Technology cost drivers for a potential transition to decentralized manufacturing

Popular dialogue around additive manufacturing (AM) often assumes that AM will cause a move from centralized to distributed manufacturing. However, distributed configurations can face additional hurdles to achieve economies of scale. We combine a Process-Based Cost Model and an optimization model to analyze the optimal location and number of manufacturing sites, and the tradeoffs between production, transportation and inventory costs. We use as a case study the commercial aviation maintenance market and a titanium jet engine bracket as an exemplar of a class of parts that are not flight-critical. We run our analysis for three different scenarios, one corresponding to the current state of the technology, and two which represent potential improvements in AM technology. Our results suggest that the cost-minimizing number of manufacturing locations does not vary significantly when taking into account a range of plausible improvements in the technology. In this case, distributed manufacturing is only favorable for a set of non-critical components that can be produced on the same equipment with minimal certification requirements and whose annual demand is in the tens of thousands. Distributed manufacturing is attractive at lower volumes for components that require no hot isostatic pressing

Reducing Pollution from Aviation and Ocean Shipping

<p>International aviation and ocean shipping are significant and potentially fast growing sources of greenhouse gas emissions. Both sectors also contribute to poor local and regional air quality. This thesis analyzes three interventions aimed at reducing air emissions from airplanes and ships. The first is the use of tugs, or an electric motor embedded in the landing gear, to propel the aircraft on the ground. If airlines were to tow all large narrowbody aircraft on domestic service from the gate to the edge of the runway before take off at 41 of the 50 busiest airports in the U.S., CO2 emissions would fall by 0.5 million tonnes annually. In addition, the switch would produce $150 million in annual air quality benefits from reduced emissions of particulate matter, hydrocarbons and the oxides of nitrogen. Using embedded electric motors to taxi large narrowbody aircraft would cut CO2 emissions by nearly 2 million tonnes per year. The second intervention is the market based mechanism, designed to cap CO2 emissions from international aviation at 2020 levels, currently being designed at ICAO. An analysis of an early draft of this mechanism suggests that it would require airlines to offset an average of 270 million tonnes in CO2 emissions during each of the years between 2021 and 2035 when it will be active. The analysis suggests that the current proposal is complex, and poorly specified. We recommend that the mechanism be made much simpler: for example, by simply determining an airline’s offset obligations on the basis of its carbon footprint in that year. Finally, we study the costs and benefits of a more widespread use of grid electricity to energize berthed vessels. We use mixed-integer linear programming to identify combinations of ports and vessels where using shore power would produce the greatest benefit to society. We conclude that the practice could reduce CO2 emissions by 0.2 million tonnes per year and yield air quality improvements worth$80-200 million per year at no net cost to society.</p

EXECUTIVE SUMMARY

Development Group as an entry in the 201

US residential heat pumps: the private economic potential and its emissions, health, and grid impacts

To explore electrification as a climate change mitigation strategy, we study US residential heat pump adoption, given the current US housing stock. Our research asks (a) how the costs and benefits of heat pump adoption evolve with increased penetration, (b) what rate of heat pump adoption is economic given today’s housing stock, electric grid, energy prices, and heat pump technology, and (c) what effect changing policies, innovations, and technology improvements might have on heat pump adoption. We answer these research questions by simulating the energy consumption of 400 representative single-family houses in each of 55 US cities both before and after heat pump adoption. We use energy prices, CO _2 emissions, health damages from criteria air pollutants, and changes in peak electricity demand to quantify the costs and benefits of each house’s heat pump retrofit. The results show that 32% of US houses would benefit economically from installing a heat pump, and 70% of US houses could reduce emissions damages by installing a heat pump. We show that the potential for heat pump adoption varies depending on electric grid, climate, baseline heating fuel, and housing characteristics. Based on these results we identify strategic, technology, and policy insights to stimulate high heat pump adoption rates and deep electrification of the US residential heating sector, which reduces CO _2 emissions and the impacts of climate change

Decarbonization potential of electrifying 50% of U.S. light-duty vehicle sales by 2030

Abstract The U.S. federal government has established goals of electrifying 50% of new light-duty vehicle sales by 2030 and reducing economy-wide greenhouse gas emissions 50-52% by 2030, from 2005 levels. Here we evaluate the vehicle electrification goal in the context of the economy-wide emissions goal. We use a vehicle fleet model and a life cycle emissions model to project vehicle sales, stock, and emissions. To account for state-level variability in electric vehicle adoption and electric grid emissions factors, we apply the models to each state. By 2030, greenhouse gas emissions are reduced by approximately 25% (from 2005) for the light-duty vehicle fleet, primarily due to fleet turnover of conventional vehicles. By 2035, emissions reductions approach 45% if both vehicle electrification and grid decarbonization goals (100% by 2035) are met. To meet climate goals, the transition to electric vehicles must be accompanied by an accelerated decarbonization of the electric grid and other actions

A Rare Case of Gradenigo Syndrome: Sequelae to Otomastoiditis

Gradenigo syndrome is a triad comprising of abducens nerve palsy, trigeminal neuralgia and petrous apicitis. It is quite rare complication of otitis media. In this study, we report a rare case of a 17-year-old girl who presented with sudden onset of diplopia and left periorbital pain on imaging showed otomastoidits, petrous apicitis and epidural abscesses surrounding it

Policy needed for additive manufacturing

The successful adoption of metallic additive manufacturing in aviation will require investment in basic scientific understanding of the process, defining of standards and adaptive regulation

Getting past the hype about 3-D printing

The hope for additive manufacturing is that it will revolutionize manufacturing.1 Although additive manufacturing — also known as 3-D printing — was developed back in the 1980s, it has garnered increased attention in recent years as managers look for ways to improve efficiency and reduce production costs. Managers hope that much the way GE’s new printed nozzle for jet engines has reduced the need for expensive materials and energy,2 3-D-printed parts will cut lead times and make supply chains more efficient in a wide range of settings.3\u3cbr/\u3e\u3cbr/\u3eDespite the potential of additive manufacturing, we believe that near-term expectations for it are overblown. We base this conclusion on our research, which included 80 interviews as well as extensive study of the literature on the history of materials and process technologies, industry meetings, and factory visits.4 (See “About the Research.”