volume-01-Issue 1 (2010)
Renewable Energies: A Sustainable Future or a Prosperous Business
IJTEE, volume-01, Issue 1 (2010) , PP 51 - 55
Published: 22 Jan 2010
by Ammar Moussi, Greg Asher from University of Biskra, Biskra, Algeria, 07000, University of Nottingham, Nottingham, UK, NG7-2RD
Abstract: Recent global developments appear to guarantee a market for green renewable energy. Among several sources of renewable energy currently explored, photovoltaic systems appear to be promising in view of their environmentally clean nature and the advantage of direct conversion to electrical power. In spite its high initial cost, solar energy production is rising steadily. Today's investment in the sector of renewable energy shows that a promising industry is being inaugurated. This paper discusses through the outcome of statistical and technical facts the paradoxical issues between environment sustainability and business development. read more... read less...
Keywords: Renewable energy, Sustainability, Investment
Wind Data Collection and Analyses at Masdar City for Wind Turbine Assessment
IJTEE, volume-01, Issue 1 (2010) , PP 43 - 50
Published: 22 Jan 2010
by Isam Janajreh, Ilham Talab from Masdar Institute of Science and Technology, Abu Dhabi, P.O. Box 54224, United Arab Emirates
Abstract: Wind turbine technology has improved dramatically in the last two decades and their deployment and implementation increased by 20-25% annually. Wind is neither chaotically generated nor is based on random phenomenon. Wind is predictable to greater extend. Current predictive models lack the validation against collected historical data. In this work a 50m meteorological tower was installed at Masdar City for continuous collection of annual wind data records. Data is sampled at 10 minutes sampling rate using Campbell 1000 data logger connected to cup vane anemometry at 5 different heights to estimate the boundary layer profile. Collected and estimated wind energy density was below 120Watt/m2 suggesting low wind area and undermining the feasibility of wind turbine implementation in the city. Data is analysed for their first (mean and standard deviation) and second moments (correlation and spectrum) and found to vary considerably in scale and time suggesting simultaneous time and scale analysis. Wavelet analysis is used to study the intermittency of the wind data and quantify their intermittency factor read more... read less...
Keywords: Wind Energy, Wavelet Analysis, Frequency Spectrum
Solar Photocatalytic Degradation of Environmental Pollutants Using ZnO Prepared by Sol-Gel: 2, 4-Dichlorophenol as Case Study
IJTEE, volume-01, Issue 1 (2010) , PP 37 - 42
Published: 22 Jan 2010
by Muneer M. Ba-Abbad, Abdul Amir H. Kadhum, Abu Bakar Mohamad, Mohd S. Takriff, Kamaruzzaman Sopian from Department of chemical and process engineering, Faculty of Engineering and Built Environment Universiti Kebangsaan Malaysia, Selangor, Malaysia, Solar Energy Research Institute (SERI),Universiti Kebangsaan Malaysia, Selangor, Malaysia
Abstract: The photocatalytic degradation of 2, 4-dichlorophenol (2,4DCP) in aqueous solution was carried out in batch process with ZnO prepared by sol-gel method. The effects of various factors, such as different calcinations temperatures and amount of catalyst were investigated for efficient degradation of 2, 4-dichlorophenol. The UV/Vis Spectrophotometer was used for analysing the concentration of 2, 4-dichlorophenol in solution at different time intervals during the experiment. The photocatalytic degradation of 2, 4-dichlorophenol was investigated by monitoring molecular absorbance at λ = 285 nm. The average solar intensity of ultra violet (UV) was recorded as 23 W/m2. The photocatalytic activity of the ZnO was evaluated by photocatalytic degradation of initial concentration 50 mg/l of 2, 4-dichlorophenol. Optimum value of catalyst dose was found to be 2 g/l. The experimental results showed that the photocatalytic degradation efficiency of 2, 4-dichlorophenol for 1 h irradiation time was up to 98 %. read more... read less...
