Search results

1 – 10 of 142
To view the access options for this content please click here
Article

Xiang Li and Ziyou Gao

Regenerative braking is an efficient energy saving technology in urban rail system, in which the recovery energy from braking trains is collected by some equipments and…

Abstract

Purpose

Regenerative braking is an efficient energy saving technology in urban rail system, in which the recovery energy from braking trains is collected by some equipments and released to accelerating trains when needed. However, the high cost and low lifetime of storage devices prevent the widespread use of this technology. The purpose of this paper is to conduct thorough cost-benefit analysis to facilitate China’s urban rail companies to make decisions on the use of such technology.

Design/methodology/approach

To evaluate the benefit from regenerative energy storage, the authors formulate an improved integrated scheduling and speed control model to calculate the net energy consumption associated with different energy recovery rates and then define the benefit as the amount of energy saving arising from the usage of storage equipments. With the frequent charge/discharge operations on storage equipments, the energy recovery rate generally decreases which lowers the benefit, but the maintenance cost increases. By trading-off benefit and cost, the authors derive the optimal scrapping time, the maximum profit and the profitability condition for storage devices.

Findings

Simulation studies based on the Beijing Metro Yizhuang Line of China are given. The results show that compared with the current timetable and speed profile, the integrated scheduling and speed control approach with energy recovery rate of 0.5 can reduce the net energy consumption by 12.69 per cent; the net energy consumption can be well approximated as a linear function of energy recovery rate; and the maximum profit and the optimal scrapping time on regenerative energy storage devices are both positively related to the electricity price. The allowance proportion and the number of service trains such that busy lines with higher electricity price or allowance proportion have advantages to use the regenerative energy storage devices.

Research limitations/implications

In this work, a linear energy recovery rate and a linear maintenance cost are used in the cost-benefit analysis process. In future research, the more accurate expressions on energy recovery rate and maintenance cost should be considered if more data on recovery rate and maintenance cost can be gathered.

Originality/value

The main values of this paper are to develop the integrated optimization approaches for train scheduling and speed control and, on this basis, make thorough cost-benefit analysis for regenerative energy storage to improve the operations management of urban rail transit.

Details

Chinese Management Studies, vol. 11 no. 1
Type: Research Article
ISSN: 1750-614X

Keywords

To view the access options for this content please click here
Article

Hugo Neves de Melo, João P. Trovão, Carlos Henggeler Antunes, Paulo G. Pereirinha and Humberto M. Jorge

The purpose of this paper is to present a prospective study of sustainable mobility in the framework of a supporting energy management systems (EMS). Technological…

Abstract

Purpose

The purpose of this paper is to present a prospective study of sustainable mobility in the framework of a supporting energy management systems (EMS). Technological advances are still required, namely electric vehicles (EV) endowed with improved EMS in order to increase their performance by making the most of available energy storage technologies. As EVs may be seen as a special domestic load, EMS are proposed based on demand-sensitive pricing strategies such as the Energy Box discussed in this paper.

Design/methodology/approach

The study presents an overview of electric mobility and an urban EV project, with special focus on the utilization of its energy sources and their relation with the energy demand of a typical urban driving cycle. Results based on the ECE 15 standard driving cycle for different free market electricity tariffs are presented.

Findings

The analysis based on present Portuguese power and energy tariffs reveals that it is highly questionable whether the resulting profit will be enough to justify the potential inconveniences to the vehicle user, as well as those resulting from the increased use of batteries.

Practical implications

The conclusions indicate that more studies on the trade-offs between grid to vehicle and vehicle to grid schemes and electricity pricing mechanisms are needed in order to understand how the utilization of EVs can become more attractive in the end-users’ and utilities’ perspectives.

Originality/value

The paper proposes an approach for future electricity tariff behavior that could be applied to EVs in order to understand whether or not their grid integration in charge and discharge situations would be beneficial for end-users and utilities, in the framework of smart energy management technologies.

Details

Management of Environmental Quality: An International Journal, vol. 26 no. 4
Type: Research Article
ISSN: 1477-7835

Keywords

To view the access options for this content please click here
Article

Chin Tachia and Liu Ren-huai

This paper aims to introduce ten studies included in this themed issue that illustrate from multifaceted angles some critical management issues and context-specific…

Abstract

Purpose

This paper aims to introduce ten studies included in this themed issue that illustrate from multifaceted angles some critical management issues and context-specific challenges on strategy and innovation facing the State and enterprises during China’s socio-economic transition. Instead of focusing on topics from the literature, this special issue (SI) pays more attention to characterising unique Chinese business practices in the transformation period.

