Designing of an Emergency Energy Module for Relief and Refugee Camp Situations: Case Study for a

Refugee Camp in Chad-Sudan Border Sayedus Salehin, Huaichen Zhang, Tomas Larriba

Martinez, Giorgos Papakokkinos, Govinda Upadhyay, Eric Bowler

Department of Energy Technology Royal Institute of Technology (KTH)

Stockholm, Sweden sayedus@kth.se

Abstract- Each year thousands of people get displaced and are

forced to live in refugee camps or relief camps because of man­made or natural disasters. These people often lack basic needs such as clean water, lighting, cooling, etc. and many times these camps exist for more than 7-8 years. This paper aims at conceptualizing an Emergency Energy Module (EEM) which provides electrical energy to satisfy the basic needs and that can be deployed as an emergency response in a self-sufficient, self­contained, and highly mobile fashion, to support the energy demand of a refugee or a relief camp and the aid workers for long term. As a case study, a refugee camp near Chad-Sudan border has been investigated. As a preliminary study, electrical demand was determined for the camp. Further, locally available energy resources were studied and assessed based on key design criteria and the technologies were selected to meet the demand.

Polycrystalline Solar PV panels, micro wind turbine and biogas polyethylene digester and diesel generator were chosen as the technology to harness selected energy resources. HOMER Software has been used for optimization and techno-economic analysis of the energy system. The selected solution has been, then, analyzed from an operational point of view.

Keywords-energy module; hybrid system; emergency response; technoeconomic analysis;renewable energy

I. INTRODUCTION

Around 7 million out of 12 million refugees and asylum seekers have been living in camps for more than 10 years [1]. Along with this, thousands of peoples are forced to live in relief camps due to natural disasters e.g. earthquake, flood, volcanic eruption. In most of the cases, these people lack their basic needs namely clean water, lighting in the camp due to the absence of electricity. The aid workers often face problems due to unavailability of electricity and rely on diesel generators which require logistic support. The provision of a simple, robust, cost effective, and technologically feasible solution can significantly benefit the camp residents.

Few mobile energy supply units for disaster relief with varying configuration are available at present. Florida Solar Energy Center has developed a portable solar energy disaster kit [2]. Skybuilt Power has developed renewable energy station integrated in a standard shipping container [3]. Several

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J.M.N. van Kasteren Eindhoven Energy Institute

Eindhoven University of Technology Eindhoven, The Netherlands

studies have been conducted on the slzmg of wind­photovoltaic power generation system [4-6]. Work has also been conducted on the control and energy management of hybrid energy system based on renewable energy resources [7-8].

This paper presents a conceptualization of an Emergency Energy Module (EEM) for the supply of electrical energy in order to satisfy the basic needs of the people residing in the camps and the humanitarian agencies present there. The regular operation will be based on exploiting local renewable energy resources without sacrificing the reliability of the module. EEM will utilize a variety of local resources to produce a reliable supply of energy by reducing the camps' reliance on fossil fuels that are subject to high costs and complex transportation issues. As a case study, a hybrid energy system based on renewable energy resources for a refugee camp in Chad-Sudan border has been modeled and optimized using HOMER software [9].

II. PROBLEM DEFINITION

To design a flexible, mobile energy conversion unit that can be used in refugee camp condition for producing electricity using locally available energy resources for improving the quality of lives of the people residing in refugee camps and relief camps based on four criteria, i) Sustainability, ii) Reliability, iii) Flexibility and iv) Portability.

III. ENERGY DEMAND ANALYSIS

The basic need of the people in the refugee camp has been translated into electricity demand. The electricity demand for 20,000 people in the camp in Chad-Sudan Border has been calculated for lighting demand, administrative energy requirement for the humanitarian agencies, telecommunication energy demand for the aid workers, water purification demand, and vaccine cooling demand. Table I summarizes the total electricity demand in the relief camp modeled.

A. Lighting Demand

Lighting will be provided in common area of the refugee camps, hospitals, toilet areas, and offices. Total number of staff and area of the office has been calculated based on UN

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Standards [10]. A total area of 1760 sq. m is illuminated using Compact Fluorescent Light (CFL) bulbs.

B. Administrative Energy Demand

The electricity demand for the administrative work of humanitarian agencies working in the camp has been calculated. 50 laptops and 3 printers have been considered for the use in the administrative purpose and in the hospital.

