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Life cycle assessment (LCA) is considered to be the most systematic methodology that is widely used in the area of energy analysis. However, embodied energy (EE) and carbon (EC) analysis requires significant time and effort to ensure the reliability of the LCA results. Therefore, a more comprehensive model of conducting the energy analysis is required to provide more realistic EE and EC analysis in turn. Hybrid LCA has been identified as the best model in improving the completeness of EE and EC inventory data. However, such a benefit was not empirically verified extensively, especially in the Malaysian construction industry. This paper demonstrates an extended application of hybrid LCA to Malaysian building design systems, and further investigates the completeness of the model. Finally, the potential for EE and EC reduction through the allocation of low EE and EC intensities of alternative materials, products or components has been evaluated. The results revealed that the hybrid LCA improved the completeness of the EE and EC inventory data compared with other models. By using low EE and EC intensity materials, products or components, a total EE and EC reduction of 43% and 41%, respectively was achieved. The results showed that the proposed methodology can assist designers practically during the early stage of the design process in the Malaysian construction industry. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents an optimization for hybrid PV/wind system based on loss of load probability (LLP) and system cost. This paper is divided into three main parts: optimization of PV array, wind turbine and battery, optimum PV array tilt angle and optimization of the inverter size. Firstly, the optimization performed is aimed to select the optimal capacities of the PV array and wind turbine that give minimum system cost. However, the optimization was done using a hybrid iterative/genetic algorithm. The iterative part of the proposed algorithm is applied to generate a set of possible configurations for the proposed system, while the genetic algorithm is applied to find the optimum configuration. Secondly, a model for optimizing the tilt angle of the PV array is presented based on the Liu and Jordan model. Finally, an iterative method for optimizing the inverter size in the proposed system is presented. The results showed that the optimum sizes of the PV array (C A ), wind turbine (C s ) and storage battery (C B ) are 1.1411, 0.7159, and 0.550, respectively, while the optimum inverter''s size (Rs) is 1.37. Lastly, by applying the calculated monthly optimum tilt angle, the collected yield of the PV array is increased by 7.96%. [Copyright &y& Elsevier]

This paper presents two grid-connected photovoltaic (PV) systems (monocrystalline silicon, c-Si; copper–indium–diselenide; CIS) situated on the rooftop of the solar lab building in the National University of Malaysia, southwestern Malaysia. Various parameters were used to analyze the system performance; including array yield, final yield, capacity factor, and performance ratio. The recordings were noted down under the actual climatic conditions for an entire year. The variables of energy cost and payback period were also considered to calculate the economic feasibility of the system. Variations in the final yield of CIS were as low as 2.98 h/day in July to the highest value of 4.31 h/day in March. The final yield for c-Si power plant ranged from 2.92 h/day in July to 4.14 h/day in March. The calculated capacity factors for CIS and c-Si power plants were 15.6% and 14.4%, respectively, in July as the worst value, and 21.12% and 20.2%, respectively, in March as the best value. In the case of CIS power plant, the performance ratio ranges from 63.8 in July to 84.12 in March, and for c-Si power plant, it ranges from 59.92 in July to 79.14 in March. The energy cost and the payback period of the suggested system were evaluated as 0.045 USD/kWh and 28.44 years, respectively. Finally, this study provides valuable information for those who are interested in PV system installation in the tropical zones. [ABSTRACT FROM AUTHOR]

• Performance evaluation of GCPV system from monitoring of two years PV productions. • Calculation of PV derating factor from actual PV system output. • Error between simulation and actual performance is reduced using derating factor. • Performance of GCPV system increases 4.8% using optimal tilt angle and orientation. This paper presents the real performance of a 7.8 kWp grid-connected rooftop photovoltaic (PV) system from a field monitoring at a residential house under the feed-in-tariff scheme. The performance parameters of PV system were assessed based on the two-year energy production in 2018–2019. PVsyst software was used to find the best orientation and tilt angle for the selected area to increase the system performance. Next, the PV derating factor was calculated from the two-day data collection. The derating factor was used in the simulation of the system using HOMER Pro, and the economic parameters for 21 years project lifetime were predicted. The results show that the performance of the installed system was better for 2019 compared to 2018 due to the higher solar irradiance in 2019 and the malfunction of inverter in July to August 2018. The best performance ratio obtained from the recorded data was 75.72% and the average loss was 1.68 kWh/kWp/day. The annual capacity factor and overall system efficiency were in the range of 13%–16% and 10%–12%, respectively. The best tilt angle and orientation was 5° with the increment of annual energy production up to 4.8%. From the simulation, the error between the simulation and measurement results was high when the derating factor was assumed to be 100%. When the value used was based on the calculation obtained from data collection, the annual error was 1.7%, which is acceptable. Thus, the software is considered reliable assuming no component failure in the PV system. From the economic analysis, the annual net profit can be obtained was almost RM 3,000, and the payback period was in the range of 5–7 years. In addition, the installed PV system on the single house has the potential to reduce the CO 2 emission of approximately 7.45 tons/year. [ABSTRACT FROM AUTHOR]