Design/methodology/approach

The ten manuscripts were selected for this SI so that readers can compare how scholars used different research designs and multiple analytical and statistical approaches to draw conclusions.

Findings

These studies involve a wide range of aspects, as well as diversified perspectives demonstrating some critical management issues and context-specific phenomenon associated with the development of strategy and innovation in contemporary China. The results show that while pollution-related issues have had a damaging effect on China’s business environment, the Chinese government has to enact and enforce stricter environmental laws to promote technology innovation in a healthier manner; moreover, Chinese firms should pay greater attention to the trade-off between the increasing of resource consumption for growth and the reducing of energy use for the sake of the planet. In response to the grand innovation challenges Chinese manufacturing is confronted with, these papers suggest that policy support may not always be beneficial but sometimes detrimental to independent innovation, and that Chinese manufacturers may ultimately get access to the key and core technology of forerunners by forming a R&D strategic alliance in periphery knowledge/technology first. Overall, the outcomes of these studies provide a bigger picture and intriguing implications that may inspire practitioners, policymakers and academics to further ponder relevant issues in a more comprehensive way.

Originality/value

All ten studies based on original data were not reported elsewhere and demonstrated results that have not been addressed in prior research. This paper enriches one’s understanding of how Chinese firms have been deliberately seeking their own distinctive trajectories of developing strategy and innovation dissimilar to those of advanced economy companies, given the peculiar cultural background and institutional systems. Future research trends and opportunities are also outlined.

Details

Chinese Management Studies, vol. 11 no. 1
Type: Research Article
ISSN: 1750-614X

Keywords

To view the access options for this content please click here
Article

Roya Bonyad, Mahdi Hamzenejad and Mohammadali Khanmohammadi

The purpose of this paper is to propose a hierarchically structured system of regenerative architecture indicators for assessing research-educational building projects.

Abstract

Purpose

The purpose of this paper is to propose a hierarchically structured system of regenerative architecture indicators for assessing research-educational building projects.

Design/methodology/approach

First, based on a literature review of the historical roots of regenerative design and related approaches and the interviews held with experts of the related field, the paper proposes a structured framework of architectural indicators suitable for the context of Tehran. Later, the importance of criteria is estimated by the analytic hierarchy process method based on a survey of experts. Finally, the results clarify the order of indicators’ importance for enhancing research-educational buildings with the aim of developing regenerative design in the context.

Findings

The rankings revealed that, in the environmental dimension, “Design of site & building” and “Site & context considerations” are the top priorities of learning spaces in Tehran followed by “Water management,” “Energy management” and “Materials & waste management” ranked as less significant, but still important indicators. In the social dimension, “Design for people & human health” was considered much more important than “Social interaction” and “Interaction with nature,” and in the cultural dimension, “vernacular & historical features of design” was more important than “Aesthetic feature.” In the economic dimension, “Energy storage & production” indicator was ranked highest followed by “Adaptability & multiplicity of design solutions” and “Using waste to produce new resources.” Generally, for achieving regenerative architecture in learning spaces, the environmental criterion was given the highest weight among all dimensions. After that, the higher rank was given to social dimension; while cultural and economic dimensions took the third and fourth place.

Research limitations/implications

The paper has limitations because of the limited number of experts in the field of regenerative approach.

Originality/value

This research seeks to answer the following question: what is the ranking of regenerative architecture indicators in the design of research-educational building projects in the context of Tehran? To answer this question, the indicators of regenerative design in the architectural field are explored through a detailed study of literature and interview with experts of the related field; later, they are ranked based on a survey approach that investigates the opinions of experts. The final results are then explained based on logical analysis to obtain a comprehensive understanding. The prioritization of indicators actually provides a simple framework for designers and architects to have a clear path in developing an architectural regenerative project when different contexts vary in influential features. The selection and prioritization of indicators in this research depended mainly on their relevance to the conditions of Tehran and can be used for regions with similar conditions as well.