C. Telecommunications demand

Three satellite phones have been considered for using in seeking information for emergency cases, contacting other organizations when help is needed, arrange logistic and civil issues, and for staff to communicate with their families. A commercial satellite phone consumes 50 W.

D. Water Purification Demand

Drinking Water requirement for a person is 2 liters/day [11]. Electricity demand for water purification using reverse osmosis technology has been calculated for the people in the camp as presented by Lachish [11]. 63. 75 kWh is consumed for serving the drinking water for the whole camp.

E. Vaccine Cooling Demand

One widespread and major issue associated with the quality of living in typical refugee camp environments is the proliferation of largely preventable diseases. The World Health Organization (WHO) estimates that in 2002 approximately 57 million people died from preventable diseases which could be avoided through vaccination. Of those 57 million people, approximately 10.5 million were children under the age of five. Vaccine cooling requirement has been calculated based on WHO guideline and work of Granryd et el. and Bansal et el. [12-13]. A total of 10 vapor compression, 10 platen munters cycle, and 2 thermoelectric coolers are recommended sized to store 20,100 vaccines at any given time.

TABLE I. TOTAL ELECTRICITY DEMAND

Electrical Demand (kWh/day) Peak Power

Cooling Water Lighting Admin, Telecom Total (KW)

18.8 63.8 52.1 22.1 0.63 157.4 8

IV. ENERGY CONVERSION TECHNOLGIES CONSIDERED

For the analysis of the module a wide variety of different energy generating technologies that are common in the market were investigated for their feasibility. Before optimizing the system, characteristics of the various technologies chosen are qualitatively analyzed.

A. Micro Wind Turbine

In most cases, there is lack of information about the wind potential of the site. Consequently, including larger wind turbines introduces the risk of burdening the EEM with heavier, larger, and more expensive equipment that will not contribute adequately to the electricity production. On the other hand, when the wind potential is proved to be significant more micro wind turbines can be included to scale up the electricity

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production. It is desirable to set up the refugee camps in non­windy sites, as the most common types of shelter are tents. Consequently, the wind speeds will be relatively low, something that brings attention to the cut-in speed. The cut-in speed is lower for micro wind turbines than small wind turbines and therefore, the micro wind turbine will operate more hours during a specific period (higher capacity factor) and in this way the intermittent behaviour of the wind will be mitigated to some extent.

B. Diesel Generators

Diesel generators have been globally deployed to satisfy energy demands for many years. Diesel is used in all types of situations from emergency relief, grid connected backup systems, to off grid base load generation. It is presently very difficult to compete with diesel on a levelized cost of electricity basis. The generators themselves benefit from economies of scale due to their mass production and competitive market saturation. This coupled their reliability for base load generation, provided fuel is readily available, will make diesel generators a necessary part of the emergency energy module.

The goal of the module then is to minimize the necessity of the generator operation. Diesel generators suffer from a major drawback, namely the use of diesel as the primary fuel. Geopolitical situations have illustrated the drawbacks of relying on fossil fuels for satisfying energy demand. In addition, with increasing scarcity of fossil fuel resources the cost of reliance will certainly increase. Long-term relief situations, such as refugee camps, are often located in remote regions where transporting fuel becomes a logistical difficulty and expensive. Through minimizing the emergency energy module's reliance on diesel generator operation the risks from the aforementioned drawbacks are also minimized and levelized costs of operation will in the long run be reduced.

C. Proton Exchange Membrane Fuel Cell

Although fuel cells have been developed for power production since 1950, the technology is yet to compete with its counterparts in terms of cost. It requires an energy carrier in the form of hydrogen along with all the associated components with regard to the production, monitoring, and storage of this carrier. However, the ability to produce clean energy from hydrogen and air is an attractive option. PEM fuel cells require pure hydrogen as the fuel input along with a steady flow of air [14].

Pure hydrogen is not a trivial matter because it has to be generated from water using an electrolyser and then stored. In addition, water might not be an available resource where the energy module is located as it might be required for drinking.

D. Photovoltaic Panels

Photovoltaic technology benefits from a high level of scalability. The equipment does not contain any moving part and thus less maintenance cost is required. Currently photovoltaic panels suffer from a high capital cost relative to other generation technologies. This cost has largely to do with materials and processing techniques. However, advancements in alternate material selection and simpler processing guarantee future price reductions and the increasing competitiveness of this technology [15]. Photovoltaic panels are very sensitive to

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fouling on their outer surface that would shade photons from interacting with the n-doped layer and reduce the power output of the device. Therefore, keeping the panels clear from sand and dirt is necessary for proper system operation and could prove a major difficult in a refugee camp environment.

