Metals Production Requirements for Rapid Photovoltaics Deployment

If global photovoltaics (PV) deployment grows rapidly, the required input materials need to be supplied at an increasing rate. In this paper, we quantify the effect of PV deployment levels on the scale of metals production. For example, we find that if cadmium telluride {copper indium gallium diselenide} PV accounts for more than 3% {10%} of electricity generation by 2030, the required growth rates for the production of indium and tellurium would exceed historically-observed production growth rates for a large set of metals. In contrast, even if crystalline silicon PV supplies all electricity in 2030, the required silicon production growth rate would fall within the historical range. More generally, this paper highlights possible constraints to the rate of scaling up metals production for some PV technologies, and outlines an approach to assessing projected metals growth requirements against an ensemble of past growth rates from across the metals production sector. The framework developed in this paper may be useful for evaluating the scalability of a wide range of materials and devices, to inform technology development in the laboratory, as well as public and private research investment

Historical costs of coal-fired electricity and implications for the future

We study the cost of coal-fired electricity in the United States between 1882 and 2006 by decomposing it in terms of the price of coal, transportation cost, energy density, thermal efficiency, plant construction cost, interest rate, capacity factor, and operations and maintenance cost. The dominant determinants of cost have been the price of coal and plant construction cost. The price of coal appears to fluctuate more or less randomly while the construction cost follows long-term trends, decreasing from 1902 to 1970, increasing from 1970 to 1990, and leveling off since then. Our analysis emphasizes the importance of using long time series and comparing electricity generation technologies using decomposed total costs, rather than costs of single components like capital. By taking this approach we find that the history of coal-fired electricity suggests there is a fluctuating floor to its future costs, which is determined by coal prices. Even if construction costs resumed a decreasing trend, the cost of coal-based electricity would drop for a while but eventually be determined by the price of coal, which fluctuates while showing no long-term trend.National Science Foundation (U.S.) (NSF Grant SBE0738187

The Role of Design Complexity in Technology Improvement

We study a simple model for the evolution of the cost (or more gen- erally the performance) of a technology or production process. The technology can be decomposed into n components, each of which interacts with a cluster of dWe study a simple model for the evolution of the cost (or more gen- erally the performance) of a technology or production process. The technology can be decomposed into n components, each of which interacts with a cluster of dRefereed Working Papers / of international relevanc

Methane mitigation timelines to inform energy technology evaluation

Energy technologies emitting differing proportions of methane (CH[subscript 4]) and carbon dioxide (CO[subscript 2]) vary significantly in their relative climate impacts over time, due to the distinct atmospheric lifetimes and radiative efficiencies of the two gases. Standard technology comparisons using the global warming potential (GWP) with a fixed time horizon do not account for the timing of emissions in relation to climate policy goals. Here we develop a portfolio optimization model that incorporates changes in technology impacts based on the temporal proximity of emissions to a radiative forcing (RF) stabilization target. An optimal portfolio, maximizing allowed energy consumption while meeting the RF target, is obtained by year-wise minimization of the marginal RF impact in an intended stabilization year. The optimal portfolio calls for using certain higher-CH[subscript 4]-emitting technologies prior to an optimal switching year, followed by CH[subscript 4]-light technologies as the stabilization year approaches. We apply the model to evaluate transportation technology pairs and find that accounting for dynamic emissions impacts, in place of using the static GWP, can result in CH[subscript 4] mitigation timelines and technology transitions that allow for significantly greater energy consumption while meeting a climate policy target. The results can inform the forward-looking evaluation of energy technologies by engineers, private investors, and policy makers.MIT Energy InitiativeMassachusetts Institute of Technology. Charles E. Reed Faculty Initiative FundNew England University Transportation Center (DOT Grant DTRT12-G-UTC01)National Science Foundation (U.S.). Graduate Research Fellowship (Grant 1122374

