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Papers

Contents

  1. 1 Energy Systems
    1. 1.1 Life cycle assessment of integrated seawater agriculture in the Arabian (Persian) Gulf as a potential food and aviation biofuel resource
    2. 1.2 Characterization of the Chemical Composition of the Halophyte Salicornia bigelovii under Cultivation.
    3. 1.3 A Land Suitability Study for the Sustainable Cultivation of the Halophyte Salicornia bigelovii: The Case of Abu Dhabi, UAE.
    4. 1.4 Tags: bioenergy, halophyte, saline agriculture, simple limitation method
    5. 1.5 Aviation Industry’s Quest for a Sustainable Fuel: Considerations of Scale and Modal Opportunity Carbon Benefit.
    6. 1.6 Tags: Energy, biofuels, sustainable aviation, comparative
    7. 1.7 Solar-assisted Post-combustion Carbon Capture feasibility study
    8. 1.8 Systematic comprehensive techno-economic assessment of solar cooling technologies using location-specific climate data
  2. 2 Sustainable Energy Transitions, Economics, Policy and Design
    1. 2.1 The Sower's Way: Quantifying the Narrowing Net-Energy Pathways to a Global Energy Transition
    2. 2.2 RE-mapping the UAE’s energy transition: An economy-wide assessment of renewable energy options and their policy implications
    3. 2.3 A Framework for Defining Sustainable Energy Transitions: Principles, Dynamics, and Implications
    4. 2.4 A sustainable energy transition strategy for the United Arab Emirates: Evaluation of options using an Integrated Energy Model
    5. 2.5 Defusing the Energy Trap: The Potential of Energy-Denominated Currencies to facilitate a Sustainable Energy Transition
    6. 2.6 Tangible and fungible energy: Hybrid energy market and currency system for total energy management. A Masdar City case study.
    7. 2.7 Rigorous classification and carbon accounting principles for low and Zero Carbon Cities
  3. 3 Transportation Systems
    1. 3.1 Game Theory Analysis of the Impact of Single Aisle Aircraft Competition on Fleet Emissions
    2. 3.2 Air transportation for a carbon constrained world: Long-term Dynamics of Policies and Strategies for Mitigating the Carbon Footprint of Commercial Aviation
    3. 3.3 Simulation-based Analysis of Personal Rapid Transit System Implementation: Application in Masdar City Transportation System.
    4. 3.4 Double Hull Phase-In in the Maritime Industry: The Effects of Sunk Cost and Uncertainty
    5. 3.5 New Approach to Transportation Planning for the 21st Century: Regional Strategic Transportation Planning as a CLIOS Process
    6. 3.6 Simulation Analysis for Midterm Yard Planning in Container Terminal

Energy Systems


Life cycle assessment of integrated seawater agriculture in the Arabian (Persian) Gulf as a potential food and aviation biofuel resource


Brian Warshay, J. Jed Brown, and Sgouris Sgouridis. (2016) The International Journal of Life Cycle Assessment DOI: 10.1007/s11367-016-1215-5. (Link)

Abstract: Purpose: Prospective evaluation of the lifecycle impacts of aviation biofuel production in Abu Dhabi, UAE based on a production system that integrates aquaculture, saltwater agriculture, and mangrove silviculture, termed an Integrated Seawater Energy Agriculture System (ISEAS) in order to investigate its energetic and environmental potential compared to conventional fuels.
Methods: We compare the hydroprocessed renewable jet fuel (HRJ) produced from ISEAS against fossil jet fuel using a life cycle assessment (LCA) methodology. Based on a detailed description of the production process, we use data from a wide-ranging literature review and experimental results from the specific location to make informed assumptions for the range of the process inputs and yields. We then analyze several process configuration scenarios with different ranges. Results and discussionISEAS can produce aviation biofuels, electricity, and food while afforesting coastal desert land, acting as a long-term sink for carbon, minimizing freshwater consumption, and having beneficial land use impacts when compared to fossil jet fuel production. Based on a sensitivity analysis, we show that ISEAS HRJ emits 38 to 68% less greenhouse gases than fossil jet fuel and yields an overall positive net energy balance under all scenarios except one with an extensive use of desalinated water.
Conclusions: ISEAS offers a promising pathway for integrating aquaculture and seawater agriculture in arid regions. It is essentially a process to sustainably augment aquaculture-based products by using its waste as a biofuel resource. Achieving positive emissions results depend critically on minimizing freshwater use, maximizing biomass yield and to a lesser extent the performance of biomass gasification.

