1 PV-Diesel Hybrid Solution for off grid rural Areas of Bangladesh Paroma Jahan, Nusrat Chowdhury, Md. Fayyaz Khan Dept. of EEE, United International University, Dhaka, Bangladesh paroma.jahan@yahoo.com, nusrat_105@yahoo.com, fyk@eee.uiu.ac.bd Abstract—Electricity generation in Bangladesh mainly depends on its natural gas reserve. The reserve is depleting at a very fast rate and if no new reserves are discovered, then the present reserve would last for 7~10 years. An alarming situation would then exist and Bangladesh has to depend on the imported coal to meet its energy requirement. Majority of the people in the rural areas till to date do not have access to electricity. The grid electricity mainly meets the demand of urban and the industrial areas. In Bangladesh almost 80% of the total population lives in rural areas [1]. A large part of rural areas is not connected to the grid because of the high cost of transmission and distribution lines. So there are many off-grid areas which have no electricity supply. In that case the rural people mainly use kerosene based lamps for illuminating their homes at night and other domestic purposes. The cost of kerosene is quite high and the price is soaring up day by day. Besides, light output from these oil based lamps are extremely low and may give rise to health problems like eye defects, respiratory disorder etc. Bangladesh has a fairly good solar insolation.The average solar insolation is 4.2 KWh/m 2 - day[2] which is quite suitable for PV based power generation. Presently solar home system is getting popular in Bangladesh and around 30,000 units of solar home system are being installed every month in the off grid areas of Bangladesh [3]. Although the price of PV is going down but the use of storage device like battery makes the overall cost of the SHS quite high. Also, presently the per unit energy cost from the SHS is in the range of $0.50~0.60 which is extremely high. However, a hybrid system with PV and Diesel may bring down the energy cost to less than 50% of that of energy cost of SHS. In this paper, a dc grid PV system with a small Diesel generator as standby unit has been proposed to meet the energy requirement of the poor rural masses of Bangladesh. The same model can be applied to other off grid areas of developing countries of the world. A hybrid system has been designed with the help of popular software HOMER developed by NREL, USA. The main purpose of this paper is to determine the optimum size of the hybrid system that will fulfill the load criteria of household with the lowest electricity unit cost. A cluster of 100 households has been considered for the grid system. Each household load consists of 3 CFL (Compact fluorescence lamp) and 1 DC fan. The required power for every CFL lamp is 10Watts and 30Watts for DC fan, requiring an approximate load of 60w per household. Optimum cost of energy (COE) has been determined through the simulation software and the optimum size of PV, battery and diesel have been also been determined by HOMER. Keywords- SHS, COE, HOMER, GRID AND OFF GRID AREAS I. INTRODUCTION Bangladesh is suffering from severe generation problem due to insufficient reserve of natural gas. At present, the PDB (Power Developing Board) is producing around 3900 to 4100 MW electricity against the demand of around 5200 MW[4]. In our country per capita electricity generation in 2000–01 and 2005– 06 were 129 kWh and 170 kWh, respectively [1]. Only 31.2% of the total population is connected to grid electricity (about 80% of urban and 23% of rural households), where the vast majority being deprived of a power supply [1]. Although the government of Bangladesh has declared to provide electricity for all by the year 2020, seems to be quite impossible to achieve. Besides, the electricity demand is increasing at a rate of 8% per year.[1].The increased demand of electricity is presently managed by regular load shedding in the grid areas of Bangladesh. There is hardly any area which is not affected by severe load shedding especially during the summer time. So at present no further area is possible to bring under national grid at least for coming years till new sources of hydrocarbons are found. Renewable energy sources especially PV based systems may be the pragmatic solutions for generation of electricity in the off grid areas of Bangladesh. In this paper we developed a hybrid system with a combination of diesel and PV. A study by the German Advisory Council on Global Change (WBGU) in 2003 predicted a growing potential for solar energy as an important energy carrier for the future. The achievable picture was that solar energy cover nearly 30% of global energy demand by 2050, and nearly 70% by 2100 [5]. However Considering the climate of Bangladesh solar energy is the appropriate form in renewable energies. Daily solar radiation varies between 4 and 6.5 kWh/m 2 [1]. Therefore this paper aim’s to show that the cost of energy can be reduced by using Hybrid PV- Diesel system. II. CASE STYDIES OF HYBRID PV-DIESEL SYSTEM In this paper, two case studies have been made for hybrid PV- Diesel system. In the first case, we divided the 100 household into three clusters. Each cluster consist 30 houses, 30 houses and 40 houses respectively. The cost of energy for each cluster has been studied. In the second case, we considered a mini off grid system for overall 100 households. The cost of energy for mini off grid system (100 households) has been studied. An optimization tool known as Hybrid Optimization Model for Electric Renewable (HOMER) has been used for all the simulation & analysis of the data. The HOMER software