and various ESG metrics have been proposed and are now in use. ESG metrics play a crucial role as an enabler of investment strategies that consider ESG factors, which are often referred to as “ESG investments”. The ESG metrics and investment market are evolving rapidly, as investors, corporations, and the public are giving more priority to the “S” in ESG, including social equity issues, such as diversity, income inequality, worker safety, systemic racism, and companies' broader role in society. In this critical, systematic review, utilizing in-depth assessments, we investigate and compare the approaches employed in major ESG metrics and studies, then, we shed light on the “S” aspect by reviewing existing approaches used to assess social equity to clarify commensurability with ESG. Through the systematic review, this paper confirms that ESG investments can be expected to provide stable and high returns especially over the long term. This paper also clarifies how elements considered in social equity studies are largely reflected in major ESG metrics.

DOI： 10.3389/frsus.2022.920955

Scopus

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記述言語：その他   出版者・発行元：Frontiers in Sustainability  

Interest in reducing the greenhouse gas emissions from conventional power generation has increased the focus on the potential use of hydrogen to produce electricity. Numerous life-cycle assessment (LCA) studies of hydrogen-based power generation have been published. This study reviews the technological and methodological choices made in hydrogen-based power generation LCAs. A systematic review was chosen as the research method to achieve a comprehensive and minimally biased overview of hydrogen-based power generation LCAs. Relevant articles published between 2004 and 2021 were identified by searching the Scopus and Web of Science databases. Electrolysis from renewable energy resources was the most widely considered type of hydrogen production in the LCAs analyzed. Fuel cell technology was the most common conversion equipment used in hydrogen-based electricity LCAs. A significant number of scenarios examine the use of hydrogen for energy storage and co-generation purposes. Based on qualitative analysis, the methodological choices of LCAs vary between studies in terms of the functional units, allocations, system boundaries, and life-cycle impact assessment methods chosen. These discrepancies were likely to influence the value of the environmental impact results. The findings of the reviewed LCAs could provide an environmental profile of hydrogen-based electricity systems, identify hotspots, drive future research, define performance goals, and establish a baseline for their large-scale deployment.

DOI： 10.3389/frsus.2022.920876

Scopus

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記述言語：その他   出版者・発行元：Progress in Energy  

This study conducted a systematic literature review of the technical aspects and methodological choices in life cycle assessment (LCA) studies of the use of hydrogen for road transport. More than 70 scientific papers published during 2000-2021 were reviewed, in which more than 350 case studies of the use of hydrogen in the automotive sector were found. Only some studies used hybrid LCA and energetic input-output LCA, whereas most studies addressed attributional process-based LCA. A categorization based on the life cycle scope distinguished case studies that addressed the well-to-tank (WTT), well-to-wheel (WTW), and complete life cycle approaches. Furthermore, based on the hydrogen production process, these case studies were classified into four categories: Thermochemical, electrochemical, thermal-electrochemical, and biochemical. Moreover, based on the hydrogen production site, the case studies were classified as centralized, on-site, and on-board. The fuel cell vehicle passenger car was the most commonly used vehicle. The functional unit for the WTT studies was mostly mass or energy, and vehicle distance for the WTW and complete life cycle studies. Global warming potential (GWP) and energy consumption were the most influential categories. Apart from the Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation model and the Intergovernmental Panel on Climate Change for assessment of the GWP, the Centrum voor Milieukunde Leiden method was most widely used in other impact categories. Most of the articles under review were comparative LCA studies on different hydrogen pathways and powertrains. The findings provide baseline data not only for large-scale applications, but also for improving the efficiency of hydrogen use in road transport.

DOI： 10.1088/2516-1083/ac34e9

Scopus

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記述言語：日本語  

記述言語：日本語  

Determinants of Foreign Direct Investment in Renewable Energy and peculiarity of the industrial policy in China
Foreign Direct Investment is considered not just as important source of capital but valuable channel for technology transfer. The amount of Foreign Direct Investment in renewable energy has been rapidly growing in recent years, but there are great differences in the amount allocated between countries. This paper first analyzes determinants of Foreign Direct Investment in wind energy in developing countries by employing Structural Equation Modeling, and clarifies the importance of renewable energy support policies for attracting investments. And the paper further investigates into the renewable energy policies in China, which has a unique composition of Foreign Direct Investment and domestic investment in its wind energy sector. By doing so, the paper sheds light on the effect of renewable energy policies on Foreign Direct Investment, and how China became one of the leading countries in wind energy sector with their peculiar renewable energy industrial policy.

DOI： 10.20790/easoc.2018.9_21