Keywords: Solar photocatalytic , Sol-gel 2, 4-dichlorophenol
Energy Use, Energy Savings and Environmental Analysis of Industrial Boilers and Compressors
IJTEE, volume-01, Issue 1 (2010) , PP 29 - 36
Published: 22 Jan 2010
by R. Saidur, M. Hasanuzzaman, N.A. Rahimb from Department of Mechanical Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia, Department of Electrical Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia, Centre of Research UMPEDAC, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia
Abstract: In this paper energy use, energy and bill savings, emission reduction and pay period using highly efficient motor, variable speed drive by modulating speed of boiler and compressor has been estimated using energy audit data. It has been found that 68,923 MWh, 132,922 MWh, 78,769 MWh and 49,230 MWh of energy can be saved for 40%, 60%, 80% and 100% motor loadings, respectively for 20% speed reduction in the boiler system. Corresponding bill savings for the aforementioned energy savings have been found to be US$ 4,411,052, US$ 8,507,028, US$ 5,041,202, and US$ 43,150,751 for 40%, 60%, 80% and 100% motor loadings, respectively for 20% speed reduction in the boiler system. Energy savings and bill savings resulting from the use of high-efficiency motor in air compressor are 6703 MWh, 8251 MWh, and 10571 MWh, total energy, can be saved for 50%, 75%, and 100%, motor loadings, respectively. Similarly, bill savings for the preceding amounts of energy savings are US$ 428,984, US$ 528,042 and US$ 676,538, respectively. It is also clear that the use of high efficiency motor and VSDs leads to substantial energy savings and an enormous reduction in emissions. read more... read less...
Keywords: Energy, Energy savings, Environment, Boiler, Compressor.
Performance and Operational Experiences of Solar Driven Cooling Plant after Five Years in Operation
IJTEE, volume-01, Issue 1 (2010) , PP 23 - 28
Published: 22 Jan 2010
by Ahmed Hamza H. Ali from Department of Energy Resources and Environmental Engineering, Egypt-Japan University of Science and Technology (E-JUST), P.O. Box 179, New Borg El-Arab City, Alexandria 21934, Egypt
Abstract: The main aim of this study is to report the performance evaluation as well as the gained operational experiences of a solar-driven cooling plant after 5 years in operation, in addition, based on the gained experiences, a suggestion for an appropriate small-scale solar-driven cooling plant for hot arid areas is presented. The plant includes a 35.17 KW cooling (10-RT) absorption chiller, vacuum tubes collectors with gross and net areas of 108 m2 and 72 m 2, a hot water storage capacity of 6.8 m 3, a cold-water storage capacity of 1.5 m3 and a 134-kW cooling tower. The plant provides air-conditioning for a floor space of 270 m 2. The plant performance results indicate: instead, small solar energy values at the plant location, the daily solar fraction ranged from 0.33 to 0.41, and for the duration from August 2002 to November 2007 the total solar energy supplied to the chiller is 53914 kWh and the total external energy (gas energy) supplied to the chiller is 35249 kWh and their percentage are about 60% and 40%, respectively. The collectors’ filed instantaneous mean efficiency value is about 0.63, the monthly average value varies from 34.1 % up to 41.8 %, with a five-year average value of 28.3 %, respectively and the daily chiller COP varies from 0.37 to 0.81, respectively. The gained from the operational experiences are: in hot arid areas, the water normally is rare, thus the re-cooling system should be designed based on dry re-cooling techniques. Moreover, based on the total initial capital cost of the entire solar cooling system, adsorption-cooling technology for small-scale solar-driven air-conditioning systems is the most appropriate. This is because these chillers can be driven by a low temperature energy source that can be obtained from flat plate collectors where, costs are a bit lower for flat plate collectors with liquid heat transfer carrier read more... read less...