Tags: bioenergy, halophyte, saline agriculture, integrated seawater agriculture, lifecycle assessment

Characterization of the Chemical Composition of the Halophyte Salicornia bigelovii under Cultivation.


Iwona Cybulska, Tanmay Chaturvedi , Ayah Alassali , Grzegorz P. Brudecki , J. Jed Brown , Sgouris Sgouridis , and Mette H. Thomsen. (2014) Energy & Fuels. 28 (6), pp 3873–3883 DOI: 10.1021/ef500478b. (Link)

Abstract: Straw of the halophyte Salicornia bigelovii was chemically analyzed for lignocellulosic components, extractives, and ash in relation to varying cultivation conditions (namely, irrigating water salinity and fertilizer grade). Irrigation water contained 10–50 ppt salt, and fertilizer application varied between 1 and 2 gN/m2. Composition of the biomass was comparable to traditional lignocellulosic biomasses, containing glucan (up to 27 g/100 g total solids (TS)), xylan (up to 23 g/100 g TS), and lignin (24 g/100 g TS), but also high amounts of ash (up to 53 g/100 g TS) and water–ethanol soluble extractives (up to 25 g/100 g TS). As most of the ash is extractable (up to 90%), a simple water wash is sufficient to bring the ash content down to a typical value found in the lignocellulosic materials. It was found that increasing water salinity used for the plant irrigation decreases lignocellulosic components content, increases ash content, and does not affect extractives content. The fertilizer application rate was not found to influence any of the responses, except for ash composition (lowering mineral content) and its amount in the flowering spike fraction. Stem and spike fractions were found to be significantly different in composition, with stems being closer to a typical lignocellulosic material.

Tags: bioenergy, halophyte, saline agriculture

A Land Suitability Study for the Sustainable Cultivation of the Halophyte Salicornia bigelovii: The Case of Abu Dhabi, UAE.

Yousef, L., W. al Yamani, S. Kennedy, S. Sgouridis. (2013) Arid Land Research and Management. Volume 27, Issue 4, 2013. DOI:10.1080/15324982.2013.771230. (Link)

Abstract: A land suitability study covering an area of 56,655 square kilometers was carried out for the cultivation of a halophytic bioenergy crop, Salicornia bigelovii, in the Emirate of Abu Dhabi using data collected from an extensive soil survey (scale of 1:100,000). Two simple limitation methods (referred to in the paper as the conservative and weighted methods) were used to interpolate soil map unit data for qualitative evaluation of the land. Land suitability was assessed based on a set of criteria developed in accordance with specific plant requirements and two policy scenarios regarding the use of arable land for saline agriculture. Both methods showed similar suitability outcomes, but the weighted method using weighted averages of soil components within a soil map unit produced more realistic results that reflect on the inherent heterogeneous properties of Abu Dhabi soils. Up to 69% of the examined land is found to be moderately suitable for S. bigelovii cultivation but the most suitable areas are located on the coastal zone of Abu Dhabi, and the most limiting factors are predominantly soil salinity and drainage.

Tags: bioenergy, halophyte, saline agriculture, simple limitation method


Aviation Industry’s Quest for a Sustainable Fuel: Considerations of Scale and Modal Opportunity Carbon Benefit.

