COST ANALYSIS OF RENEWABLE ENERGY FOR POWER SUPPLY FOR REMOTE AREA IN YEMEN : A CASE STUDY FOR SOCOTRA ISLAND

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1 COST ANALYSIS OF RENEWABLE ENERGY FOR POWER SUPPLY FOR REMOTE AREA IN YEMEN : A CASE STUDY FOR SOCOTRA ISLAND Saqqaf A. Alkaf, Mohammed A. Muqbel and Salem M. Bin Qadhi + Mechanical Engineering Department, Faculty of Engineering, University of Aden, Yemen + smbinghdi@gmail.com Abstract Yemen has vast Renewable Energy Resources ( Solar, wind, geothermal, tidal ) available for energy generation through renewable energy technologies. Continuous efforts are being in progress by the government of Yemen with the help of several international agencies, resulting in starting several renewable energy pilot projects. Most of the earlier published research works on renewable energy were devoted on data analysis and few dealt with renewable energy applications. In this paper, cost analysis study of renewable energy application for rural Yemen, is carried out. Yemen territory includes many islands extending over 2500 km long coast, the largest of which is Socotra Island. Socotra is an island following province of Hadhramout and considered as one of the most beautiful tourist area with biodiversity and cultural significant attractions which has been declared as an environmentally protected island. Socotra enjoys high wind speed in the range of 5-12 m/s and monthly daily solar radiation ranges from 8 18 MJ/m 2 which are considered as high potential for renewable energy applications. In this study, the Socotra weather data were taken from Metrological Department, Aden Airport, Yemen. Electrical load data was based on a typical households of the island. Wind turbine data were taken from manufacturer's catalogues. In conclusion the wind turbine application in Socotra Island was found to be the most suitable and cost effective than other sources. This study would be extended successfully to other Islands in Yemen such as Kamaran, Hunaish,,etc. It is better to use Wind/PV combination system when wind turbine cost is suitable to give low overall unit of energy price. Keywords: Wind Energy, Hybrid System, Socotra Island 1. Introduction Socotra is part of an archipelago, but all the other islands are small. The largest of these are Abdul Kuri and the Al-Ikhwan Islands. The largest island, also called Socotra, is about 95% of the landmass of the archipelago. Socotra is part of the Republic of Yemen. It is an island following province of Hadhramout. it has an area of about 3,600 square km and considered as one of the most beautiful tourist area with biodiversity and cultural significant attractions which has been declared as an environmentally protected island. It has been described as the most alien-looking place on Earth [1]. Figure 1. Show the map of Yemen and the location of the Socotra island. The islands stand on coral banks. The interior of the island is dominated by the beautiful and green mountains called Hajhir, rising up to 1,503 meters above sea level. The Hajīr (Hajhir) Mountains occupy Socotra s interior, with narrow coastal plains in the north and a broader plain in the south, the north is the most inhabited part. The Island has about 70,000 inhabitants (2008 estimate). The Island suffers from shortage of electrical power supply. The available power supply confined to the limited diesel or petrol generators. The island remains isolated from the other parts of Yemen during high wind speed during the months of May up to September, which make transport for fuels diesel and petrol more difficult. The status of electrical energy production in Yemen rely on Steam power plants and diesel power plants. The diesel operated power stations constitutes about 50% of the electrical energy, the rest is supplied by steam power plants. Prices of the electric energy is highly effected by the increase of the imported diesel fuel. The significant of installing wind turbines in the Island can efficiently meet the growing electricity demand, while providing a merits of free and widely available clean source, no air, soil or water pollution. generation. WE: Wind Energy 1

2 Figure 1- Map of Yemen, and the location of Socotra island. Wind power is taking off in a big way worldwide, in both giant utility-scale installations and smallscale turbines intended to power a single home [2]. Remote off-grid dwellers are finding wind power an excellent supplement to solar during cloudy weather, and enjoying the extra freedom that more power input gives, especially after dark or during cloudy weather. In the other hand falling oil production, rising gas prices, and global climate change will encourage the growing interest in wind power. The Island has a good potential of solar and wind energy resources. But till now there has no such activity to use these resources. HOMER software, has been used to find out the best energy efficient renewable system for the Island. [3]. Analysis has been done for central wind turbines generators and wind/solar hybrid system as well as for a single home user of PV system to get the most economical and technical viable options. Limited resources of recent measured data regarding the wind potentiality in the island. More data for the wind potentiality in the island were obtained from meteorological department [4]. All these various sources of data ensure the potentiality of wind energy in the island. Analysis of these data declare that, the wind speed is in the range of 6-12 m/s which is considered as a high potential value. 2. Wind Energy Turbine Selections The monthly mean values for the wind speed for the years ( ) is illustrated in Fig. 2. It is clear the that the wind speed exceed 12 m/s in the months (July to September). While a minimum values were recorded in (February- April) months. Based on this data the annual mean speed at Socotra is found 8.23 m/s. Homer Software was used to illustrate the behavior of the wind scheme in a typical day time. Figure 3 shows typical wind fluctuations in day time scale using Homer software. While Figure 4. Illustrate the daily mean of wind speed in a typical day in July. Table 1 shows the assumption for the load demand for a single household in Socotra. An average energy consumption of 1400 Wh/day is needed. In this paper, three different types of wind machines were considered for electrification of Socotra: small size, two fixed blades, pitch controlled; model Fortis-Boreas. medium size and of big size all are of models WES 18 and WES 80. These are both twin bladed upwind machines using computerized yawing systems and power control to ensure maximum energy capture at all times. The evaluation of the energy output of the three proposed machines has been conducted. Using the given wind distribution for Socotra and with the help of the characteristics and parameters of a wind generator. WE: Wind Energy 2

