Benchmarking Energy Management Systems for UAE Metro Stations – A Framework

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International Journal of Emerging Technology and Advanced Engineering

Website: www.ijetae.com (ISSN 2250-2459,ISO 9001:2008 Certified Journal, Volume 5, Issue 10, October 2015)

280

Benchmarking Energy Management Systems for UAE Metro

Stations – A Framework

Samira Rajabi

1

_{, Salwa Beheiry}

2

1_{Graduate Student, Engineering System Management Masters Program, The American University of Sharjah, Sharjah, UAE} 2_{Assistant Professor, The American University of Sharjah, Sharjah, UAE}

Abstract—Energy and environmental sustainability have become central objectives in mobility system design and mass transit schemes. In addition to environmental prudence, a new world economic order calls for a more efficient use of financial resources. The purpose of applying energy management in Metro stations is to reduce the amount of energy use throughout every phase of the stations’ project life cycle, including construction and facility operation, in order to have the least possible negative effect on the long-term well-being of our planet. An energy management system should follow the hierarchy of reducing energy demand, using energy efficiently, and then sustaining the remaining essential energy demand with cleaner energy sources. This paper is the first step in a multiphase research effort to develop a “best in class” benchmarking model for metro stations. It lays the groundwork for developing a benchmarking system to measure the utilization of energy management techniques in United Arab Emirates (UAE) metro stations. Hence, the preeminent technologies in energy management will be reviewed and related to metro stations use in hot climates. This “best in class” benchmarking model, among other design criteria, will examine hybrid geothermal heat pumps for the ventilation systems, Fiberglass insulation, and a full-closed type platform screen doors. Additionally, technologies such as special LED lighting to reduce energy consumption and Flywheel Kinetic energy storage will also be assessed. Finally, the potential use of Photovoltaic energy sources in the proposed benchmark facility is studied, to provide clean energy sources for heating, lighting, and ventilation uses.

Keywords— Benchmarking; Energy Management; Metro

stations; Infrastructure; UAE

I. INTRODUCTION

A metro system is considered as a rapid transport system and sometimes referred to as subway or underground. A metro system involves both passenger carriages and disembarking station buildings to facilitate passenger access and exit. There were approximately 160 metro systems in the world at the end of 2010. A metro system is defined as an electric passenger transport system having a high rate of services and a high capacity (Wright 2010).

The difference between Metrorail and other types of public transport, such as light rail and commuter rail, is not always clear. But metro systems typically derive from Metropolitan transit systems, referring to metropolitan or modern cities. A metro system in contrast to light rail system almost runs on a grade-separated exclusive right-of-away without any contact with traffic and pedestrians. Besides, metro systems do not have any common track with freight trains and inter-city rail services.[1]

London was the first city to have an underground mass transit line. It was opened in 1890. The initial power supply introduced in London metro was steam. Later, the first electrified metro opened in the United States, city of Boston. Since then, 116 countries in Europe, America, Asia, Middle East and North Africa have opened their own metro system in the main cities. Although the investment cost is relatively high, the potential for metro systems development is still considerable because of the rampant overpopulation of cities.

A Metro system is one of the most effective transport systems in terms of space occupancy and energy consumption. Metro networks were used to transport virtually 155 million passengers per day worldwide to their destination in 2006. The figure shows that the number of passengers in metro systems was 34 times the average daily number of air passengers at the same period. This highlights the social and economic importance of developing and operating a metro system.

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International Journal of Emerging Technology and Advanced Engineering

281 These systems include Bangkok (Thailand), Caracas (Venezuela), Mexico City (Mexico), Madrid (Spain), Tunis (Tunis), and Recife (Brazil) [1].

The initial capital costs of metro systems (stations, routes and carriages) depend mostly on the price of building materials and labor, planning institutions and permitting procedures, geological conditions, as well as the extent of grade separation needed and right-of-away arrangements. Research shows that effective planning procedures usually increase capital costs dramatically as they mandate design that is more careful in addition to high quality assessment in each stage of development of the rail system.