E. Biogas Generator Set

The biogas generator set is composed of two subsystems: the digester subsystem and the generator subsystem. Biogas is produced from all kind of organic wastes [16]. This fact makes biogas utilization to have a double benefit, it creates a new energy source and it helps to solve a classical refugee camp problem: waste management and sanitation. Anaerobic digestion has a secondary product (digest) that could be used for agricultural purposes as fertilizer.

However, in this specific case, where human depositions are being used, the possible existence of bacteria in the digester, makes it less valuable and restrict its use for the non­edible crops. An appropriate technology is such that is designed with special consideration to the environmental, ethical, cultural, social, political, and economic aspects of the community for which it is intended. Regarding biogas generation in developing countries, the most widespread one is the polyethylene digester, due to its low capital and maintenance costs and its good performance in hot climates [17-18]. The only counterpart to this kind of technology is the impossibility to establish control systems that would optimize and regulate the biogas generation. This fact has a further implication, since not being able to have a perfect control of the digestion conditions (temperature, feed characteristics, pH, etc.) also means that oscillations in the biogas output would arise and it makes difficult to predict a daily production.

Producing biogas deals with social and cultural issues, since its row materials are human faeces and urine. In order to avoid problems related to social rejection, educational programs should be established by the refugee camp coordinator and special designs are considered (i.e. buried digesters).

F. Battery Storage

Utilizing intermittent renewable sources of energy will require an energy storage system to balance the demand and production of the system. Batteries have been employed in many applications over the years for this purpose and they have demonstrated the value of their technology. Different battery technologies have been developed however lead acid batteries are particularly interesting due to their specific power and cost characteristics. The lifetime of lead acid batteries tends to be problematic and is highly dependent on external conditions such as temperature, humidity, number of cycles, depth of discharge, rate of discharge, rate of changing, maintenance, etc. Lead acid batteries are well packaged and can easily be replaced and recycled with a developed infrastructure. However, the logistics of handling this considering a refugee camp aid will certainly be an important consideration.

V. ENERGY RESOURCES

The climate data for the case study of the refugee camp in the Chad-Sudan border have been assumed to be the same as the city of Abeche (13°48' N, 20° 48' E) which is located approximately 150 km away from the border (nearest location

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with available climate data). The data for Abeche (wind speed, solar irradiation, clearness index, temperature) have been introduced from the RETScreen model [19]. Scaled annual solar irradiation average of 6.39 kWhlm2/day and scaled annual wind speed average of 4 mls area available in the area considered.

Biogas generation from human waste and organic waste has been calculated based on works present in the literature [16]. The analysis regarding the biogas production has been approached conservatively. Following the calculations of the daily waste production, a collection factor has been applied in order to assure that the estimations of the collected waste are consistent with the conditions on a refugee camp. The collection factor has been set as 30% for urine, 50% for feces and 20% for organic waste. While taking into account the poor biogas production conditions, a safety margin has been also applied - namely, half of the estimated biogas production has been considered in the optimization procedure. Scaled annual average of 0.102 tons of biogas per day with 45.7% carbon content has been considered.

VI. SYSTEM DEFINITION AND OPTIMIZATION

The technologies under consideration have been assessed based on a series of factors which determined their applicability in the EEM. The pool of the approved technologies has been the basis for the construction of several scenarios for the EEM energy system. It has been considered crucial to analyze these energy system scenarios from a system's perspective. The importance of this analysis is to reveal the complex interaction between the energy generation technologies and the storage system, under the fluctuations of the resources potential.

HOMER software has been considered since it provides highly detailed technical and economical information about the energy system as the results of a techno-economic optimization. However, it should be noted that the optimization procedure has been treated in such manner as to assure that the results comply with aforementioned four key criteria. Since HOMER provides the optimum solution in terms of cost effectiveness, the key criteria have been applied either as constraints in the optimization procedure or through the post­processing of the results. Several technologies including trifuel engine, microturbine, hydrogen storage have been rejected after number of simulations in order to optimize the system. Table II shows the technologies considered for the modeling and simulation.

