The word “Energy LCA” has a double meaning. First, the word means LCA that focuses on energy requirement as an environmental impact, for example, estimating embodied energy requirements for a wide range of goods and services throughout their life cycles. Second meaning of the word is LCA for energy supply technologies or systems, for example, to estimate environmental impacts such as CO₂ and solid waste emissions across the life cycle of solar photovoltaic power generation. The present paper gives an overview of various “Energy LCA” conducted from past to present considering the double meaning, and then presents future developments of “Energy LCA” from the perspective of its contribution to formulating energy and environmental policies.

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This paper focuses on power generation systems and reviews the analytic method of LCA from past to present. Noted results of life cycle CO₂ emissions (LCCO₂) and some problems in evaluating LCCO₂ are shown for grid power, renewable energy power and dispersed power. Net energy ratio, the ratio of the total energy production to the input energy except fuels, was an important index that shows how efficient the power generation technology is. Net energy ratio, however, was replaced with LCCO₂ with the growing interest in global warming and the spread of LCA. Authorized results are known regarding LCCO₂ of grid power and main renewable energy power. On the other hand, there remain some difficult problems regarding LCCO₂ of dispersed power utilizing hydrogen or biomass in terms of data acquisition and evaluation method.

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The objective of this commentary is to explain the outline of comprehensive environmental impact assessment maethods for energy conversion and utilization including case examples. Since energy often uses fossil fuel as its raw material, that is, energy source, evaluation is frequently made focusing on the amount of greenhouse gases emitted at the time of conversion and use and the influence on global warming. This also applies to the evaluation of new energy and renewable energy that replace fossil fuel. However, it is necessary to assess energy conversion and utilization from the perspectives of not only global warming but also overall environmental impacts.

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Renewable energy is considered to have the potential to achieve social and economic development while reducing environmental impact. However, there still exists a lack of understanding on how this win-win potential is actualized. This article introduces the discussion on renewable energy and its impact on employment. The literature is reviewed according to the following research objectives : i) to determine the employment effects of renewable energy policies, ii) to study the effects of renewable energy on rural employment, iii) to identify the differences among various types of renewable energy technologies in terms of the employment effects. Directions for future research are also discussed.

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Bioethanol is a biofuel that substitutes for gasoline and is adapted globally as one of the measures for reducing the emissions of greenhouse gases (GHGs). Meanwhile, bioethanol has various effects on reduction of GHGs emissions, differing from feedstocks to production methods. To reduce GHGs effectively, therefore, it is necessary to introduce the sort of bioethanol that has high GHGs reduction potential through the implementation of life-cycle assessment (LCA). This article presents the aspects of the Act on Sophisticated Methods of Energy Supply Structures, a measure that introduced promotion of bioethanol in Japan, as a case of LCA utilization in the energy industry.

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The utilization of hydrogen as an energy carrier is promoted in major countries as one of the major climate change countermeasures. Regarding hydrogen energy utilization, it is important that not only reducing greenhouse gas emission at the use stage, but also reducing the emissions from hydrogen production until its use be evaluated. Therefore, the Ministry of the Environment regarded a need of LCA (Life Cycle Assessment), which is a technique to assess environmental impacts through life cycle of products or services. The Ministry of the Environment established LCA guidelines for hydrogen energy manufacturers, sales companies and final users to evaluate their own hydrogen energy business in Japan. In order to reduce manhour for the calculation and reduce the error in the calculation, a LCA calculation tool was also developed. This tool equipped with two types of LCI databases, process-based database and input-output table based database. Furthermore, manual of the tool and samples using the tool were produced. The tool, manual and samples are available on the website of the Ministry of the Environment.

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The objective of this research is to develop an environmental information provision approach for supporting consumers’ life cycle thinking (LCT). We developed an environmental education program for junior high-school students, and a scenario analysis software to evaluate environmental impacts associated with consumers’ product use. The effectiveness of the two approaches was evaluated in enhancing skills required for LCT-based design of proenvironmental behavior. The comparison between disposable plastic shopping bags and reusable shopping bags was used as an example of product comparison in both approaches. The education program to systemically learn LCT was implemented in lectures for comprehensive studies. The analysis results of effectiveness show that LCT skills of the participants have increased after the program. We also developed the software to analyze environmental impacts associated with decision making in using shopping bags. It can assess the amount of CO₂ emission associated with current decisions and can propose measures for CO₂ reduction. The software was distributed through a web-based survey, and similar analyses were conducted on respondents. The results show that LCT skills and environmental awareness of the respondents provided with environmental information by the software have significantly increased. These results indicated that the developed approaches were effective in enhancing consumers’ LCT skills.

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A primary survey on the time-dependent influence of life cycle thinking-based environmental education (LCT-EE) on pro-environmental awareness and behavior was carried out for learners who took a class of LCT-EE for the detailed design of a survey on the education effects of LCT-EE. The present survey was performed by using a questionnaire form. In this form, survey respondents were asked three question items with respect to a change in pro-environmental awareness and behavior before and after the class. The reasons for their responses to the two items on pro-environmental behavior were also asked in a multiplechoice method on the basis of the other related research results. We sent a questionnaire to 96 learners and we had a response from 77 learners. The result suggested that the exposure to LCT-EE contributed to a positive change in pro-environmental awareness after the elapse of a certain period of time. We also obtained two important potentials with regard to the influence of the learning of LCT on pro-environmental awareness and behavior. We will continue this project towards the detailed survey on the education effects of LCT-EE in order to interpret the mechanism of a change in pro-environmental behavior based on the learning of LCT.

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This study evaluated the lifecycle reduction potential and the payback time of CO₂ originated from general detached household electricity consumption by introducing the DC LED lighting system utilizing photovoltaic power generation and storage battery. Among various DC LED lighting systems, the system with storage battery capacity adjusted to night lighting power demand showed relatively high CO₂ reduction potential. In the system with storage battery capacity extended to whole daytime surplus power generation, shortening of battery lifetime caused by repeated complete discharge should affect lifecycle CO₂ increase of the system. The CO₂ payback time of DC LED lighting system varied between 1.5 and 2 years according as several regional characteristics such as electrical grid CO₂ emission factor, photovoltaic power condition and storage battery lifetime related to the required capacity.

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Consumption pattern is recognized as a key factor in the pursuit of sustainable development within institutional debate. However, measures for alternative consumption pattern has long focused on the production side due to the lack of well-founded understanding in consumer behavior, and institutional reticence to be engaged in actions that question the structure of modern society. In the recent years, academic research in consumption pattern and lifestyle is gaining recognition in the field of Sustainability Science. To identify the research trends and methodologies embarked on consumption pattern in Sustainability Science, quantitative and qualitative literature review was conducted on three core journals of Sustainability Science. The results find that current research effort focuses on the sustainability of resources, and there is a dearth of attention in connecting consumption with well-being.

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