Traditionally, ground conditions (whether it is underground construction or it is bridge foundation), urban restrains such as environmental constrains, water table depth for selected area, safety and design constrains factors have large influence on capital cost Furthermore, some other assessments factors affect rail-based systems’ capital costs in capital European cities. For instance, new Installations vary in cost from progressive development of existing systems. On the other hand, some aspects have a marginal influence on growth of capital costs such as labor, Taxes and duties and system features such as air conditioning. [2] Nonetheless, modern management policies enhance the organization quality and financial efficiency of the systems. Operating costs include maintenance, fuel, salaries….etc. The required services by a metro car determine the operation costs. As operating services increase, the circulation time and number of cars needed for single line decrease. There are three main categories for operation costs; per vehicle Hours, per passenger trips and per vehicle revenue per km.

Presently, energy and environmental sustainability are predominant objectives in mobility system design. As energy falls within both the economic and the environmental dimensions of sustainability, it’s related economic efficiency should be ensured. In fact, for an economically prudent system, it is essential to demonstrate a high level of energy-efficiency. With economic growth, transport demand has increased in the case of European Union (EU) in recent years. [2]

Energy Management Systems (EMSs) are strategy management practices that require a methodical approach to achieve the maximum energy savings in a building design. The process includes energy conservation, energy efficiency, and off grid renewable resources tapping system; with co-generation and natural gas being viewed as slightly loftier than hydrocarbons and fossil fuel sources of energy (the least desirable).

Figure(1): The present situation of energy consumption in China. [9] The transport activity index in the European Union is responsible for nearly 30% of total energy consumptions and 27% of total greenhouse gas emissions. This is relative to a GDP index that rose by more than 50 percent from 1990 to 2014 and it is expected to increase to by another 30% or 35% by 2030 for passenger transport. [2]

Furthermore, the energy consumption in the European union had a uniform rate of 1000 million TEP in the agriculture sector. Energy consumption in the industrial sector is on the decline reporting a decrease from 6000 million TEP in 1990 to 4000 million TEP in 2004. In the services sector, the energy consumption maintained a uniform rate and remains at 1000 million TEP from 1990 to 2014. Domestic transportation is the only sector reporting and increase in energy consumption over a comparable period. It rose from 2000 million TEP to 5000 million TEP from 1990 to 2004. [2] In China on the other hand, the energy consumption is much higher in the industrial sector. Please see Figure 1. [9]

A. Energy Management Systems in Buildings and Infrustructure

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282 Furthermore, the rapid increase in oil price and its vulnerable supplies makes the situation more risky. Energy Management systems (EMSs) help mitigate the risks associated with the continued high demand for grid energy and the growing dependence on mass transit systems in congested cities.

According to Miranda and Silva (2012), there is a need for a significant change in the current transportation systems to increase equity, economic efficiency, and environmental safety. A sustainable transportation system is defined as a system that can positively contribute to the economic and social status of a country without having any negative effect on human health and the environment. While considering the social, economic, and environmental aspects, the system can be integrated to:

a) Satisfy the necessities and needs of access and movement of the entire society.

b) Choose the transport modes that have acceptable costs, function efficiency, and offer to support a dynamic economy for regional development.

c) Develop the renewable resources at a rate below or equal to their regeneration and utilization rates of renewable substitutes and reduce sound emission and land use as much as possible. (Miranda,H&Silva,A, 2012)

On the other hand, there are two factors determining the energy demand for integrated transport systems which are first of all, the source of energy, and secondly the consumption of energy in each transportation sector. Fossil Fuel is the main energy-type demand. Other types of energy, such as natural gas and coal are consumed at lower levels. In essence, the world total transportation related energy consumptions has increased dramatically in recent years totaling almost one-third of the total energy consumption in the developed countries. (P, 2008)

Missaoui, et al, in the 2012 article entitled ―Managing energy Smart Homes according to energy prices‖, attests that buildings with advanced energy management system (BEMS) are actually smart buildings having strategies and ideas to reduce the total energy needed for both construction and maintenances and providing users with a more comfortable living environment. The aim of this system was to enhance the ease, comfort, and security of the users while reducing the energy consumption and related waste. Energy management systems provide a method, which controls the consumption of energy by proposing new techniques to match the energy production with consumers need.