Fig. 1 shows the energy system model used for the optimization in HOMER. The economical and technical data used are collected from respective product websites [20-21]. The optimization result was analyzed using the criteria and system architecture has been proposed. The system architecture and the optimal energy mix by different components are shown in Table III and Table IV, respectively.

VII. BACKUP OPERATION

The EEM is also considered to be equipped with a diesel engine for the backup operation in case of a failure of the biogas generator or inadequate biogas production. A sensitivity analysis has been undertaken in order to determine

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the diesel usage as a function of the biogas production. From this analysis, it has been revealed that the estimated biogas production, which is required to operate the module exclusively by RES, is achievable.

TABLE II. TECHNOLOGIES USED IN OPTIMIZATION

Capacity Cost Lifetime O&M Note [$/ 0.05 Rated

7kW 2300 3000h $/h efficiency Biogas 15%

Engines 0.05 Rated 9kW 3000 3000h $/h efficiency

20% 7$/y Rated

Photovoltaic 0.23 kW 653 20 years Efficiency 13.8%

1.2kW 5529 15 years 55 $/y

2.4kW 11996 20 years 120

Wind $/y

Turbines 4kW 20319 20 years 203 $/y

5kW 30756 20 years 307 $/y

0.01 PEMFC

Fuel Cells 5kW 20495 40000h $/h Rated efficiency

45% Hydrogen I kg H2 1500 25 years 15

Storage $/y

Electrolyzer IkW 2000 15 years 20 $/y

0.05 Rated Trifuel 5.5kW 2650 2000h $/h efficiency Engine 13%

(biogas) 0.02 Rated

Microturbine 5kW 6000' 10000h $/h efficiency 12%

Diesel 5kW 2500 15000h 0.05 Engine $/h

Rated Voltage:4

Batteries 1900 Ah 1346 10569 4 V kWh $/y Stack: 6

batteries (24V)

a. Capital Cost predicted for 10000 units/year production

Also, the information provided by this sensitivity analysis can be used to predict the diesel demand as a function of the biogas production and arrange the logistics of the fuel accordingly. Fig.2 illustrates the relation between the diesel demand in hours (yellow) and the renewable fraction (green) as a function of the biogas production.

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� Toilet

9.6 kWh/d 1.2 kW peak

I-----+l.....--.� .!J rn_ TeLCool_ Wa

138 kWh/d 7.1 kW peak

}Jclon 1.2kW -wi ...

tJ .E!J Converter S4KS25P

AC DC

Figure I. Energy system model in Homer

TABLE III. SYSTEM ARCHITECTURE

PV Array 5.75 kW Wind Turbine 9 Cyclon 1.2 kW

Biogas 7kW

Battery 12 Surrette 4KS25P

Inverter 8.4kW

Rectifier 7.56kW

Dispatch Cycle Charging Strategy

TABLE IV. OPTIMAL ENERGY MIX

Technology kWh/yr %

PV Array 9,860 16

Wind Turbine 16,770 28

Biogas 33,497 56

Total 60,127 100

VIII. ECONOMIC ANALYSIS

For the calculation of the Net Present Cost (NPC), the annual real interest rate is set to 6% and the project lifetime to 20 years. Fig.3 shows the net present cost of the optimized energy system. For the optimized energy system, Total NPC is calculated as $170,087, Levelized Cost of Electricity (LOC) as $0.275/kWh and operating cost as $6,738/year by HOMER. NPC of the system and Nominal Cash flow of the components are shown in Fig.3 and Fig.4, respectively.

IX, LOCATION FLEXIBILITY

It has been determined which components will be comprised in the EEM, but the amount of each component will be decided after a site-specific analysis. In order to examine the flexibility of the EEM, another location has been chosen for sensitivity analysis. This location is Comodoro Rivadavia in Argentina, which has much higher wind potential and lower solar potential relatively to Chad -Sudan border.