Details

Smart and Sustainable Built Environment, vol. 9 no. 1
Type: Research Article
ISSN: 2046-6099

Keywords

To view the access options for this content please click here
Article

Steven Liaros

Whilst the energy transition from fossil fuels to renewables offers significant environmental benefits, the other transition – from a centralised to a distributed energy

Abstract

Purpose

Whilst the energy transition from fossil fuels to renewables offers significant environmental benefits, the other transition – from a centralised to a distributed energy system – underpins a disruptive model for planning cities, towns and villages. A local energy micro-grid can power a local water micro-grid, which in turn can irrigate a local food system, offering a community the opportunity to harvest, store and distribute food, water and energy within their immediate catchment. A distributed network of regenerative villages, connected virtually and with shared electric vehicles is offered as an alternative vision for future cities. The paper aims to justify this as a preferred model for human settlements and develop an implementation process.

Design/methodology/approach

This paper asks: Is it inevitable that large cities will keep growing, while rural communities will continue to be deprived of resources and opportunities? Is the flow of people into cities inevitable? To answer this question, the adopted methodology is to take a systems approach, observing town planning processes from a range of different disciplines and perspectives.

Findings

By contrasting the current centralising city model with a distributed network of villages, this paper offers ten reasons why the distributed network is preferable to centralisation.

Research limitations/implications

It is argued that in this time of dramatic technological upheaval, environmental destruction and social inequality, business-as-usual is unacceptable in any field of human endeavour. This paper presents a sketch outlining a new human settlement theory, a different way of living on the land. It is an invitation to academics and practitioners to participate in a debate.

Originality/value

The information and energy revolutions, both distributed systems, are reshaping cities.

Details

Smart and Sustainable Built Environment, vol. 9 no. 3
Type: Research Article
ISSN: 2046-6099

Keywords

To view the access options for this content please click here
Article

Marek Michalczuk, Bartlomiej Ufnalski and Lech M. Grzesiak

The purpose of this paper is to provide high-efficiency and high-power hybrid energy source for an urban electric vehicle. A power management strategy based on fuzzy logic…

Abstract

Purpose

The purpose of this paper is to provide high-efficiency and high-power hybrid energy source for an urban electric vehicle. A power management strategy based on fuzzy logic has been introduced for battery-ultracapacitor (UC) energy storage.

Design/methodology/approach

The paper describes the design and construction of on-board hybrid source. The proposed energy storage system consists of battery, UCs and two DC/DC interleaved converters interfacing both storages. A fuzzy-logic controller (FLC) for the hybrid energy source is developed and discussed. Control structure has been tested using a non-mobile experimental setup.

Findings

The hybrid energy storage ensures high-power ability. Flexibility and robustness offered by the FLC give an easy accessible method to provide a power management algorithm extended with additional input information from road infrastructure or other vehicles. In the presented research, it was examined that using information related to the topography of the road in the control structure helps to improve hybrid storage performance.

Research limitations/implications

The proposed control algorithm is about to be validated also in an experimental car.

Originality/value

Exploratory studies have been provided to investigate the benefits of energy storage hybridization for electric vehicle. Simulation and experimental results confirm that the combination of lithium batteries and UCs improves performance and reliability of the energy source. To reduce power impulses drawn from the battery, power management algorithm takes into consideration information on slope of a terrain.

Details

COMPEL: The International Journal for Computation and Mathematics in Electrical and Electronic Engineering, vol. 34 no. 1
Type: Research Article
ISSN: 0332-1649

Keywords

To view the access options for this content please click here
Article

Zongyun Song, Jian Zhang, XInli Xiao and Dongxiao Niu

To improve power system peak dispatching ability, connecting energy-storage device such as electric vehicle (EV) and regenerative electric heater (REH) to power grid is a…

Abstract

Purpose

To improve power system peak dispatching ability, connecting energy-storage device such as electric vehicle (EV) and regenerative electric heater (REH) to power grid is a good choice.

Design/methodology/approach

This paper establishes a multi-energy combined peak dispatching system MCPDS which includes EV, REH and wind power. The matter-element extension model based on improved variable weight theory is applied to evaluate MCPDS synthetic benefit.

Findings

The research shows that the MCPDS established in this paper performs excellently in security benefit, economic benefit, social benefit and environmental benefit.

Originality/value

With the assistance of energy storage devices such as EV and REH, the electrical system peak dispatching ability and power system operation efficiency has improved. More devices with energy-storage ability should be introduced into electrical power system to improve its synthetic benefit.

Details

International Journal of Energy Sector Management, vol. 13 no. 3
Type: Research Article
ISSN: 1750-6220

Keywords

To view the access options for this content please click here
Article

N. Baldock and M.R. Mokhtarzadeh‐Dehghan

Aims to present a methodology for analysing a solar‐electric, high‐altitude, long‐endurance, unmanned aircraft.