The two main objectives for using EMSs are to improve the energy efficiency and reduce the Green Gas emissions. EMSs typically fall into two categories; predictive and real time control models.

The predictive control model uses predication models to measure the data that is used to find the best strategy for energy management in buildings; while the real time control data will implement its system by applying the sophistic mode to find the best energy management strategy to control consumption of energy in buildings. The real time control models also use predictive techniques by establishing the real time algorithms without forecast of price. The aim of these models is to encourage the users to control load peaks in order to decrease Peak–to-Average Ratio (PAR). (P, 2008)

Metro rail systems consist of passenger carriages and disembarking stations, the focus of this research as mentioned earlier, will be the metro station buildings, because a large portion of energy is consumed in buildings. Approximately 32% of total consumption of the energy in the world is attributed to buildings and indoor living habitat consumption, in addition to 36% of green house gas emissions. Furthermore, Cal, et al, in their article ―China building energy consumption: Situation, challenges and corresponding measures‖ state that the energy consumption of buildings is increasing by more than 10% yearly in China. The total national consumption of the energy by 2004 was about the 20.7% in buildings. (P, 2008)

The data on energy consumption in china by building type shows that public buildings are approximately 26 % of total energy consumption. Public facilities are defined as areas with a gross floor area more than 20,000 m2_{. The}

paper proceeds to state that there is a need for creating high-energy efficiency in China’s public buildings using a series of strategies that include:

a) Strong management and supervision of new government projects to instigate design with energy management in mind.

b) Energy consumption reduction in existing public building by strong Demand Side Energy (DSE) management in public areas.

c) More powerful system installation to encourage energy conservation in building.

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283 Another approach to reduce grid energy consumption in buildings is to use renewable energy sources. Solar energy, ground heat pumps, and photovoltaic power generation are the main sources of renewable energy that are sensible for metro stations use. (W.G.Cal;Y.Wu;Y.Zhong;H.Ren, June,2009)

Missaoui, et al, (2012) also explains an advanced Building Energy Management system (BEMS) as a system that brings new strategies and methods for reduction of energy consumption as well as providing better comfort levels for residents and users. The aim of these systems is to enhance the ease, comfort, and security of the users while reducing the energy consumption. Energy management system provides a system, which controls the consumption of energy by proposing new techniques to match the energy production with consumers needs.

B. Energy Management Systems in Hot Enviroments

Desert-prone hot and humid climates present a challenge for enrgy management. Air conditioning is an overwhlming portion of energy conomption to create habitable envrionments for work and leisure. Without the synthetic weather adjustment techniques and gear, it is very difficult to sustain a comfortable indoor envrionemnt conducive to work and healthy living. This, offocurse, applies to UAE buildings and enclosed environemnts. Yet, the initial design of a building can still contribute to an imporved energy efficiency in the long term usage of the building.

Recently, more attention is being paid to Demand Side Energy (DSE) management, which means controlling the consumer demand by applying various incentives and techniques to trigger the users to reduce their energy consumption. This is facilitated by some EMSs that focus on HAVC (heat, ventilation, and air conditioning) and electrical water heaters. The HAVC systems can be considered as a mechanical design of a thermodynamic nature, with fluid mechanics and heat transfer for indoor environmental comfort. Since HVAC systems constitute a major portion of energy consumption in UAE enclosed environments, DSE could constitute a plausible approach for further integration in metro stations energy-benchmarking methodologies. One of the techniques that this article is proposing for energy management is the Photovoltaic power sources (PV) method. In the PV method, semiconductors will be used to convert the solar radiation directly into current electricity for generating the electrical power using the solar panels in roof or

underground of the buildings.