Keywords: Solar cooling, Absorption chillers Lithium bromide-water operational experiences
Economic and Environmental Modeling of a Photovoltaic-Wind-Grid Hybrid Power System in Hot Arid Australia
IJTEE, volume-01, Issue 1 (2010) , PP 15 - 22
Published: 22 Jan 2010
by G. Liu, M. G. Rasul, M. T. O. Amanullah, M. M. K. Khan from Power Engineering Research Group, Faculty of Sciences, Engineering and Health, CQ University, Queensland 4702, Australia
Abstract: Increased concern about energy crisis and environmental issues has revitalized interest in the application of renewable energy technologies. For ensuring steady and continuous electricity generations, a hybrid power system (HPS) including more than one renewable energy elements is introduced. In this paper, environmental and economic analyses are used to discuss the sustainability of a HPS. An investigation is made on small-scale operations of 100kWh per day HPS as a grid-assisted power generation consisting of solar (photovoltaic) and wind energy. A comparison is drawn among the different configurations of a grid-connected HPS operation focusing on environmental and economic impacts. Emissions and the renewable energy generation fraction (RF) of total energy consumption are calculated as the main environmental indicator. Costs including net present cost (NPC) and cost of energy (COE) are calculated for economic evaluation. To simulate long-term continuous implementation of the HPS, the hourly mean global solar radiation and wind speed data of 2007, from Alice Spring (23.70S, 133.88E) of Australia, are used as an example of a typical hot arid climate. The monthly solar exposure between 13.31 and 21.3 2 MJ m day and mean wind speed of 7.13 / in 2007 is considered for simulation The Micropower Optimization Model software HOMER developed by the National Renewable Energy Laboratory, USA is used for simulation. It is found that, for Alice Spring arid climates, the optimum results of HPS show a 64.3% reduction of emissions including CO2, 2 SO, and NO x. Renewable fraction of the optimized system is 54%. It is also found that the HPS has benefits of cost saving. The reduced NPC and COE are only equal to about 85.3% of energy consumption from standard grid. In addition, through a set of sensitivity analysis, it is found that the wind speed has more effects on the environmental and economic performance of a HPS under the specific climate. read more... read less...
Keywords: Environment; Economy; Hot Arid Australia; Hybrid Power System.
Effect of Façade Type on the Cooling Load of a Multi-Storey Building
IJTEE, volume-01, Issue 1 (2010) , PP 9 - 14
Published: 07 Sep 2010
by Rafat Al-Waked from College of Engineering, Prince Mohammad Bin Fahd University (PMU), Al Khobar, Kingdom of Saudi Arabia, 31952
Abstract: The thermal and energy implications of a number of façade configurations on the lowest potential energy consumption for a multi-storey building have been investigated using the IES Virtual Environment software package. A preliminary 3-Dimensional computer model of the building was created and a number of different analyses were undertaken to ascertain the optimum façade configuration from an occupant comfort and thermal energy consumption perspective. Results have demonstrated that any one façade or glazing type will not provide the best solution in terms of peak loads, overall energy consumption, occupant comfort and cost. Any solution must therefore be a compromise between these competing factors. On the basis of these results, it has been found that a higher performance glazing results in the lowest peak cooling load, however, a more moderate performance glazing results in the best overall energy consumption. read more... read less...
Keywords: Passive Cooling, Thermal Analysis, Energy Performance, Window Glazing
Solar Energy to Drive Half-Effect Absorption Cooling System
IJTEE, volume-01, Issue 1 (2010) , PP 1 - 8
Published: 22 Jan 2010
by Rabah GOMRI from Laboratory of Génie Climatique, Engineering Faculty, Department of Génie Climatique 25000, Constantine, Algeria
Abstract: This paper presents the simulation results and an overview of the performance of low capacity two stage half-effect absorption cooling system (10kW), suitable for residential and small building applications. The primary heat source is solar energy supplied from flat plate collectors. The complete system (solar collectors-absorption cooling system) was simulated using a developed software program. The energy and exergy analysis are carried out for each component of the system. All exergy destructed that exist in this solar cooling system is calculated. Critical temperatures which are the minimum allowable hot water inlet temperatures are determined. This system has shown promising characteristics. When the condenser temperature is fixed at 28°C, 32°C and 36°C it can be concluded that between time of day 10 and 14 solar collector provides about 96%, 95% and 91% heating energy required respectively with a cover of about 100% between time of day 11 and 13 which correspond to a maximum of solar radiation. The daily cover is about 71%, 70% and 65% respectively. read more... read less...
Keywords: Absorption cooling system Performance; Solar energy Two stage Half-effect system.