• Energy Research

Abstract Product replacement programs promote the replacement of durable goods such as automobiles, home appliances and houses with new energy-efficient products using financial incentives such as subsidies. Many countries have implemented such programs to reduce environmental loads. These programs affect the point in time at which the decision to replace a product is made (and acted on) by consumers, which, in turn, influences the overall effectiveness of the program. Thus, in order to improve the policy design of these replacement programs, it is necessary to consider the mechanism of the consumer product replacement decision. This study examines the effects of the Japanese Home Appliance Eco-Point Program on the timing of household air conditioner replacements and the resulting GHG emission reduction effects and assesses the program's cost-effectiveness using a dynamic discrete choice model and an input–output model. We found that the program increased the air conditioner replacement rate by 1.5%–1.9% and reduced GHG emissions by 28,516 tCO2eq. However, the cost per ton of CO2eq reduced was approximately 978 US dollars, which is quite high compared to the GHG emission reduction costs of other programs. We conclude that the Home Appliance Eco-Point Program as constituted in 2009–2010 was not a cost-effective means to reduce GHG emissions and that appropriate policy coordination needs to be conducted in order to improve the cost-effectiveness of such programs in the future.

Extractions tests are widely used as tools to estimate the potential release of constituents, for example from waste materials, over a range of possible waste management activities, including recycling, reuse and landfill disposal. Sequential extraction procedures offer the advantage of simulating, to a certain extent, the vari ous natural environmental conditions. In this study, the mobility and bioavailability of heavy metals in wood-based bottom ash and fly ash was evaluated by the three-stage BCR sequential extraction procedure, in which elements in the bottom ash and fly ash were fractionated between acidsoluble (CH3COOH; BCR1), reducible (NH2OH-HCl; BCR2) and oxidisable (H2O2 + CH3COONH4; BCR3) fractions. For the bottom ash, the extractable concentration of Al (88 mg/kg; d.w.) and Ba (82 mg/kg; d.w.) in the BCR1 fraction were moderate, whereas the extractable concentrations of Mn (110 mg/kg; d.w.), S (310 mg/kg; d.w.) and Zn (200 mg/kg; d.w.) were relatively high. In the fly ash, the highest extractable concentrations in the BCR1 fraction were observed for S (14,400 mg/kg; d.w.) and Ba (26 mg/kg; d.w.). Therefore, when these ashes are disposed of in a landfill or utilized, for example, in earth construction, the above-mentioned metals are likely to be released from the bottom ash and from the fly ash since the elements associated with the acid-soluble (CH3COOH) fraction are more mobile and bioavailable than the metals in easily reduced (NH2OH-HCl) and oxidisable (H2O2 + CH3-COONH4) fractions.

SummaryWe conducted a decomposition analysis of material flows in a dynamic system, focusing on factors in the generation of waste consumer durables. A methodology for the analysis of consumer durables was developed and applied to three common consumer durables: cathode ray tube TVs, refrigerators, and passenger cars. The methodology decomposed changes in the numbers of waste products into three factors: changes in lifespan distribution, past trends in replacement sales, and past trends in sales for additional purchases. The decomposed equation clearly showed that the number of waste products would not necessarily be reduced by lifespan extension alone. This is because the number of waste products generated is affected not only by current lifespan distribution but also by past trends in sales for replacement and in additional purchases. The results show that changes in past replacement sales influence the current generation of waste, even if current replacement sales are declining. To reduce the generation of waste products on a short‐term basis, lifespan must be extended until the waste‐reducing effect of lifespan extension exceeds the waste‐increasing effect of the other two factors. From a long‐term perspective, controlling current replacement and additional purchases can be used to prevent future waste product generation.