(W.G.Cal;Y.Wu;Y.Zhong;H.Ren, June,2009).

There is an emerging trend towards energy management in the UAE. A realization has hit, at both governmental and social levels, regarding energy costs and possible ways to make energy use more efficient. The UAE has considerable potential resources such as petroleum and gas, compared to its small population.

It is considered as one of the biggest exporting countries for petroleum byproducts, yet energy awareness is rising, with energy regulations to follow. The mounting inclination to regulate such policies should have two applicable results. First, it will direct the country towards cleaner production schemes and be one of the leader’s in the Energy Management Systems sectors. Secondly, it will inspire organizations to design with sustainable energy in mind. (Nazli Choucri, 2011) Additionally, Abu Dhabi is trying to save latent resources such as fossil fuel reserves for future generations by investing in the renewable energy market, to meet today energy demand and possible future rise in local demand.

The emirate of Abu Dhabi, the ruling capital of the UAE, and the seat of government, defined and spearheaded the new energy policies. The essence of the outlook is to move toward a symmetric system for renewable energy and secure 7 % of the energy demand by using more renewable energy resources by the year 2020. Moreover, possible strategies are explored to balance the production of energy, using both renewable, and hydrocarbon resources. (Masdar Clean Energy , 2014) Nevertheless, according to Choucri (2011), the renewable energy policy in UAE would be effective if the mere regulations become essential operational systems in all governmental organizations in the UAE. Moreover, energy efficiency should not only be seen as a basis of projects validity, but also a strategy for better energy management in every aspect of UAE projects. (Nazli Choucri, 2011)

Presently, lighting systems, air conditioning, heating, and power tools are the main energy consumers in modern buildings. According to Peng Xu, energy management systems in building should address following aspects:

1-Improve the thermal insulation in buildings via door and window openings, cladding and wall systems.

2-Improve the HVAC and lightening systems’ efficiency (cooling, heating, ventilation, etc.)

3-Enhance energy controls in all buildings zones 4- Expand the use of renewable energy sources

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International Journal of Emerging Technology and Advanced Engineering

284 This document is template. We ask that authors follow some simple guidelines. In essence, we ask you to make your paper look exactly like this document. The easiest way to do this is simply to download the template, and replace (copy-paste) the content with your own material.

II. METHODOLGY

This study is a first stage framework conception to benchmark EMSs use in UAE metro stations. The ultimate research goal is to create a ―Best in Class‖ metro station in terms of energy efficiency, conservation, and management. Albeit, the focus of this paper is three first two steps, the remaining steps below would amalgamate into a metro station benchmark that can be used to plan for new metro stations’ projects and assess existing stations, in the area, for retrofitting.

1.Review the broad literature on energy management systems.

2.Consider the energy management needs of the UAE and related climatic conditions.

3.Study the existing energy management techniques in current metro stations.

4. Explore emerging strategies and technologies in energy conservation and management

5.Tailor an energy conservation and management system to UAE Metro Stations; create a ―best in class‖ benchmark

The Purpose of the Metro stations analysis step is mainly to assess the existing energy systems or practices in metro stations. The proposed modified model would include several alterations as seen in figure 2. Moreover, the following section will provide sample of six recommendations for specific design materials and systems in the ―Best in Class‖ benchmark station.

Figure(2): Modified energy management system in metro stations (created for the purposes of this research study)

C.“Best in Class” Model Elements

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285 Figure(3): Minimum thermal resistance of insulation

In this study, 700 series fiberglass insulation is recommended for insulation in the model ―Best –in- Class‖ metro station. The 700 series is made of inorganic glass fiber with thermosetting resin binder [8]. Some encouraging features of the fiberglass 700 series include: 1-Energy efficient- can reduce energy demand and heat

transmission.