3 Wind speed m/s World Renewable Energy Congress XI Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Figure 2 - Monthly average wind speed in Socotra during Figure 3 - Monthly variation of daily mean speed for Socotra using Homer software. Figure 4 - Daily mean wind speed for July Table 1- Assumption for electricity demand for a family in Socotra Island Appliance Time of Voltage Power Demand Energy demand operation V AC (Watts) Wh/day (Hours) 2 lights (fluorescent) 240 2x TV/Radio 240 1x Fan 242 1X Refrigerator 240 1x Total WE: Wind Energy 3

4 The main characteristic parameters of a wind generator are: the cut-in wind speed, V c, the rated power, P r, that is achieved at the rated wind-speed, V r, and the cut-off wind speed, V f. Table 2 shows the main specifications for the three selected wind turbine generators. Table 2- Characteristics data of the three wind generators Type 30 kw 80 kw 250 kw Length of blades (m) Hub height, (m) V c, m/s V r, (m/s) V f, (m/s) The average daily and annually energy production, for the three different wind generators is calculated. The capacity factors, the annual fixed and running cost was also calculated. The 30 kw generator indicates lower energy cost compared to the other two. Table 3: show the evaluation of the three different generators. Table 3- Evaluation of the cost of energy for three wind energy generators Type 30 kw 80 kw 250 kw Average daily power supply (kwh) Average annual generation (kwh) 156, , ,844 Capacity Factor, % Rate of fixed cost (US $)/year ,288 28,272 Operation cost (US $/year) ,023 Total present cost (US $) for life time = 20 year 202,217 48,450 1,157,385 No. of Households utilized Cost of energy (US $/kwh) In this analysis, the investment for electrical connections of the households are not included. Additional what mentions in assumption of demand/household, it is really required to supply invertors and batteries per consumer to gain continuous electrical supply. 3. Hybrid Options Analysis A hybrid energy system generally consists of a primary energy sources working in parallel with standby secondary energy storage units. HOMER software has been used to optimize the best energy efficient system for Socotra considering different wind PV combination and comparing with a stand alone system for a household using PV system. HOMER software is used to simulate the operation of the a system by making energy balance calculations for each of the 8,760 hours in a year. It performs these energy balance calculations for each system configuration and then determines whether a configuration is feasible and then estimates the cost of installing and operating of the system over the lifetime of the project. The system cost calculations account for costs such as capital, replacement, operation and maintenance. The solar radiation is approximately constant over the Island, the average monthly daily radiation is between 4 to 5 kwh/m 2 [5] Analysis shows that the cost of energy (kwh) is low for the system which is the combination of 180 homes. Table 4 shows financial summary of three systems. The cost of PV module including installation cost has been considered as US$ 5/ W. Life time of the modules has been taken as 25 years and these are tilted at latitude angle of the site. For these analysis a FORTIS turbine with a capacity of 30KW has been considered. The cost of the turbine with tower and installation has been considered as 202,217 US $. The project life time has been considered to be 25 years and the annual real interest rate has been taken as 4%. WE: Wind Energy 4

5 Table 4-Rate of capital cost and operation expenses for three systems Type Capacity System A: small community sized wind/diesel system Wind=30 kw Diesel = kw System B: small community sized wind/pv system Wind =3 0 kw =5 kw PV System C: household-sized PV system 200 W Average daily power supply (kwh) Average annual generation (kwh) 171, , Capacity Factor, % Rate of fixed cost (US $)/year Operation cost (US $/year) Total present cost (US $) for life time = 20 year 288, , Cost of energy (US $/kwh) Conclusion 1. Socotra Island has good potential in wind energy. So, it should take immediate practical steps to start implementation of pilot wind turbines projects. This is to examine the feasibility of introducing this technology in the Island and to improve the Island standard of living using pollution free means of proving electrical energy. 2. It could be summarized from the analysis that it will be better to use wind-pv combination system for numerous homes instead of single home system. The overall cost of energy would be low if the turbine cost decreases. Reference [1] A. Balfaqeeh (1990) Natural construction for Socotra island, Seminar on Geographical and Economical Importance for Aden, Aden, Dec [2] ESCWA, Proceeding of the seminar on small-scale solar and wind Technologies for Rural and Remote Areas, 29 Nov.-3 Dec E/ESCWA/86/WG.1/19 [3] HOMER, V 2.14, National Renewable Energy Laboratory (NREL), USA, [4] Meteorological data for Socotra Island, Meteorological Department, Aden, Yemen. Catalogue, Fortis, Windenergy, Netherland (2002). [5] S.M.Bin Gadhi, M.A.Mukbel, A.H.Algifri (1996) Potential of Renewable Energy in Socotra Island, Proceeding of 1 st International Scientific Symposium on Socotra Island, Aden, March WE: Wind Energy 5