Warshay, B., J. Pan, and S. Sgouridis. (2011) Biofuels, Volume 2, Number 1, January 2011 , pp. 33-58(26). (Link)

Abstract: Aviation biofuels require higher processing energy inputs than fuels derived from the same feedstocks used for land-based transport. This article investigates the tradeoffs in the decisions of feedstock and processing by introducing the opportunity carbon benefit metric for the resulting transportation service across modes. We evaluated combinations of feedstocks, processing methods, and transport system use between aviation and surface modes (i.e., pathways) for fuel yields, as well as the process energy and greenhouse gas emissions of several feedstocks to determine their opportunity carbon benefit. In the current conditions, gasification for electricity generation to power electric vehicles would lead to the highest transportation services. Taking into account process energy and the limited number of electric vehicles, diesel and ethanol pathways maintain a lead. Contrary to their relatively high transportation service yields, biomass-to-electricity conversion pathways fail to generate the opportunity carbon benefits of biomass-to-liquid pathways. Biomass-to-liquid pathways vary little, with the jet pathway having a slight disadvantage over the diesel option owing to its higher process energy needs. On the feedstock side, the marginal land feedstocks, such as salicornia and switchgrass, have the advantage over the process energy and cultivation energy inputs, despite their relatively lower per hectare yields.

Tags: Energy, biofuels, sustainable aviation, comparative


Solar-assisted Post-combustion Carbon Capture feasibility study

Mokhtar, M., M. T. Ali, R. Khalilpour, A. Abbas, N. Shah, A. Al Hajaj, P. Armstrong, M. Chiesa, and S. Sgouridis. (2011) Applied Energy. In press. doi:10.1016/j.apenergy.2011.07.032 (Link)

Abstract: Solvent-based Post-combustion Carbon Capture (PCC) is one of the promising technologies for reducing CO2 emissions from existing fossil-fuel power plants due to ease of retrofitting. A significant obstacle in widely deploying this technology is the power plant output reduction (Output Power Penalty – OPP) due to the energy intensive CO2 separation process. In this paper we propose and theoretically evaluate a system to reduce the OPP by providing part of the PCC energy input using solar thermal energy. It is hypothesized that reducing the OPP during the daytime coincides with peaks in wholesale electricity prices thus increasing the revenue stream for a solar-assisted PCC (SPCC) plant. The general framework for assessing and sizing an SPCC system is presented. A techno-economic assessment is performed as a case study for a 300 MWe pulverized coal power plant in New SouthWales, Australia using actual weather and wholesale electricity price data. It is shown that the proposed technology can be economically viable for solar collector costs of US$100/m2 at current retail electricity prices and optimal Solar load-Fraction (SF) of 22% (SF is the portion of solvent regeneration energy provided by solar energy). The convergence of increasing electricity prices and decreasing collector costs improves SPCC viability at higher SF.

Tags: Energy, CCS, techno-economic

Systematic comprehensive techno-economic assessment of solar cooling technologies using location-specific climate data

Marwan Mokhtar, Muhammad Tauha Ali, Simon Bräuniger, Afshin Afshari, Sgouris Sgouridis, Peter Armstrong and Matteo Chiesa. (2010) Applied Energy. doi:10.1016/j.apenergy.2010.06.026. (Link)

Abstract: A methodology for assessing solar cooling technologies is proposed. The method takes into account location specific boundary conditions such as the cooling demand time series, solar resource availability, climatic conditions, component cost and component performance characteristics. This methodology evaluates the techno-economic performance of the solar collector/chiller system. We demonstrate the method by systematic evaluation of 25 feasible combinations of solar energy collection and cooling technologies. The comparison includes solar thermal and solar electric cooling options and is extended to solar cooling through concentrated solar power plants. Solar cooling technologies are compared on an economic and overall system efficiency perspective. This analysis has implication for the importance of solar load fraction and storage size in the design of solar cooling systems. We also stress the importance of studying the relation between cooling demand and solar resource availability, it was found that overlooking this relation might lead to overestimations of the potential of a solar cooling system in the range of 22% to over 100% of the actual potential.

Tags: Energy, solar cooling, techno-economic, comparative



Sustainable Energy Transitions, Economics, Policy and Design


The Sower's Way: Quantifying the Narrowing Net-Energy Pathways to a Global Energy Transition


Sgouris Sgouridis, Denes Csala, and Ugo Bardi. (Open Access Link)

Abstract: Planning the appropriate renewable energy installation rate should balance two partially contradictory objectives: substituting fossil fuels fast enough to stave-off the worst consequences of climate change while maintaining a sufficient net energy flow to support the world's economy. The upfront energy invested in constructing a renewable energy infrastructure subtracts from the net energy available for societal energy needs, a fact typically neglected in energy projections. Modeling feasible energy transition pathways to provide different net energy levels we find that they are critically dependent on the fossil fuel emissions cap and phase-out profile and on the characteristic energy return on energy invested of the renewable energy technologies. The easiest pathway requires installation of renewable energy plants to accelerate from 0.12TW p /year in 2013 to peak between 6.6 and 10.4 TW p /year, for an early or a late fossil-fuel phase-out respectively in order for emissions to stay within the recommended CO2 budget.

