Eric Williams

Forecasting Global Generation of Obsolete Personal Computers

Electronic waste (e-waste) has emerged as a new policy priority around the world. Motivations to address e-waste include rapidly growing waste streams, concern over the environmental fate of heavy metals and other substances in e-waste, and impacts of informal recycling in developing countries. Policy responses to global e-waste focus on banning international trade in end-of-life electronics, the premise being that e-waste is mainly generated in the developed world and then exported to the developing world. Sales of electronics have, however, been growing rapidly in developing nations, raising the question of whether informal recycling in developing countries driven by international trade or domestic generation. This paper addresses this question by forecasting the global generation of obsolete personal computers (PCs) using the logistic model and material flow analysis. Results show that the volume of obsolete PCs generated in developing regions will exceed that of developed regions by 2016-2018. By 2030, the obsolete PCs from developing regions will reach 400-700 million units, far more than from developed regions at 200-300 million units. Future policies to mitigate the impacts of informal recycling should address the domestic situation in developing countries.

Environmental effects of information and communications technologies

The digital revolution affects the environment on several levels. Most directly, information and communications technology (ICT) has environmental impacts through the manufacturing, operation and disposal of devices and network equipment, but it also provides ways to mitigate energy use, for example through smart buildings and teleworking. At a broader system level, ICTs influence economic growth and bring about technological and societal change. Managing the direct impacts of ICTs is more complex than just producing efficient devices, owing to the energetically expensive manufacturing process, and the increasing proliferation of devices needs to be taken into account.

Dynamic Hybrid Life Cycle Assessment of Energy and Carbon of Multicrystalline Silicon Photovoltaic Systems

This paper advances the life cycle assessment (LCA) of photovoltaic systems by expanding the boundary of the included processes using hybrid LCA and accounting for the technology-driven dynamics of embodied energy and carbon emissions. Hybrid LCA is an extended method that combines bottom-up process-sum and top-down economic input-output (EIO) methods. In 2007, the embodied energy was 4354 MJ/m(2) and the energy payback time (EPBT) was 2.2 years for a multicrystalline silicon PV system under 1700 kWh/m(2)/yr of solar radiation. These results are higher than those of process-sum LCA by approximately 60%, indicating that processes excluded in process-sum LCA, such as transportation, are significant. Even though PV is a low-carbon technology, the difference between hybrid and process-sum results for 10% penetration of PV in the U.S. electrical grid is 0.13% of total current grid emissions. Extending LCA from the process-sum to hybrid analysis makes a significant difference. Dynamics are characterized through a retrospective analysis and future outlook for PV manufacturing from 2001 to 2011. During this decade, the embodied carbon fell substantially, from 60 g CO(2)/kWh in 2001 to 21 g/kWh in 2011, indicating that technological progress is realizing reductions in embodied environmental impacts as well as lower module price.

Impact of Fuel Quality Regulation and Speed Reductions on Shipping Emissions: Implications for Climate and Air Quality

Atmospheric emissions of gas and particulate matter from a large ocean-going container vessel were sampled as it slowed and switched from high-sulfur to low-sulfur fuel as it transited into regulated coastal waters of California. Reduction in emission factors (EFs) of sulfur dioxide (SO₂), particulate matter, particulate sulfate and cloud condensation nuclei were substantial (≥ 90%). EFs for particulate organic matter decreased by 70%. Black carbon (BC) EFs were reduced by 41%. When the measured emission reductions, brought about by compliance with the California fuel quality regulation and participation in the vessel speed reduction (VSR) program, are placed in a broader context, warming from reductions in the indirect effect of SO₄ would dominate any radiative changes due to the emissions changes. Within regulated waters absolute emission reductions exceed 88% for almost all measured gas and particle phase species. The analysis presented provides direct estimations of the emissions reductions that can be realized by California fuel quality regulation and VSR program, in addition to providing new information relevant to potential health and climate impact of reduced fuel sulfur content, fuel quality and vessel speed reductions.

