Residential computer usage patterns in Japan and associated life cycle energy use

Computer purchase, operation and disposition patterns are characterized via a survey of about 1,000 Japanese residential users. The mains purposes are a) to better characterize the energy burden of the national IT infrastructure and b) to understand the status and prospects of the market for used equipment. Results include that the average length between buying new PCs in is 2.9 years, older computers typically spend 2.8 years unused in closets before next disposition (donation, recycling, or other). These and other results are used to estimate that annual life cycle energy burden of home PCs in Japan is 9.7 × 10¹⁰ megajoules (MJ), 0.64% of total energy demand. Considering prospects for the used market, apparently there is a large untapped potential supply of used computers: only about 13% of users reported having sold or purchased a used PC, and 55% said that they had never considered selling a computer. There is likely a "hole" in the supply of mid-level used PCs (2-4 years old), with high-end ones (1-2 years old) being sold by power users buying new machines, and low-end ones (5-6 year) coming from storage. Potential demand is less promising: users report many concerns about purchasing used computers, such as warranties, reliability, and desire to have "my own" computer. There is likely much higher demand for used PCs in neighboring countries in developing Asia. Prompt reselling of used computers by Japanese users could potentially open a door to supplying inexpensive, quality computers for the export market.