2-Non-destructive nor structurally intrusive- does not trigger adjoining materials’ damage and preserves the structural reliability.

3-Sound proof- can reduce or dampen sound transmission. 4-Light weight- controls dead loads on structures

5-Easy to handle - the 700 series is easy to handle, install, and assemble on site.

2) Solar Systems: In hot environments with unremitting sunshine like the UAE, utilizing solar energy to power buildings is a prudent choice. Yet, the choice of solar devices can be tricky. A solar energy photo-thermal system has two key systems: active and passive. Passive systems are easier systems because they are independent of additional devices for heat transfer.

The design of the building should be considered carefully before deciding on a solar energy strategy. For best efficiency from solar radiation systems, elements such as the selection of building’s materials, layout, interior spacing, and exterior setting, are crucial.

On the other hand, active systems are more complex and relatively higher in cost compared to passive systems. For full functionality, additional gear such as solar heating kits and power assemblies are needed. (Li Yang , Bao-jie He ,*, Miao Ye , 2014).

In passive solar-powered system, solar energy can be received into two different forms, heat storage wall and direct-gain. The key element in solar heat storage is windows. For instance, it is important to use large windows, and double-glazed low emissivity glass in cold areas.

However, in the UAE, the weather is extremely hot and humid from May to October. Thus, it is very important to put up elements such as sun shading boards to prevent entrance of solar radiations to overheat interiors. There are many shading boards’ options in the market with varying characteristics.

Figure (4) shows a typical thermal heat storage technique for a south wall with double deck glass curtain cover. An air layer is formed between the wall and the glass cover. (Li Yang , Bao-jie He ,*, Miao Ye , 2014) Once the heat is received from solar radiation through the glass layer of the wall, it will be evenly transferred to the interior surfaces of the building.

Figure (4): Solar system power wall (Li Yang , Bao-jie He ,*, Miao Ye , 2014)

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International Journal of Emerging Technology and Advanced Engineering

286 Solar radiation is received through external solar heating and power collection equipment in this system. These panels are usually placed on the roof and side slopes of the building. As it is shown in figure (5), this specific system is composed of two fans: a collector and a heating fan. Both of them run concurrently to circulate air through the thermal energy collector. These two fans can also be used as an outlet solar collector to provide hot water. For summer days, when heat transfer into the building is not desired, an electric fan can be used to further control the airflow. A thermal storage room should be used in this system to collect and store the heat for future demand. In sunny days, solar energy can be collected and stored. While the electric fan and the heating fans are switched off, the collector fan will be turned on to gather the heat from the solar radiation and the hot air will flow on to the heat store room until it reaches its maximum storage capacity.

In the cooler days, the heating and electric fans are switched on. The cold air inside the building flows through the gravel layer in the heating room and the warmer air will be transferred inside the building. When the heating system is not needed for the building, the solar collector can used to supply the hot water for bathrooms and retailers use. (Li Yang , Bao-jie He ,*, Miao Ye , 2014)

Figure(5): Solar heating system for providing hot water in summer (Li Yang , Bao-jie He ,*, Miao Ye , 2014)

3) Platform Screen Doors: Platform screen doors can be used for as both a passenger safety measure and a temperature control mechanism inside a metro station. The safety aspect has been addressed in many ways, including open and closed screens.

Recently, the concerns of loading and unloading passengers safely in a metro station have been viewed more seriously. Several metro stations use a simple platform with stairs attached to it to allow travelers to ascend up to a coach in order to board. Other transport systems, such as the London tube, built up platforms about the same height of the metro floor offering easier access to the coaches. An increase in use of metros and deploying better safety approaches, sustainability awareness, and many other factors have forced the metro designers to develop a system that would separate passengers form the rail track and the train physically.

