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Project: Life Cycle Assessment of IT hardware Summary: Life Cycle Assessment (LCA) refers to the quantitative
characterization of the environmental impacts of products and services over
the chain of processes include mining, manufacture, operation and disposal. A
life cycle perspective can lead to qualitatively different understanding of
environmental management. This is particularly true for IT products. For
example, a study of the supply chain use of energy, chemicals in the supply
chain yielding a 32MB DRAM memory chip showed that at least 1,200 grams of
fossil fuels and 72 grams of chemicals are needed to produce one 2-gram
memory chip. The amount of environmentally sensitive materials used far
belies its tiny size, fossil fuels for production are some 600 times the
weight of the chip. By comparison, the total fossil fuel needed to produce an
automobile is 1-2 times of its weight and 4-5 times for an aluminum can. The
production chain yielding silicon wafers from quartz uses 160 times the
energy required for typical silicon, indicating that purification to
semiconductor grade materials is energy intensive. Due to its extremely
low-entropy, organized structure, the materials intensity of a microchip is
orders of magnitude higher than that of “traditional” goods. A follow-up study of the total energy used
in producing a desktop computer with 17-inch CRT monitor estimates that 6,400
megajoules (MJ), equivalent to 260 kg of fossil fuels. This high energy
intensity of manufacturing, combined with rapid turnover in computers,
results in an annual life cycle energy burden that is surprisingly high:
about 2,600 MJ per year, 1.3 times that of a refrigerator. In contrast with
many home appliances, life cycle energy use of a computer is dominated by
production (80%) as opposed to operation (20%). Extension of usable lifespan
(e.g. by reselling or upgrading) is thus a promising approach to mitigating
energy impacts, as well as other environmental burdens associated with
manufacturing and disposal. The project work to develop life cycle
methods and results to improve the characterization and management of the
life cycle of IT hardware. Methodologically the focus is on improving
characterization of uncertainty in life cycle inventories and reducing this
uncertainty using hybrid methods. Recent papers address time trends and the
effects of increased purity demands on energy use in manufacturing. Publications: Case Studies in Energy Use to Realize
Ultra-High Purities in Semiconductor Manufacturing, N. Krishnan, E.
Williams and S. Boyd, in Proceedings of the 2008 IEEE International Symposium
on Electronics and the Environment, San Francisco, CA (2008) Measures and Trends in Energy Use of
Semiconductor Manufacturing, L. Deng and E. Williams, in Proceedings of the
2008 IEEE International Symposium on Electronics and the Environment, San
Francisco, CA (2008) Carbon Emissions Embodied in
Importation, Transport and Retail of Electronics in the U.S.: A Growing
Global Issue, C. Weber, H. Scott Matthews, J. Corbett and E. Williams, in Proceedings
of the 2007 IEEE International Symposium on Electronics and the Environment,
IEEE: Piscataway, New Jersey, 174-179 (2007) Energy intensity of computer manufacturing: hybrid analysis combining process and economic input-output methods, E. Williams, Environmental Science & Technology 38(22), 6166 - 6174 (2004) (view abstract) The environmental impacts of
semiconductor fabrication, E.
Williams, Thin Solid Films 461(1), 2-6 (2004) Forecasting Material and Economic Flows
in the Global Production Chain for Silicon, E. Williams, Technological Forecasting and Social Change 70(4),
341-357 (2003) The 1.7 Kilogram Microchip: Energy and Material Use in the Production of Semiconductor Devices. E. Williams, R. Ayres, and M. Heller. Environmental Science & Technology 36 (24). 5504-5510. Dec. 15 (2002) (view abstract) Contact: For more information and/or copies of
publications, please contact: Eric Williams |
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