42 research outputs found
A Review of Hybrid Renewable Energy Systems Based on Wind and Solar Energy: Modeling, Design and Optimization
In this chapter, an attempt is made to thoroughly review previous research work conducted on wind energy systems that are hybridized with a PV system. The chapter explores the most technical issues on wind drive hybrid systems and proposes possible solutions that can arise as a result of process integration in off-grid and grid-connected modes. A general introduction to wind energy, including how wind energy can be harvested, as well as recent progress and development of wind energy are discussed. With the special attention given to the issues related to the wind and photovoltaic (Wind-PV) systems. Throughout the chapter emphasis was made on modeling, design, and optimization and sensitivity analysis issues, and control strategies used to minimize risk as well as energy wastage. The reported reviewed results in this chapter will be a valuable researchers and practicing engineers involved in the design and development of wind energy systems
Thermal Comfort Analysis on the Residential Buildings in Sarawak
Thermal comfort is a subjective response that reflects the contentment between one’s state of mind and the current environment. The energy consumption of the building sector has rapidly increased due to improved living standards and rising expectations of residents regarding thermal comfort. Mechanical ventilation, especially air conditioning systems, is essential for hot and humid countries aiming to achieve an ideal indoor comfort condition. However, such cooling systems often consume a significant amount of electricity, which contradicts the concept of energy conservation. Therefore, thermal comfort assessment is a method that can be employed to address this issue. Evaluating the thermal perception of occupants can subsequently facilitate more efficient electricity usage, aligning with the goal of energy conservation. In this study, a thermal comfort analysis was conducted on free-running residential buildings in Sarawak. These buildings were naturally ventilated with minimal use of mechanical ventilation systems. Physical measurements and subjective assessments were employed to evaluate the thermal responses of the residents based on various sensation and comfort scales, including the ASHRAE scale, Bedford scale, thermal acceptability scale, and thermal preference scale. Additionally, the widely used PMV model was utilized to predict the thermal sensation experienced by the residents. The results of the study indicated that the Bedford scale exhibited the highest percentage of acceptable responses, followed by the ASHRAE scale, thermal acceptability scale, and thermal preference scale. The PMV model was observed to overpredict the residents’ thermal responses. The comfort temperatures derived from the study were 27.5 ∘C, 28.1 ∘C, and 26.2 ∘C according to the ASHRAE scale, Bedford scale, and PMV model, respectively. Based on the actual percentage of dissatisfaction that ensures 80% satisfaction, the acceptable indoor temperature range was found to be 27.3 ∘C to 29.6 ∘C. Similarly, the acceptable range for relative humidity was 74.0% to 92.0%, and for air velocity, it was 0.18 m/s to 0.66 m/s.
Keywords: thermal comfort, thermal perception, sensation, comfort scale
Performance of Low Cost Alternative Radiant Cooling Panel in Malaysia
Radiant panel cooling is still considered uncommon in Malaysia due to unavailability of local manufacturers with limited architects or engineers who are familiar in the system. The initial construction cost for radiant cooling system may be higher than air system and not forgetting the need for a smaller supplementary air system to dehumidify the air to avoid condensation which is an inherited problem of the system in hot and humid region. Promotion and public awareness is lacking in the country and very much dependable on government demonstration program of green technology application where only a few governments owned building having such system. With the aim of long term energy and cost saving this study looks into the development of custom design and locally assembled low cost radiant cooling panel and how its performance in comparison to its overseas and more expensive counterpart could help in provide alternative cheaper building cooling system. Custom build cooling panels with selected materials were constructed and tested to find out its cooling capacity. Finite Element Method (FEM) software was used to establish a design chart to assist in the design and sizing of the alternative radiant panel for Malaysian residential house. The experiment shows that cooling performance in term of mean surface temperature and its cooling capacity is almost identical to its overseas counterpart. Use of cooling radiant panel with free night cooling of water as its chill water supply shows a significant energy saving potential while at the same time provide an acceptable room thermal comfort. Given the local made product having similar performance and suits local condition the technology could grow and be applied with confidence.    Â
Technology advancement in vehicle monitoring system for accident prevention
Significant development in urbanized cities causes vehicle ownership to grow with rapid rate. As a result, the saturation of vehicle in dense cities leads to insufficient transportation infrastructure, which causes an increase in road accident occurrences. The condition of vehicle and driver such as poor engine operation system, speeding, reckless driving, drowsy driving, drunken driving are the factors of accidents. Vehicle monitoring system is thus very important to be deployed as an effort for accident prevention to reduce the number of road accidents. This paper reviews the recent progress
and development of technologies in vehicle monitoring system for accident prevention. Various technologies in the system include Global Positioning System (GPS), Geographical Information System (GIS), Global System for Mobile (GSM), General Packet Radio Service (GPRS), image processing, Fuzzy Logic, data fusion and so forth. The issues and challenges in vehicle monitoring system are also presented in this paper
Implementation of a topographic artificial neural network wind speed prediction model for assessing onshore wind power potential in Sibu, Sarawak