Abstract: In this research, an optimisation for building integrated hybrid PV/diesel generator system for zero load rejection for Malaysia is performed. The optimisation is performed considering a loss-of-load probability (LLP) less than 0.01. However, the daily averages of solar energy for Malaysia and a mathematical model of a hybrid PV/diesel generator system are used in this optimisation. The optimisation presented in this paper aims to calculate the optimum capacities of a PV array and diesel generator, which investigate the minimum system cost. An optimisation problem in terms of system units’ cost is solved graphically in this study. Moreover, the optimised system is compared to other energy source choices to highlight its feasibility. The recommended configuration of a PV/diesel system located in Malaysia is CA =1.2, CDG =0.3, while the optimum CB is 0.1. The results of the optimisation show that a PV/diesel generator choice is more feasible compared to a standalone PV system or diesel generator system because it reduces the system cost by 35%. [Copyright &y& Elsevier]

Abstract: This paper presents an assessment of occupants’ opinion of the internal environment of buildings, based upon their responses to questions relating to a range of discrete factors. The survey considers many aspects of the internal environment and seeks to gain occupants responses to each of these in terms of “User Satisfaction” and “Degree of Importance”. The questionnaire utilised a seven-point bi-polar scale to score these responses against each of the factors. In addition, the questionnaire elicits a ‘fingerprint’ that combines up to 22 factors relating to satisfaction with the building. The study documents and considers aspects of the building environment for which the users noted that they were least satisfied as well as those that are considered by the occupants as being of most importance. It is critical that sustainable development results not just in resource conservation, but also in increasing productivity and occupant well-being within buildings. This study hopes to provide insight for the design community on the perceptions of occupants in relation to building performance based on indoor environmental quality (IEQ) criteria. It also seeks to add to the growing body of research on sustainable design and occupants’ perception of IEQ. [ABSTRACT FROM AUTHOR]

Abstract: This study investigates the effectiveness of night ventilation technique for residential buildings in hot-humid climate of Malaysia. This paper firstly presents the results of a survey on usage patterns of windows and air-conditioners in typical Malaysian residential areas. Secondly, the effects of different natural ventilation strategies on indoor thermal environment for Malaysian terraced houses are evaluated based on the results of a full-scale field experiment. The results show that the majority of occupants tend to apply not night ventilation but daytime ventilation in Malaysian residential areas. It can be seen from the field experiment that night ventilation would provide better thermal comfort for occupants in Malaysian terraced houses compared with the other ventilation strategies in terms of operative temperature. However, when the evaporative heat loss of occupants is taken into account by using SET*, the night ventilation would not be the superior technique to the others in providing daytime thermal comfort mainly due to the high humidity conditions. Therefore, the indoor humidity control during the daytime such as by dehumidification would be needed when the night ventilation technique is applied to Malaysian terraced houses. Otherwise, full-day ventilation would be a better option compared with night ventilation. [Copyright &y& Elsevier]

Abstract: The popularization of 24h pay-TV, interactive video games, web-TV, VCD and DVD in Malaysia are poised to have a large impact on overall TV electricity consumption in the country. With the increasing of overall TV energy consumption, energy efficiency standards are one of highly effective policies for decreasing electricity consumption in the residential sector. Energy efficiency standards are also capable of reducing consumer''s electricity bill and contribute towards positive environmental impacts. This paper attempts to predict the amount of energy that can be saved in the residential sector by implementing minimum energy efficiency standard for television sets in Malaysia. Over the past 30 years, television ownership in Malaysian residents has increased from 186,036units in 1970 to 2,741,640units in 1991. This figure is expected to reach 6,201,316 units in the year 2010. Hence, efficiency improvement for this appliance will have a significant impact on the future of electricity consumption in this country. [Copyright &y& Elsevier]