This system contained fixed barriers or sliding powered doors and is referred to as a Platform Screen Doors (PSD) system. One of the main PSD functions is to protect passengers on the platform from falling onto the rail track, but they also help in temperature control tool for metro station buildings.

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287 Figure(6): Two types of platform screen doors (PSDs). (a) Mobile

full-height (MFH) and (b) mobile half-full-height (MHH). [21]

PSDs control climate and reduce energy consumption by preventing loss of air into train tunnels. There are three types, namely Full-Closed, Semi-Closed (Platform Edge Doors or PED) and Half Height.

As seen in Figure 6a above, Fully Closed PSDs provide total separation between the track and the platform, hence controlling the climate and providing enhanced safety. In addition, the humid air existing in the tunnel is prevented from entering the station leading to reduction in cooling load and hence reducing energy consumption. Moreover, enclosed PSDs detach the platform from the dust, heat and air blast generated by train movement (Melvyn THONG, 2012)

As seen in Figure 5a, there is complete separation between the rail track and the platforms with Platform Edge Doors (PED). However, they are Semi Closed and hence do not completely seal between the rail track and the station. Although PEDs are of the Full Height type and provide enhances safety, they are not meant to control climate nor prevent air loss in the stations and that is the main difference between these and the fully enclosed PED system.

4) Flywheel Energy Storage: Energy storage is an important conservation venue to be taken into account when dealing with railway systems.

The energy storage devices are mainly used to enhance poor voltage regulation and improve efficiency by capturing the energy generated by brakes in trains. Energy devices that are stored on board the trains reduce the acceleration currents by providing an additional power source yielding in reduction in voltage sags (Szénásy, 2009). This benchmarking framework contemplates the use of Flywheel technology as a type of energy storage device. Flywheels consist of a disk rotating around an axis which storages kinetic energy in from of angular momentum (Bradbury, 2010). The energy generated by motors when a train brakes is lost to the environment as heat. A flywheel device, which is deployed next to the track, collects and stores this lost energy as from kinetic energy (Williams Grand Prix Engineering Limited). Flywheel releases the energy stored via electrical cables to the motors once the train is about to move away which results in a power boost (Williams Grand Prix Engineering Limited). When adding the energy (charge) the speed of flywheels increases and decreases during discharge (Bradbury, 2010). Flywheel devices are characterised as below:

 Low Speed (less than 10000 rpm): usually made of considerably heavy disks. These types of flywheels could have either vertical or horizontal shafts and consist of magnetic bearings

 High Speed (above 10000 rpm): since these types operate at higher speed they require stronger materials such as composites of graphite or fibreglass in order to avoid failure. For the same reason, they must have vertical shaft and magnetic bearings.

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International Journal of Emerging Technology and Advanced Engineering

288 That would lead to electrical networks voltage reduction and less power (Williams Grand Prix Engineering Limited).Further advantages of the flywheel system includes (Oberhofer):

 Long lifespan  Low maintenance

 Environment friendly (almost no carbon emission)  Fast response times

 Improved reliability and performance The main drawbacks of such systems include:

 High acquisition costs  High self-discharge  Low storage capacity

5) Innovative Lighting Systems: Lighting systems are another important factor that needs to be taken into considerations when dealing with metro station design. Lighting system of metro stations is the main source of power and energy consumption and they have a relatively high initial and maintenance cost. Moreover, metro stations operate for very long hours, including many hours after sunset. They are also designed and constructed with many parts underground, lacking vital access to natural light. This increases the demand side for integrated and innovative lighting systems. Lighting is also a vital part of the basic architecture of most metro stations and it should be in line with design requirements of the location. Lighting should be efficient, easily maintained and durable.

Light Emitting Diodes or LEDs are the most common lighting solutions used in residential and commercial spaces. They are more energy efficient than other systems and tend to have longer lifespans. The main drawback of LED is its relatively high initial and renewal cost but this is compensated by much lower energy usage (Ticket to Kyoto, 2013).