Keywords: Renewable energy; Sustainable Energy Transition; Global pathways

RE-mapping the UAE’s energy transition: An economy-wide assessment of renewable energy options and their policy implications


Sgouris Sgouridis, Ayu Abdullah, Steve Griffiths, Deger Saygin, Nicholas Wagner, Dolf Gielen, Hannes Reinisch, Dane McQueen Renewable and Sustainable Energy Reviews, 1–15. http://doi.org/10.1016/j.rser.2015.05.039 (Link)

Abstract: We conduct a comprehensive mapping and cost analysis of the renewable energy (RE) technology options available to the United Arab Emirate’s (UAE) energy system. Based on projected demand and the true (unsubsidized) costs of fossil fuel supply, the substitution cost of each option and its respective potential is estimated. We demonstrate that a significant acceleration of the existing RE plans can be achieved with positive economic benefits for a number of options – before accounting for health and environmental benefits, or new opportunities for hydrocarbon exports – and that the full portfolio can be completed at a cost that is less than 1 US Dollar (USD) per gigajoule (GJ) when accounting for the avoided subsidies by 2030. Growing opportunity cost of gas, falling solar prices and abundant solar resources are the biggest drivers behind these results. Cumulatively implementation of these options results in RE contributing to 10% of UAE’s total final energy consumption in 2030. This achievement, seen in the context of the global effort to increase renewable energy penetration, is relatively limited, but the rates of increase in RE deployment are actually among the highest internationally given the low starting point and the unavailability of traditional RE sources (biomass and hydro) in the UAE. Moreover, they herald the implications of RE’s rapid shift to cost-competitiveness in a country like the UAE.

Keywords: Renewable energy; United Arab Emirates; Energy transition; Techno-economic assessment

A Framework for Defining Sustainable Energy Transitions: Principles, Dynamics, and Implications

Sgouridis, S. and D. Csala
Sustainability 20146(5), 2601-2622; doi:10.3390/su6052601 (Link)

Abstract: While partial energy transitions have been observed in the past, the complete transition of a fossil-based energy system to a sustainable energy one is historically unprecedented on a large scale. Switching from an economy based on energy stocks to one based on energy flows requires a social paradigm shift. This paper defines Sustainable Energy Transition (SET) and introduces a set of five propositions that prescribe its sustainability. The propositions are comprehensive, spanning environmental constraints, resource availability, equity, and the transition dynamics from an energy and economic accounting perspective aimed at addressing all three pillars of sustainability. In order to rigorously define the constraints of SET a theoretical energy economy framework is introduced along with the concept of the renewable energy investment ratio. The paper concludes with a practical application of the SET propositions on the global energy system and identifies an order of magnitude underinvestment in the renewable energy investment ratio in comparison to the estimated level needed for a controlled transition that satisfies all propositions. The option of drastically increasing this ratio in the future may not be available as it would reduce societally available energy, imposing unacceptably high energy prices that would induce either fossil resource extraction beyond the safely recoverable resources or energy poverty.

Open access model Link (developed by Denes Csala)

Keywords: sustainable energy transition, energy economics, renewable energy, system dynamics

A sustainable energy transition strategy for the United Arab Emirates: Evaluation of options using an Integrated Energy Model

Sgouridis, S., S. Griffiths, S. Kennedy, A. Khalid, and N. Zurita 
Energy Strategy Reviews, Volume 2, Issue 1, June 2013, Pages 8–18. SPECIAL ISSUE: Strategy Options and Models for the Middle East and North Africa (MENA) Energy Transition
doi:10.1016/j.esr.2013.03.002 (Link)

Abstract:      The United Arab Emirates (UAE), despite its small size, is emerging into an influential player in global energy geopolitics. Perhaps counter intuitively, the UAE can successfully leverage a sustainable energy transition to strengthen its position as a global energy leader while providing tangible economic and environmental benefits. To be executed successfully, a sustainable energy transition (SET) requires a careful consideration of available options but also political alignment and popular buy-in. The existence of significant energy subsidies on the demand side differentiates the option space as well as the benefit structure of fossil fuel rich states from other nations that have already progressed toward high penetration of renewable energy. A techno-economic assessment of SET options based on a novel Integrated Energy Model (EIEM) indicates that, under plausible assumptions for fossil fuel costs, the benefits of SET outweigh implementation costs.