Institutional Disposition and Management of End-of-Life Electronics

Institutions both public and private face a challenge to develop policies to manage purchase, use, and disposal of electronics. Environmental considerations play an increasing role in addition to traditional factors of cost, performance and security. Characterizing current disposition practices for end-of-life electronics is a key step in developing policies that prevent negative environmental and health impacts while maximizing potential for positive social and economic benefits though reuse. To provide a baseline, we develop the first characterization of quantity, value, disposition, and flows of end-of-life electronics at a major U.S. educational institution. Results of the empirical study indicate that most end-of-first-life electronics were resold through public auction to individuals and small companies who refurbish working equipment for resale or sell unusable products for reclamation of scrap metal. Desktop and laptop computers sold for refurbishing and resale averaged U.S.

Functional Unit, Technological Dynamics, and Scaling Properties for the Life Cycle Energy of Residences

20-100 per unit, with computers sold directly to individuals for reuse reaching

Waste electrical and electronic equipment recycling in China: Practices and strategies

250-350 per unit. This detailed assessment was coupled with a benchmarking survey of end-of-life electronics management practices at other U.S. universities. Survey results indicate that while auctions are still commonplace, an increasing number of institutions are responding to environmental concerns by creating partnerships with local recycling and resale entities and mandating domestic recycling. We use the analyses of current disposition practices as input to discuss institutional strategies for managing electronics. One key issue is the tension between benefits of used equipment sales, in terms of income for the institution and increased reuse for society, and the environmental risks because of unknown downstream practices.

Modeling Cascading Diffusion of New Energy Technologies: Case Study of Residential Solid Oxide Fuel Cells in the U.S. and Internationally

Prior LCA studies take the operational phase to include all energy use within a residence, implying a functional unit of all household activities, but then exclude related supply chains such as production of food, appliances, and household chemicals. We argue that bounding the functional unit to provision of a climate controlled space better focuses the LCA on the building, rather than activities that occur within a building. The second issue explored in this article is how technological change in the operational phase affects life cycle energy. Heating and cooling equipment is replaced at least several times over the lifetime of a residence; improved efficiency of newer equipment affects life cycle energy use. The third objective is to construct parametric models to describe LCA results for a family of related products. We explore these three issues through a case study of energy use of residences: one-story and two-story detached homes, 1,500-3,500 square feet in area, located in Phoenix, Arizona, built in 2002 and retired in 2051. With a restricted functional unit and accounting for technological progress, approximately 30% of a buildings life cycle energy can be attributed to materials and construction, compared to 0.4-11% in previous studies.

Life cycle environmental implications of residential swimming pools.

CHINA plays an important role in waste electrical and electronic equipment(WEEE, also known as e-waste) recycling around the world. Over 0.7 million people were employed for e-waste recycling industry in 2007, and 98% in the informal recycling sector. These informal e-waste recycling activities pose significant threats to the environment as well public health. Based on analysis of the current policies and regulations as well as pilot projects for e-waste recycling in China, this paper aims to find out the limitations and challenges of e-waste recycling industry, and the way to overcome them. The strategy of building up an integrated e-waste management and recycling system is discussed.

Data and methodological needs to assess uncertainty in the carbon footprint of ICT products

Subsidy programs for new energy technologies are motivated by the experience curve: increased adoption of a technology leads to learning and economies of scale that lower costs. Geographic differences in fuel prices and climate lead to large variability in the economic performance of energy technologies. The notion of cascading diffusion is that regions with favorable economic conditions serve as the basis to build scale and reduce costs so that the technology becomes attractive in new regions. We develop a model of cascading diffusion and implement via a case study of residential solid oxide fuel cells (SOFCs) for combined heating and power. We consider diffusion paths within the U.S. and internationally. We construct market willingness-to-pay curves and estimate future manufacturing costs via an experience curve. Combining market and cost results, we find that for rapid cost reductions (learning rate = 25%), a modest public subsidy can make SOFC investment profitable for 20-160 million households. If cost reductions are slow however (learning rate = 15%), residential SOFCs may not become economically competitive. Due to higher energy prices in some countries, international diffusion is more favorable than domestic, mitigating much of the uncertainty in the learning rate.