A.K.M. Sadrul Islam

Techno-economic feasibility of grid connected solar PV system in Bangladesh

A techno-economic feasibility analysis is done for 500 kW grid connected solar photovoltaic (PV) system at a northern location of Bangladesh. HOMER and RETScreen computer tools and monthly average solar radiation data from NASA is used for this study. The unit electricity production cost is found to be 14.51 BDT (Bangladeshi Taka) based on project lifetime 20 years and 10% discount rate. It is also found that the unit cost varies between 15.25 BDT and 14.10 BDT, using the monthly highest and lowest solar radiation at different locations in Bangladesh. Considering the selling price of electricity 10 BDT/kWh with 5% electricity escalation rate annually to the grid, the IRR, equity payback and benefit-cost ratio are found to be around 5.6%, 13.1 years and 0.68 respectively without considering any clean energy facilities. The total annual greenhouse gas reduction is estimated to be 658 tons.

MIXED CONVECTION AND ENTROPY GENERATION CHARACTERISTICS INSIDE A POROUS CAVITY WITH VISCOUS DISSIPATION EFFECT

This paper examines and explains two-dimensional, steady mixed convection flow in a porous square vented cavity. The interaction between the buoyancy stemming from one or more heated elements inside a microstructure filled vented enclosure and an imposed forced flow forms the topic of this investigation. Analysis has been carried out for two different boundary conditions. Initial investigations are carried out for walls of the enclosure being isothermal. A second stage of analysis is performed keeping only the left wall isothermal and other three walls adiabatic. Natural convection takes place due to temperature difference between the isothermal wall and the fluid. Forced convection condition is imposed by providing an inlet and a square vent inside the enclosure filled with fluid saturated porous medium. The mathematical model is developed using modified Darcy flow model and energy equation. Through the adaptation of the well known finite element method, solution to this numerical problem is obtained. Governing parameters chosen are Peclet Number (Pe), Rayleigh Number (Ra), Aspect ratio (AR) and the width of the inlet as a fraction of the width (I/W) of the enclosure. For detailed analysis different value of these parameters such as five Rayleigh Numbers (1, 50, 100, 500 and 1000) and seven different Peclet Numbers (0.1, 1, 5, 10, 20, 50 and 100) are considered. Effect of inlet to cavity width ratio is examined within the range 0.1 ≤ I/W ≤ 0.5 for a particular aspect ratio. The performance of the enclosure in both cases; are determined by flow visualization and by analyzing different parameters such as Bejan Number, Nusselt Number and Entropy Generation Number. Isotherms, streamlines show substantial variation in their pattern or magnitude. Average Nusselt number and average Bejan Number increases whereas Average energy flux density decreases with increasing I/W. These fluctuations also vary for different Rayleigh or Peclet numbers. The results for both the boundary conditions are also compared to find the most effective value of I/W.Copyright

Green Electricity from Rice Husk: A Model for Bangladesh

Bangladesh has reportedly over one hundred thousand Rice Mills large, medium and small. They process paddy, using mostly the parboiling practice. The rice mills use the thermal energy of steam generated in boilers, which are fired by rice husk a byproduct of paddy processing in the rice mills and which is globally well-known as very convenient source of dry biomass energy of reasonable heat value. In global context, annual rice husk production is 137 million tonnes whereas, in Bangladesh, about 9.0 million tonnes of rice husk is produced reported in 2011 [1]. In Bangladesh context, out of 37.08 million tonnes of total biomass produced from agro-residues, rice husk contributes about 26% by mass [2]. At present about 67-70% of rice husk is consumed for steam producing in rice mills [3, 4]. With a few exceptions, presently most of the ‘boilers’, used in these rice mills of Bangladesh are very inefficient. This results in a huge wastage of rice husk, which is an important source of biomass. Preliminary estimates are indicative that at least 50% of the rice husk produced could be saved and made surplus for its better use as input for small power generation [5]. Energy demand for rice processing is increasing every year due to the increased production of rice for ensuring food security of the population. More energy efficient rice parboiling boilers is to be suggested to replace the existing inefficient rice parboiling systems. So that the surplus amount of rice husks could be available for other sectors. If this husk is to be briquetted, then it will be an alternative fuel for replacing wood-fuel. Rice husk based co-generation system could be an alternative for large rice mills, or even for a cluster of small to medium rice mills. If the electricity were generated from rice husk then net carbon dioxide emissions could be reduced [6]. As a matter of basic dissemination strategy, applicable to most of the developing countries, initially the entrepre‐ neurs/investors feel shy to invest in a relatively new area technology, as they lack the confi‐ dence on the technical functioning and financial/economic viability of ventures in such an area. Before launching a husk based power generation technology, it is important to know the

Environmental impact of rice husk briquette fuel use in Bangladesh: A case study of Mymensingh

The rice husk briquette fuel option is found to be the most environment friendly in the study area compared to wood fuel, natural gas and kerosene. The annual saving of CO2 is found to be 16.42×103 tonne by using 100% briquette fuel instead of 100% wood fuel (non-sustainable source) in the study area that would be US

Optimized model of a solar PV-biogas-diesel hybrid energy system for Adorsho Char Island, Bangladesh

197.04 ×103 worth annually. The cost of CO2 reduction is found to be −0.77 US

Application of Nanofluid in Heat Exchangers for Energy Savings

/ton that reveals, no additional cost is incurred due to the replacement of wood fuel stove by briquette fuel stove system. The sensitivity analysis expressed that the economic viability affected by the performance of rice husk briquette fuel over wood fuel (i.e. wood : briquette ratio) and the price variation. It is found that the rice husk briquette fuel option is viable up to wood: briquette ratio of 1.12 and variation in price of briquette up to 48%, if the additional cost incurred is reimbursed by the return from CO2 at a trade value of US

Utilization of Nanofluid in Various Clean Energy and Energy Efficiency Applications

12.00/ton of CO2.

Heat transfer enhancement and pumping power optimization using CuO-water nanofluid through rectangular corrugated pipe

Adorsho Char is an island situated in the bank of Feni River, Bangladesh with a current population of 860. This island is underdeveloped and lacks the electricity supply from the main grid. Majority of the population make use of conventional means i.e candles, lanterns, kerosene wick lamps for lighting the households whereas some market area use solar PV at a very small scale. The aim of this paper is to present an optimized model of a solar PV-biogas-diesel hybrid energy system to provide electricity for the people living in the island. A field survey has been conducted to collect the information about the population, load demand, number of cattle and the current condition present in the island. Hybrid Optimization Model for Electric Renewable (HOMER) has been used to optimize the energy system modelled for daily peak demand of 35 kW (181 kWh/day). Batteries have been considered to facilitate electricity storage. The optimization result from HOMER consisting all energy resources reveals an optimized system architecture of 7.2 kW solar PV, 16 kW biogas generator, 9 kW Diesel generator and 12 batteries (1,900 Ah each) in terms of cost of electricity (COE). This system configuration provides electricity at 17.37 Taka/kWh (

Economic and environmental assessments of solar home systems consisting different lighting sources

0.217/kWh) with a net present cost of 8,573,095 Taka (

A techno-economic assessment for charging easy bikes using solar energy in Bangladesh

107,163.69).