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0.12 0.14 0.16 BiOS"S Produclion (lid) 0.18

0.9.g

.£ "

0.8 :0

0.7

0.6 0.20

" � " � '"

Figure 2. Biogas production influence over diesel usage and renewable fraction

X. LOCATION FLEXIBILITY

It has been determined which components will be comprised in the EEM, but the amount of each component will be decided after a site-specific analysis. In order to examine the flexibility of the EEM, another location has been chosen for sensitivity analysis. This location is Comodoro Rivadavia in Argentina, which has much higher wind potential and lower solar potential relatively to Chad -Sudan border.

f'V

1 00,0100 +-------------- 1 = �����/.2kW -with price info

- Surrette 4KS25P

Capital Operatin g Fuel

- Converter

Salvage

Figure 3. Net present Cost of the system

o PV

50.000 0 C�clon 1.2k W • BIOgas7

Surrelte 4KS25P • onvcncr

Cash Flow

o - ... - ... - .. - . . - ..

-;; 'gSO.ooo o

Z

-100.000

o I 2 3 4 5 6 7 8 9 10 II 12 13 14 15 16 17 18 19 20 Year Number

Figure 4. Nominal Cash flow of the components

As observed in Fig.5, the energy share does not vary significantly. This arises from the fact that the main energy source is biogas, which is not site-specific. The biogas production as well as the electricity demand is proportional to the refugee camp population. Consequently the variation in the energy system of the EEM will be influenced exclusively by

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the wind and solar potential. In order to see the variation of the energy system, a sensitivity analysis has been undertaken in respect to the wind and solar potential as seen in Fig.6.

XI. SYSTEM OPERATION

The system optimization provided a well defmed energy system including wind turbines, photovoltaic modules, a biogas production system and generator and batteries. HOMER software provides with hourly information of the system behavior under different conditions and loads. Fig.7 and Fig.8 are samples of two days where the same load demand has to be satisfied, but the available resources are very different. In a windy day, the high wind resource allows the system to shut down the biogas generator, increasing its lifetime. However, in a sunny day in summer with almost nonexistent wind resource, the system reacts using the biogas generator to satisfY the demand.

Energy Production [%) 60.0 -,----------------

50.0

40.0

30.0

20.0

10.0 • Chad

0.0 • Comodoro

Biogas Wind Solar

Figure 5. Comparison of energy production in Chad-Sudan Border and Comodoro Rivadavia

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8

"C 8.6

Vl "C " �

4

5 olar (kWh/mlday) Figure 6. Sensitivity Analysis

Another conclusion that can be extracted from Fig.7 and Fig. 8 is the order of preference to generate the energy at any moment. Wind and solar resources will be used when available. In the case of overproduction, batteries will be charged if possible. When both together are not able to produce energy enough, then batteries will be used and, in the last case, the biogas generator will be switched on. Sometimes the system running on biogas will charge the batteries in order

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to achieve around 80% charging level (optimal set point) as can be seen from Fig.8.

�lS .----------------Wind�y�D�a�y-------------------

10

-5�------------------------------------------

Battery outputiiiiilPV iiiiilCycion1.2kW Bioga, Genset - AC Primary Load

Figure 7. System Operation during a windy day

� 15 Sunny Day

� � II 11 '1

] 1 � 1 1 � �

10

5

o

L .. U -5

SotteJyoutput PV Cyelon 1.2kW Siogo, Gen,et - AC Primary Lood

Figure S. System Operation during a sunny day

XII. LOGISTICS

Due to the availability of standard shipping containers and their ease of transportation using trucks, lorries, ships and other means of transport, is considered for transporting the components of the system to the desired location. This container can be used as operation center at the location after all the components are installed at their respective places. A standard 20 feet Dry Freight Shipping Containers having a Pay Load of 28,280 kg (6.05 x 2.44 x 2.59 m) has been considered for this purpose.

XIII. CONCLUSION

The conceptual design of an Emergency Energy Module has been presented along with its techno-economic analysis for a refugee camp situated in Chad-Sudan Border with a population of 20,000 people. This design can be implemented in other refugee camp scenarios with modification necessary for the location. The system presented has been assessed with the viability of using it in refugee camp situation. Also, the backup operation, location felxibility and system operation has been presented. Further investigation of this concept is required for the development of EEM.

ACKNOWLEDGMENT

This paper is an outcome of Project of the Year 2010-2011, Erasmus Mundus Masters in Environomical Pathways for Sustainable Energy Systems (SELECT) at KTH. The authors express their gratitude to SELECT Program director Dr. Viktoria Martin (KTH) for her guidance and advice throughout

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the project and also to Dr. Massimo Santarelli (Politecnico Di Torino), Dr. Anders Malmquist (KTH), Ms. Rigmor Argren (Save the Children Foundation, Sweden) for their valuable suggestions.

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