SummaryLifespan is an essential parameter for the accounting and analysis of material stocks and flows, one of the main research topics in industrial ecology. Lifespan is also important as a parameter that portrays the current and historical situation of industrial metabolism, which is an area of interest to industrial ecologists.In the present article, the available information from various reports on product lifespan was reviewed. Although we found a large number of data for many durables, the definition of lifespan in published articles varied, which limited our ability to compare reported values. We therefore first defined lifespan and then compared the international and historical data.We compiled more than 1,300 data sets from various sources and identified some differences among the types of goods and among regions. With the reviewed data noted in this article, we established a database, named LiVES (Lifespan Database for Vehicles, Equipment, and Structures), and will disclose it on the Internet to share the information.

Abstract National accounts for material stocks and flows are reported regularly by an increasing number of countries to promote a sustainable use of our natural resources. In this research we build upon the work of Herman Daly and Donella Meadows and propose a framework that links material stocks and flows to a conceptual hierarchy of ends and means which are societal benefit and natural capital. We introduce a set of six indicators that link together to quantitatively relate material consumption and societal benefits: material productivity, primary material use rate, stock retention time, stock productivity, service productivity, and service utilization. We apply this analytical framework to accounts of the material stocks and flows of Japan for the period 1990 to 2015. We find that Japan’s material flow productivity doubled from 1.6 US$/kg to 3.2 US$/kg. This improvement can be primarily attributed to improvements in stock retention rates and circular material use, but has been offset by decreasing productivity of Japan’s material stocks from 0.2 US$/kg to 0.14 US$/kg. We discuss the future potential of our indicator framework to include additional indicators for specific sectors and argue for the need for proper measurements of societal services and human wellbeing to enhance the policy implications of the indicator framework.

SummaryLifespan of commodities is essential information for material flow analysis and material stock accounting. Lifespan data is available in the literature; however, it varies in definition and in methodology employed. This article reviews and categorizes different types of lifespan distribution and distribution estimation methodologies, and investigates the relationship and differences between lifespan definitions and estimation methodologies. Lifespan distribution of commodities can be classified into five types from two perspectives: base year for which the distribution is drawn, and vertical axis of the distribution. The methodologies for estimating lifespan distribution were classified into four types and the details of each methodology and the relationship to the definition of lifespan were also clarified. This article also examines differences in actual lifespan data—between the types of distribution, the definitions, and the employed methodologies—by comparing reported data in literature. Any of the four methodologies are theoretically applicable and provide the same value of a lifespan; however unless accurate data such as census statistics are available, lifespan data can vary, and therefore we must be very cautious about the representativeness of sample data.

To clarify current collection rules of waste batteries in municipal waste management in Japan and to examine future challenges for hazardous substance control and safety, we reviewed collection rules of waste batteries in the Tokyo Metropolitan Area. We also conducted a field survey of waste batteries collected at various battery and small waste electric and electronic equipment (WEEE) collection sites in Tokyo. The different types of batteries are not collected in a uniform way in the Tokyo area, so consumers need to pay attention to the specific collection rules for each type of battery in each municipality. In areas where small WEEE recycling schemes are being operated after the enforcement of the Act on Promotion of Recycling of Small Waste Electrical and Electronic Equipment in Japan in 2013, consumers may be confused about the need for separating batteries from small WEEE (especially mobile phones). Our field survey of collected waste batteries indicated that 6-10% of zinc carbon and alkaline batteries discarded in Japan currently could be regarded as containing mercury. More than 26% of zinc carbon dry batteries currently being discarded may have a lead content above the labelling threshold of the EU Batteries Directive (2006/66/EC). In terms of safety, despite announcements by producers and municipalities about using insulation (tape) on waste batteries to prevent fires, only 2.0% of discarded cylindrical dry batteries were insulated. Our field study of small WEEE showed that batteries made up an average of 4.6% of the total collected small WEEE on a weight basis. Exchangeable batteries were used in almost all of mobile phones, digital cameras, radios, and remote controls, but the removal rate was as low as 22% for mobile phones. Given the safety issues and the rapid changes occurring with mobile phones or other types of small WEEE, discussion is needed among stakeholders to determine how to safely collect and recycle WEEE and waste batteries.