Timothy Johnson, Diffusion of Carbon Management Technologies; Science and Technology Policy; Quantitative and Qualitative Modeling for Decision Analysis
Committee: Howard Herzog (MIT), David Keith - chair (EPP), Granger Morgan (EPP/ECE/Heinz), and Edward Rubin (EPP/ MechE)
      This thesis analyzes how technologies to capture and sequester carbon dioxide in fossil-fired power plants might enter real electric utility systems given their existing mix of capital plant and dispatch order. A capacity planning and dispatch model is used to examine how the current distribution of generating units, natural gas prices, and other industry trends would affect the cost of CO2 control via carbon capture and sequestration in an actual U.S. electric market (PJM).
      The analysis finds that by the year 2025 plants with CO2 capture consistently provide significant reductions in base-load emissions at carbon prices near 100 $/tC, but do not offer an economical means of meeting peak demand unless CO2 reductions in excess of 80 percent are required. Various scenarios estimate the amount by which turnover of the existing generating infrastructure and the severity of criteria pollutant constraints reduce mitigation costs. sequestration in the seabed beneath the       A look at CO2 U.S. outer continental shelf complements this model-driven assessment by considering issues of risk, geological storage capacity, and regulation. Extensive experience with offshore oil and gas operations suggests that the technical uncertainties associated with outer continental shelf sequestration are not disposal under U.S. law and large. The legality of seabed CO2 international environmental agreements, however, is ambiguous, and the outer continental shelf may be the first region where these regulatory regimes clash over CO2 sequestration. Work supported by The Center for Integrated Study of the Human Dimensions of Global Change through a cooperative agreement between NSF (SBR-9521914) and Carnegie Mellon.

Kanchana Wanichkorn, The Role of Fixed Wireless Access Networks in the Deployment of Broadband Services and Competition in Local Telecommunications Markets
Committee: Alex Hills (EPP/SCS), Jon Peha (EPP/ECE), Marvin Sirbu - chair (EPP/ECE/IA), and Daniel Stancil (ECE)

      Through the use of an engineering-economic model, this thesis analyzes the cost structure of broadband fixed wireless access (BFWA) networks and examines their economic viability of providing voice over IP and broadband Internet access services as compared to Digital Subscriber Line (DSL) and cable modem networks. On average, costs of BFWA networks are higher than costs of DSL and cable modem networks. Until BFWA electronics become significantly cheaper, it is unlikely that BFWA will be a third option for broadband services in urban areas where both DSL and cable modem services are available. However, in rural areas, BFWA is the only viable choice to provide voice over IP and broadband Internet access services.
      If more spectrum becomes available, it can be used to lower costs of urban wireless networks but this will not reduce rural costs. However, the use of 700 MHz UHF spectrum instead of 2.6 GHz MMDS spectrum does lower costs, especially in rural areas, because of the longer range that is possible. To foster the development of BFWA in rural areas, we recommend at least 36 MHz of the upcoming 700 MHz spectrum be licensed in small geographic areas. This would offer an opportunity for providers interested in implementing BFWA networks in rural areas to outbid mobile providers focused on urban areas. Because of the cost advantage in rural areas, if and when broadband internet is included in the definition of universal service, BFWA networks should be qualified to receive universal service subsidies. Work supported in part by a grant from the Carnegie Mellon Information Networking Institute, the MIT Program on Internet & Telecoms Convergence, and the Royal Thai Government.

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