The Paris Metro systems (RATP) started recently to retrofit their stations with LED lighting. Authorities are planning to be the first transport network to use LED lighting 100 percent of the time. It is estimated that lighting power consumption is responsible for 19% of total energy consumption at RATP (RATP France). Planners at RATP forecast that switching the current lighting system to LED lamps should decrease the energy consumption and related greenhouse emissions by 50% across their networks. Furthermore, lighting products manufacturers, such as Schréder, offered a lighting upgrade solution to Brussels metro stations using ASTRAL LED lamps that proved to decrease the energy consumption by almost 50%.

It also reduced the greenhouse emission (CO2) by

approximately 20 tonnes per year (Shreder, 2014). A report by Linda Sandahl et. al for the US Department of Energy provides the following reason for using LED lighting systems in commercial buildings (Linda Sandahl, 2009):

 Energy saving

 Better total system efficiency  Enhanced luminary optical efficiency  Control capability

 Decreased maintenance cost  Enhanced uniformity  Environmental friendly

6) Hybrid Geothermal Heat Pump: Hybrid Geothermal Heat Pump (GHP) systems can be used as a thermal energy source and a heat sink for heat pumps. In hybrid GHPs, reduction happens in the ground heat exchanger size and the auxiliary heat rejecter is used to handle the excess heat rejection load during the building cooling process.

At a depth of 3-4 feet underground, the soil strata is both warmer and cooler than the ambient air during peak cold and hot seasons. This facilitates cooler and hotter temperatures, respectively, in condensation and evaporation processes. This leads to improved energy efficiency and increases the cooling and heating capacity at extreme temperatures that could reduce or even eliminate the need for auxiliary heating. (Assessment of Hybrid Geothermal Heat Pump Systems, 2011)

For short-run investments, GHPs may not be the ideal cooling system. This is especially true for commercial buildings in climates such as the UAE, where cooling is more needed than heating. The advantage of using GHP is its energy and cost saving attributes in the long term.

These systems operate more efficiently than the conventional ones, since the geothermal source temperatures are much more stable than those of ambient air. In addition, geothermal sources have more consistent temperatures; with less severe fluctuations in highs and lows over study periods compared to outdoors air. Moreover, in GHP systems less energy is used and energy consumption patterns is reduced which yields in reducing cost and saving money. (Assessment of Hybrid Geothermal Heat Pump Systems, 2011)

III. CONCLUSION

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289 It develops the basic theoretical framework for a measurement system to benchmark and ultimately standardize the degree of use of energy management techniques in the United Arab Emirates (UAE) metro stations. The existing literature and research on energy management in buildings and infrastructure was reviewed and integrated with techniques for energy management in hot and humid climates like the UAE.

Several suggestions were made regarding the design elements to be ultimately included in a ―Best in Class‖ benchmarking model. These recommendations include Hybrid Geothermal Heat Pumps (HGHP) for the ventilation systems, Fiberglass insulation, Photovoltaic technology, and a Full-Closed type platform screen doors. Furthermore, LED lighting technologies and Flywheel Kinetic Energy Storage are also considered as part of the proposals to reduce energy consumption and improve efficiency.

Further research will focus on case studies of existing energy management techniques in current metro stations, followed by further exploration of emerging strategies and technologies in energy conservation and management. This should lead to a tailored system to be used in as a reference for new metro station projects and to retrofit existing stations.

IV. RECOMMENDATION

The authors started pursuing the second stage of this research; including the local stations data gathering and class A benchmark creation. It is recommended that further research should explore benchmarks for different climatic conditions and different rail options. This should lead to improved financial efficiency in these transportation projects, and encourage further development in the infrastructure sector in many developing and developed countries.