Abstract

Purpose

Aims to present a methodology for analysing a solar‐electric, high‐altitude, long‐endurance, unmanned aircraft.

Design/methodology/approach

The study focuses on the aerodynamics, flight performance and power requirements of a heavier‐than‐air, solar‐electric, HALE UAV. The methodology is founded on using an analytical approach to determine the power required to undertake various flight manoeuvres. An analytical approach is also undertaken in determining the intensity of the solar radiation available to the aircraft. Finally to demonstrate the methodology, a HALE concept was generated and evaluated.

Findings

When using estimates of current solar‐electric propulsion and energy conversion efficiencies, the HALE concept was only able to sustain year round, level flight up to latitudes of 10°N.

Research limitations/implications

Further analysis needs to be undertaken into the effect of altitude on the intensity of solar radiation, which could be as much as 25 per cent higher at an altitude of 21.3 km (70,000 ft). Further study into this subject area may provide proof that sustained flight is possible at more northerly latitudes.

Originality/value

This paper provides a simple methodology for persons wishing to undertake an initial feasibility study of a solar‐electric HALE concept.

Details

Aircraft Engineering and Aerospace Technology, vol. 78 no. 3
Type: Research Article
ISSN: 0002-2667

Keywords

To view the access options for this content please click here
Article

Joseph Hitt, Thomas Sugar, Matthew Holgate, Ryan Bellman and Kevin Hollander

The purpose of this paper is to describe a project which seeks to develop a new generation of powered prostheses based on lightweight, uniquely tuned, energy‐storing…

Abstract

Purpose

The purpose of this paper is to describe a project which seeks to develop a new generation of powered prostheses based on lightweight, uniquely tuned, energy‐storing elastic elements in series with optimal actuator systems that will significantly reduce the peak power requirement of the motor and the total system energy requirement while providing the amputee 100 percent of required “push‐off” power and ankle sagittal plane range‐of‐motion comparable to able‐bodied gait.

Design/methodology/approach

This paper presents the design, power, and energy‐efficiency analyses, and the results of a five‐month trial with one trans‐tibial amputee subject as part of the first phase of the Spring Ankle with Regenerative Kinetics project.

Findings

The data show that by leveraging uniquely tuned springs and transmission mechanisms, motor power is easily amplified more than four fold and the electric energy requirement is cut in half compared with traditional approaches.

Originality/value

This paper describes an energy efficient, powered transtibial prosthesis currently unavailable commercially. Motor power and energy requirements are reduced with use of a unique design that employs regenerative kinetics.

Details

Industrial Robot: An International Journal, vol. 36 no. 5
Type: Research Article
ISSN: 0143-991X

Keywords

To view the access options for this content please click here
Article

Montserrat-Ana Miranda, María Jesús Alvarez, Cyril Briand, Matías Urenda Moris and Victoria Rodríguez

This study aims to reduce carbon emissions and costs in an automobile production plant by improving the operational management efficiency of a serial assembly line…

Abstract

Purpose

This study aims to reduce carbon emissions and costs in an automobile production plant by improving the operational management efficiency of a serial assembly line assisted by a feeding electric tow vehicle (ETV).

Design/methodology/approach

A multi-objective function is formulated to minimize the energy consumption of the ETV from which emissions and costs are measured. First, a mixed-integer linear programming model is used to solve the feeding problem for different sizes of the assembly line. Second, a bi-objective optimization (HBOO) model is used to simultaneously minimize the most eco-efficient objectives: the number of completed runs (tours) by the ETV along the assembly line, and the number of visits (stops) made by the ETV to deliver kits of components to workstations.

Findings

The most eco-efficient strategy is always the bi-objective optimal solution regardless of the size of the assembly line, whereas, for single objectives, the optimization strategy differs depending on the size of the assembly line.

Research limitations/implications

Instances of the problem are randomly generated to reproduce real conditions of a particular automotive factory according to a previous case study. The optimization procedure allows managers to assess real scenarios improving the assembly line eco-efficiency. These results promote the implementation of automated control of feeding processes in green manufacturing.

Originality/value

The HBOO-model assesses the assembly line performance with a view to reducing the environmental impact effectively and contributes to reducing the existent gap in the literature. The optimization results define key strategies for manufacturing industries eager to integrate battery-operated motors or to address inefficient traffic of automated transport to curb the carbon footprint.

1 – 10 of 142