Defusing the Energy Trap: The Potential of Energy-Denominated Currencies to facilitate a Sustainable Energy Transition

Sgouridis, S. (2014). Frontiers in Energy Research: Energy Systems and Policy. (Published Version Link, Older working version SSRN: Link)

Abstract:     The universal adoption of fiat currencies and of the fractional reserve banking system coincided with access to and ability to utilize energy-dense fossil fuels leading to unprecedented rates of economic expansion. The depletion of economically recoverable fossil fuels though sets the stage for systemic crises as it is not adequately priced in the current market system. An energy-based system of exchange can be adopted in parallel to or in place of fiat currencies in order to facilitate a sustainable energy transition (SET) and mitigate the impacts of such crises. Energy-backed and energy-referenced currencies are discussed as two possible variants for their ability to realign the economic system to the thermodynamic limits of the physical world. The primary advantage of an energy-referenced currency over the current mechanisms for SET (like feed-in tariffs or carbon taxes) is realized with the decoupling of the monetary and credit functions, especially when debt is tied to future energy availability. While energy-backed (credit) systems can be easier to adopt on a regional scale, the full transition to an energy-reference currency system requires significant reform of the financial and monetary system although it would not radically disrupt the current economic valuations given the high degree of correlation between value and embodied energy.

Keywords: energy currency, sustainable transition, energy economics, renewable energy, money supply

Tangible and fungible energy: Hybrid energy market and currency system for total energy management. A Masdar City case study.

Sgouridis, S. and Kennedy, S. (2010). Energy Policy Volume 38, Issue 4, April 2010, Pages 1749-1758, doi:10.1016/j.enpol.2009.11.049 (Link)

Abstract: We propose the introduction of an energy-based parallel currency as a means to ease the transition to energy-conscious living. Abundant fossil energy resources mask the internal and external energy costs for casual energy consumers. This situation is challenging communities that draw a significant fraction of their primary energy consumption from renewable energy sources. The Masdar Energy Credit (MEC) system is a way of translating the fundamental aspects behind energy generation and usage into a tangible reality for all users with built-in fungibility to incentivize collectively sustainable behavior. The energy credit currency (ergo) corresponds with a chosen unit of energy so that the total amount of ergos issued equals the energy supply of the community. Ergos are distributed to users (residents, commercial entities, employees, and visitors) on a subscription basis and can be surrendered in exchange for the energy content of a service. A spot market pricing mechanism is introduced to relate ergos to “fiat” currency using a continuously variable exchange rate to prevent depletion of the sustainable energy resource. The MEC system is intended to: (i) meet the sustainable energy balance targets of a community (ii) support peak shaving or load shifting goals, and (iii) raise energy awareness.

Tags: Energy, energy currency, ergos, renewable energy, economics

Rigorous classification and carbon accounting principles for low and Zero Carbon Cities

Kennedy, S. and S. Sgouridis (2011). Volume 39, Issue 9, September 2011, Pages 5259-5268, doi:10.1016/j.enpol.2011.05.038 (Link)

Abstract: A large number of communities, new developments, and regions aim to lower their carbon footprint and aspire to become “zero carbon” or “Carbon Neutral.” Yet there are neither clear definitions for the scope of emissions that such a label would address on an urban scale, nor is there a process for qualifying the carbon reduction claims. This paper addresses the question of how to define a zero carbon, Low Carbon, or Carbon Neutral urban development by proposing hierarchical emissions categories with three levels: Internal Emissions based on the geographical boundary, external emissions directly caused by core municipal activities, and internal or external emissions due to non-core activities. Each level implies a different carbon management strategy (eliminating, balancing, and minimizing, respectively) needed to meet a Net Zero Carbon designation. The trade-offs, implications, and difficulties of implementing carbon debt accounting based upon these definitions are further analyzed.