Growth in metals production for rapid photovoltaics deployment

If global photovoltaics (PV) deployment grows rapidly, the required input materials need to be supplied at an increasing rate. We quantify the effect of PV deployment levels on the scale of annual metals production. If a thin-film PV technology accounts for 25% of electricity generation in 2030, the annual production of thin-film PV metals would need to grow at rates of 15-30% per year. These rates exceed those observed historically for a wide range of metals. In contrast, for the same level of crystalline silicon PV deployment, the required silicon production growth rate falls within the historical range.United States. Dept. of Energy (Grant DE-EE0006131

Personal Vehicles Evaluated against Climate Change Mitigation Targets

Meeting global climate change mitigation goals will likely require that transportation-related greenhouse gas emissions begin to decline within the next two decades and then continue to fall. A variety of vehicle technologies and fuels are commercially available to consumers today that can reduce the emissions of the transportation sector. Yet what are the best options, and do any suffice to meet climate policy targets? Here, we examine the costs and carbon intensities of 125 light-duty vehicle models on the U.S. market today and evaluate these models against U.S. emission-reduction targets for 2030, 2040, and 2050 that are compatible with the goal of limiting mean global temperature rise to 2 °C above preindustrial levels. Our results show that consumers are not required to pay more for a low-carbon-emitting vehicle. Across the diverse set of vehicle models and powertrain technologies examined, a clean vehicle is usually a low-cost vehicle. Although the average carbon intensity of vehicles sold in 2014 exceeds the climate target for 2030 by more than 50%, we find that most hybrid and battery electric vehicles available today meet this target. By 2050, only electric vehicles supplied with almost completely carbon-free electric power are expected to meet climate-policy targets

Finding Lost Space: Theories of Urban Design

The problem of "lost space," or the inadequate use of space, afflicts most urban centers today. The automobile, the effects of the Modern Movement in architectural design, urban-renewal and zoning policies, the dominance of private over public interests, as well as changes in land use in the inner city have resulted in the loss of values and meanings that were traditionally associated with urban open space. This text offers a comprehensive and systematic examination of the crisis of the contemporary city and the means by which this crisis can be addressed. Finding Lost Space traces leading urban spatial design theories that have emerged over the past eighty years: the principles of Sitte and Howard; the impact of and reactions to the Functionalist movement; and designs developed by Team 10, Robert Venturi, the Krier brothers, and Fumihiko Maki, to name a few. In addition to discussions of historic precedents, contemporary approaches to urban spatial design are explored. Detailed case studies of Boston, Massachusetts; Washington, D.C.; Goteborg, Sweden; and the Byker area of Newcastle, England demonstrate the need for an integrated design approach--one that considers figure-ground, linkage, and place theories of urban spatial design. These theories and their individual strengths and weaknesses are defined and applied in the case studies, demonstrating how well they operate in different contexts. This text will prove invaluable for students and professionals in the fields of architecture, landscape architecture, and city planning. Finding Lost Space is going to be a primary text for the urban designers of the next generation. It is the first book in the field to absorb the lessons of the postmodern reaction, including the work of the Krier brothers and many others, and to integrate these into a coherent theory and set of design guidelines. Without polemics, Roger Trancik addresses the biggest issue in architecture and urbanism today: how can we regain in our shattered cities a public realm that is made of firmly shaped, coherently linked, humanly meaningful urban spaces? Robert Campbell, AIA Architect and architecture critic Boston Globe

Temporary Intervention and Long Term Legacy: Lessons from London Case Studies

The paper explores the issue of temporary projects on vacant land focusing on London in the 2007-2012 downturn. Using a case study approach, a link has been identified between the success of temporary projects and a longer-term vision, as well as a move toward better integration between temporary occupants and developer/land-owner. Within this paradox the whole idea of temporariness is put under question, as is the traditional mainstream depiction of bottom-up in opposition to top-down action. These trends are contextualised within the dynamics of recession that has triggered new types of creative conversations between parties traditionally considered in opposition and may contribute to reframing urban development as an incremental, organic and collaborative process