This study presents a topographic machine learning based wind speed prediction model. Predicted and ground station data were used to examine the wind energy potential in Sibu. A terrain-based artificial neural network was developed using MATLAB/Simulink (2016). It was found that the developed model can predict wind speed values in areas where the model was implemented. The detailed wind resource assessment shows that the power and energy densities fall within Class 1, which is suitable for smallscale applications. The annual energy output of the selected wind turbines was found to be 2343.12–
12036.85 kWh/year with an annual capacity factor in the range of 2.16%–7.77%
Wind Speed Prediction in Non-Monitored Areas Based on Topographic Radial Basis Neural Network (T-RBNN)
A review on recent available positioning technologies and its advancement
This paper reviews and compares the available positioning technology for location based application such as the Intelligent Transport System (ITS) and personal vehicle positioning. With the rapid growing trend of worldwide vehicle ownership, issues such as traffic congestion, environmental pollution, energy consumption and road accident cases are increasing. Intelligent Transportation System (ITS) which depends on location and positioning has been identified as one of the advocated key to resolve the issues. Global Positioning System (GPS) is one of the most promising ubiquitous positioning technologies accepted worldwide for ITS application. It is discerned that GPS alone in ITS application is not adequate since GPS faced Non-Line-of-Sight (NLOS) and multipath effect. New technology integrated is needed to overcome the drawback of the current system for continuous positioning; particularly important for ITS application to be fully functional. This is the significant motivation for tremendous research works had been carried out to improve the performance of positioning. In this paper, advantages and disadvantages of the recent available positioning technologies being used in the implementation of ITS such as satellite-based positioning, network-based positioning and location integration of several positioning technologies is found to be able to improve accuracy, reliability, availability and applicability of the ITS
Investigation of earth tube system application in low income building in Kuching, Sarawak
Modern residential building in Malaysia particularly in Sarawak rarely consider the ground as a source of heat sink to cool down the building. This is probably due to the lack of information on surveyed ground temperature and energy modelling of such building. A typical low income residential building in Sarawak with earth tube was modelled in Energy Plus to determine the effect of earth tube to passively cool the building in Sarawak. From the simulation result, the indoor air temperature of the east facing zone of the building could be lowered from 33°C to 29.5°C. A further drop of about 0.6°C could be achieved if the room volume served by the earth tube is reduced. The PMV of the building were greatly reduced from 3 to 1.5 on a thermal sensation scale. The operative temperature is within 80% acceptability limits of 30.3°C operative temperature as per ASHRAE Standard 55 for naturally conditioned spaces. © School of Engineering, Taylor’s University
Measurements and Analysis of Mobile Satellite Signal Performance Using Handheld GPS Receiver
There is need for experimental data in the less
developed and developing countries such as Africa, Asia and Latin America for the study and analysis of mobile satellite signal performance for communication purposes. The experiments were carried out in open space area with no obstruction of the direct wave. Comparisons were made between the soft reformatted data obtained in Kano, Kota Samarahan in Sarawak and Fukuoka in Japan.
Data acquisition system developments were designed to
manage the open space environment satellite propagation data for the less develop regions, whereby adaptive graphical user interface (AGUI) was designed and developed to records the propagations data. Therefore the recorded data will be used to evaluate the signal performance in term of SNR, azimuth angles
and satellite elevation angles. Results obtained from analysis will be used to determine the characteristics of the open space environment. This method can be used to encourage more experimental works in the less develop countries. The analysis produced an important part in the studies of the signal performance.
The hyper-terminal intercepts and adaptive graphic user
interface were used to evaluate the previous data acquisition system conducted in Fukuoka and Stuttgart. The analysis for ionospheric effect on Mobile Satellite (MS) was conducted by comparing data obtained in Kota Samarahan, Kano with the data obtained in Fukuoka Japan. The experimental work was conducted with reduced cost and simple equipments so as to encourage more experimental studies on MS signal performance. Future research studies can be done by designing a program that will link and monitor the pilot data acquisition system placed in
remote areas. Rain sensor and satellite display view can be added to the AGUI
Night Cooled Radiant Cooling Panel for Sustainable Building Cooling Mode in Malaysia
Night air temperature in Malaysia is generally about 23°C and is a potential source
of heat sink to dissipate heat gain from a building. A thermal storage tank was used to store
a certain quantity of water and was passively cooled during the night using the pitched roof
as a heat exchanger to chill the water to as low as 22°C. The free cooling of water was then
used as a cooling medium to cool the modular radiant cooling panel during the day time
when the outdoor temperature exceeds 30°C. The experiment shows that the system was
able to maintain an indoor temperature of less than 28°C when the outdoor temperature
peaked to nearly 34°C while providing acceptable thermal comfort with certain controlled air
movement. The use of the hydronic radiant cooling panel with free night cooled water as its
coolant is proven to have signifcant energy saving potential of up to 85% while at the same
time provide an acceptable room thermal comfort which meets the international standard
criteria such as the American Society of Heating, Refrigerating and Air-Conditioning Engineers
(ASHRAE) Standard 55