Acknowledgments

The authors would like to thank Prof. Li Yang in College of Architecture and Urban Planning, Tongji University, China; Bao-Jie He in the School of Environment and Architecture, University of Shanghai for Science and Technology, China; Miao Ye in School of Environment and Architecture, University of Shanghai for Science and Technology for their cooperation in this paper.

REFERENCES

[1] L. Wright, "Transport Policy Advice," Module 3a Mass Transit Option, vol. 19, no. 44, pp. 1-19, 2001.

[2] Carmen,F,Y.―Electric Power system Reserch,‖ Energy Management in metro-transit system , vol. 12, no. 81, pp. 2127-2138, 2011.

[3] Miranda,H*,"Transport Policy," Benchmarking sustainable eurban mobility , vol. 11, no. 21, pp. 141-151, 2012.

[4] P. P, "Transportation Research Part A," The effect of transportation policies on energy consumption, no. 42, p. 901–909, 2008. [5] Rim Missaoui, " Analysis of a Building Energy Management

System," Managing energy Smart Homes according to energy prices, pp. 155-167, March,2014.

[6] Nazli Choucri, "IEEE International Workshops on Enabling Technologies:Infrustructure for Collabroative Enterprises," Modeling Renewable Energy Readiness: The UAE Contecxt , vol. 11, pp. 211-216, 2011.

[7] "Masdar Clean Energy," Masdar , 2014. [Online]. Available: http://www.masdar.ae/en/media/detail/abu-dhabi-investing-in-an-evolving-world-energy-market.

[8] W.G.Cal*, "China building energy consumption," Situation, challenges and corresponding measures, pp. 2054-2059, June,2009. [9] Li Yang *, "The application of solar technologies in building

energy," BISE design in solar-powered residential buildings, pp. 111-118, 2014.

[10] Bo Yuana,Corresponding author contact information, E-mail the corresponding author, Shuqiang Dingb, Dongdong Wanga, Gang Wanga, Hongxia Lia, "Material Letter," Heat insulation properties of silica aerogel/glass fiber composites fabricated by press forming, vol. 75, pp. 204-206, 2012.

[11] P. Connor, "Platform Protections Systems: A review of platform/train interface protection systems on railways," Railway Technical Webpages, 2011.

[12] A.C. Melvyn THONG, "Energy Efficiency in Singapore’s Rapid Transit System," pp. 38-46, May 2012.

[13] I. Szénásy, "New Energy Management of Capacitive Energy Storage in Metro Railcar by Simulation," Acta Technica Jaurinensis, vol. 2, no. 1, 2009.

[14] K. Bradbury, "Energy Storage Technology Review," 2010. [15] Williams Grand Prix Engineering Limited, "Energy Storage for Rail

Applications," Williams Grand Prix EngineeringLimited,[Online].Available:http://www.williamsf1.com/ AdvancedEngineering/Stationary-Flywheel-Systems/Energy-Storage-for-Rail-Applications1/. [Accessed 3 June 2014].

[16] A. Oberhofer, "Energy Storage Technologies & Their Role in Renewable Integration".

[17] Ticket to Kyoto, "SAVING ENERGY IN METRO AND LIGHT RAIL STATIONS," Ticket to Kyoto, 12 Decemer 2013.[Online].Available:

http://www.tickettokyoto.eu/sites/default/files/downloads/4-Saving%20energy%20in%20metro%20and%20light%20rail%20stati ons.pdf. [Accessed 3 June 2014].

[18] Peng Xu PhD P.E.*, "Institute for building energy," Effectiveness of energy retrofit methods in public building in China , pp. 1-71, Mrach,2012.

[19] A. Oberhofer, "Energy Storage Technologies & Their Role in Renewable Integration".

[20] Bo Yuana, Corresponding author contact information, E-mail the corresponding author, Shuqiang Dingb, Dongdong Wanga, Gang Wanga, Hongxia Lia, "Material Letter," Heat insulation properties of silica aerogel/glass fiber composites fabricated by press forming, vol. 75, pp. 204-206, 2012.