Hassan Ibrahim

Study of Effect of Thermal Diffusivity on Ground Temperature for Malaysian Climate

Ground has been proven that it is able to supply cooling and heating resulting in significant reduction of electricity consumption. This paper discusses potential of ground towards implementation of ground thermal storage by using ground heat exchanger (GHE) to supply passive cooling for any application. Analysis has been conducted based on empirical equation from conduction heat transfer for depth up to 6 m and thermal diffusivity from 0.04 to 0.1 m2/day. The main input parameters were obtained from local weather station for three consecutive years. The results showed that significant reduction of temperature occur at depth below than 2.0 m in which cooling can be supplied constantly throughout the year. Temperature amplitude also gets attenuated relatively with depth in which amplitude less than 1°C occur at depth more than 4 m for thermal diffusivity 0.04 m2/day. In addition, thermal diffusivity plays important role in determining ground temperature variation. It has been obtained that the temperature amplitude significantly increase when the thermal diffusivity increase. Therefore, this paper had suggested that the application of GHE should be placed in condition of thermal diffusivity 0.06 m2/day and below.

Effect of Solar Fraction on the Economic and Environmental Performance of Solar Air-Conditioning by Adsorption Chiller in a Tropical Region

Solar air-conditioning (AC) is an attractive AC system but it has intermittent output, and therefore, a conventional heater is needed as a backup. This study presents the effect of ratio of heat delivered by solar (Qsolar) to the total heat delivered to an adsorption chiller (Qsolar + Qheater) or solar fraction (SF) on the economic and environmental performance of a solar AC. This solar AC is not a solar-assisted AC, and therefore, it needs to fully cover the cooling load. The cooling demand of an office building in Kuala Lumpur, and the performance of flat-plate collectors and the adsorption chiller were calculated by equest and watsun software and by a mathematical model, respectively. Economic performance was analyzed by life-cycle cost analysis, whereas the environmental performance was analyzed by using typical emissions rate of energy systems used. It was found that a boiler was a better solution than an electric heater as a backup heater. Furthermore, the net profit (NP) at lower SF was higher because of its lower capital investment, but more emissions were released compared to the conventional AC because of the boiler operation. Thus, when economic and environmental performance were fairly considered, it is appropriate to have solar AC with an SF around 0.74.

Simulation Model to Assess Electrical Power Generation from Tidal Basin in Coastal Area of Malaysia

This article studies the numerical simulation of power generation in four different tidal stations in the East Coast region of Malaysia. The tidal stations are Tanjung Sedili, Tanjung Gelang, Tioman and Cendering. The simulation model is based on power generation using tidal barrage. Ebb, flood and double-mode generations were studied. The tidal basin area was estimated by approximation to generate sufficient electricity for local community consumption. Thus, a different basin area was estimated for every location as each location has different population size. Single-flow generation was assumed for ebb and floor generations with 40% barrage efficiency while bi-directional generation was assumed for double-mode generation with 30% barrage efficiency. Double-mode generation has the highest power generation among the three different methods. Tanjung Gelang has the highest average tidal range difference. However, Pulau Tioman is more suitable to have the tidal barrage as the local community population is smaller, thus, requiring a smaller basin area to generate sufficient electricity to meet the demand of local community. On average, tidal barrage with a basin area of 0.3km2 in Pulau Tioman will be able to generate 13.74 GWh annually.

Study on the Application of Fit-Viability Framework for Renewable Energy Technology Evaluation

Malaysia has an abundance of renewable energy resources. However, the implementation proved to be difficult, as many factors have to be considered, mainly economical factor. Furthermore, currently there is no known framework to establish the feasibility study of renewable energy technology implementation. This paper serves as an initial study on the application of fit-viability framework for the implementation of RE technology, focussing in Malaysia. A simple case study has been performed based on the Feed-in Tariff mechanism, an the fit-viability framework proved to be useful in RE technology consideration.