Tags: Energy, zero carbon, carbon accounting, urban design


Transportation Systems


Game Theory Analysis of the Impact of Single Aisle Aircraft Competition on Fleet Emissions

Morrison, J. K.D., R. John Hansman and Sgouris Sgouridis (2011). Journal of Aircraft. Accepted for publication.  
 
Abstract: To meet aviation’s CO2 emission reduction targets while maintaining mobility in the face of increasing effective fuel costs, technology innovation will be required. The single aisle commercial aircraft market segment is the largest by quantity and value, but has the longest running product lines. New aircraft programs offer the largest potential gains in fuel efficiency, but are risky and require large capital investments. Re-engining existing airframes reduces risk and capital requirements, but offers lower potential fuel burn improvements. Incremental improvements to existing aircraft lines may entail the lowest risk. It is hypothesized that competition has important effects on manufacturers’ decisions to innovate and that these effects must be considered when designing policies to reduce CO2 emissions from aviation. An aircraft program valuation model is developed to estimate expected payoffs to manufacturers under different competitive scenarios. A game theory analysis demonstrates how the incentives for manufacturers to innovate may be altered by subsidies, technology forcing regulations, increased effective fuel costs, the threat of new entrants, and long-term competitive strategies. It is shown that increased competition may result in incumbent manufacturers producing re-engined aircraft while increased effective fuel costs may result in new aircraft programs. Incumbents’ optimal strategies may be to delay the entry into service of new single aisle aircraft until 2020-24, unless technology forcing regulations are implemented.

Tags: Sustainable aviation, game theory, aviation industry competition

Air transportation for a carbon constrained world: Long-term Dynamics of Policies and Strategies for Mitigating the Carbon Footprint of Commercial Aviation

Sgouridis, S., P. Bonnefoy, and R. J. Hansman (2010). Transportation Research Part A: Policy and Practice. doi:10.1016/j.tra.2010.03.019 (Link)

Abstract: With increasing demand for air transportation worldwide and decreasing marginal fuel efficiency improvements, the contribution of aviation to climate change relative to other sectors is projected to increase in the future. As a result, growing public and political pressures are likely to further target air transportation to reduce its greenhouse gas emissions. The key challenges faced by policy makers and air transportation industry stakeholders is to reduce aviation greenhouse gas emissions while sustaining mobility for passengers and time-sensitive cargo as well as meeting future demand for air transportation in developing and emerging countries. This paper examines five generic policies for reducing the emissions of commercial aviation; (1) technological efficiency improvements, (2) operational efficiency improvements, (3) use of alternative fuels, (4) demand shift and (5) carbon pricing (i.e. market-based incentives). In order to evaluate the impacts of these policies on total emissions, air transport mobility, airfares and airline profitability, a system dynamics modeling approach was used. The Global Aviation Industry Dynamics (GAID) model captures the systemic interactions and the delayed feedbacks in the air transportation system and allows scenarios testing through simulations. For this analysis, a set of 34 scenarios with various levels of aggressiveness along the five generic policies were simulated and tested. It was found that no single policy can maintain emissions levels steady while increasing projected demand for air transportation. Simulation results suggest that a combination of the proposed policies does produce results that are close to a “weak” sustainability definition of increasing supply to meet new demand needs while maintaining constant or increasing slightly emissions levels. A combination of policies that includes aggressive levels of technological and operations efficiency improvements, use of biofuels along with moderate levels of carbon pricing and short-haul demand shifts efforts achieves a 140% increase in capacity in 2024 over 2004 while only increasing emissions by 20% over 2004. In addition, airline profitability is moderately impacted (10% reduction) compared to other scenarios where profitability is reduced by over 50% which pose a threat to necessary investments and the implementation of mitigating measures to reduce CO2 emissions. This study has shown that an approach based on a portfolio of mitigating measures and policies spanning across technology and operational improvements, use of biofuels, demand shift and carbon pricing is required to transition the air transportation industry close to an operating point of environmental and mobility sustainability.

Open access model Link (derivative model developed by Denes Csala)

Tags: Sustainable aviation; Environment; Carbon constraints; System dynamics modeling; Policy analysis

Simulation-based Analysis of Personal Rapid Transit System Implementation: Application in Masdar City Transportation System.

Mueller, K., and S. Sgouridis (2011). Journal of Advanced Transportation, doi: 10.1002/atr.158 (Link)

Abstract: Masdar City a zero-emission model city, is implementing a fully automated on-demand personal rapid transit (PRT) system for its intracity transportation needs. The car-sized electric vehicles will run on an underground road network transporting passengers and freight throughout the city. A discrete-event PRT simulation model (miPRT) is built to support the design and implementation of the first city application of this innovative system. Through simulation, we estimate the impact of different vehicle allocation algorithms, battery charging strategies and vehicle occupancy rates and anticipate the system's behavior under stress loads to rate its capacity limitations under travel demand surges due to special events as well as track close-down scenarios. The simulation model assists in improving fleet utilization, energy consumption, and overall system costs. Beyond the specifics of this implementation, this paper provides a tool for testing wider adoption of the PRT concept.

Tags: Personal rapid transit, discrete event simulation, transportation

Double Hull Phase-In in the Maritime Industry: The Effects of Sunk Cost and Uncertainty

Dikos, G., S. Sgouridis (2008). International Journal of Ocean Systems Management 2008 - Vol. 1, No.1 pp. 100 - 117. (Link)

Abstract: Following the Exxon-Valdez incident the, Oil Pollution Act was enacted by the US government in 1990 mandating double hull construction tankers operating in US coastal tankers. Traditional Cost Benefit Analysis to investigate whether this requirement is cost efficient does not include the timing of the implementation in anticipation of technological improvements or other system changes. We investigate the option value of waiting by applying the standard model for optimal timing of environmental policy (Pindyck, 2002) and extend it to accommodate irregular and extreme emissions. We demonstrate that neglecting the occurrence of extreme events can be misleading.

Tags: Shipping, real options, transportation, policy

New Approach to Transportation Planning for the 21st Century: Regional Strategic Transportation Planning as a CLIOS Process

Sussman, J., S. Sgouridis, and J. Ward. (2005). Transportation Research Record 1931 (2005), National Academy Press, Washington, DC. (Link)

Abstract: The complex large-scale integrated open systems (CLIOS) process is an overarching mechanism for considering systems, especially those exhibiting nested complexity, in which both the physical and the institutional aspects are complex. A special case of the CLIOS process is regional strategic transportation planning. New technologies, such as intelligent transportation systems, allow consideration of the planning, management, operations, and maintenance of transportation systems at the regional scale. Although the technological issues in advancing to this scale have proved tractable, the institutional issues concerned with deploying these systems across political jurisdictions with different measures of performance and different cultural perspectives has proved quite difficult. This paper explores processes for studying these institutional questions and integrating a number of concepts into the process: technological change, sustainability, real options, supply chain management, the various transport modes, and social, political, and economic factors. The paper serves as a case study of tailoring the CLIOS process into a process specifically designed to systematically address particular issues, in this case, regional strategic transportation planning.

Tags: Transportation planning, CLIOS, policy

Simulation Analysis for Midterm Yard Planning in Container Terminal

Sgouridis, S., D. Makris, and D. Angelides. (2003). Journal of Waterway, Port, Coastal and Ocean Engineering, Vol. 129, No. 4, July/August. (Link)

Abstract: The continuing growth of marine container transport and the complexity in the analysis of terminal port operations have resulted in a situation where computer simulation is mostly suited. This paper focuses on the simulated handling of incoming containers transported on trucks. It is applied on a medium-size terminal using an “All-Straddle-Carrier” system. Input data include parameters of space, speed, and arrival frequency in a generic format, thus making the model adjustable. Results on the service level, i.e., service times, utilization factors, and queues, are generated for analysis. The simulated system is used for short to midterm planning purposes, as well as a process improvement tool. A number of experiments provided the basis for evaluating case terminal performance and determining the potential for further operational improvements.

Tags: Shipping, container terminal planning, discrete-even simulation, modeling

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