Ali Sayigh

Stochastic simulation of hourly average wind speed sequences in Tangiers (Morocco)

Twelve years of hourly average wind speed data are used to build an autoregressive model (AR(2)) to simulate hourly average wind speed (HAWS). The model matches well the characteristics of the experimental values of the wind speed. Tests have been performed to validate the model. Comparisons have been made between generated and real series of data to check if the wind behaviour is reproductible. The model is then used to build up a reference year for Tangiers and may be used to forecast wind speed, with good results.

The Comparison of Three Types of Indonesian Solar Box Cookers

This paper describes the influences which govern solar box cookers: HS 7534, HS 7033 and the newest design HS 5521. The best of solar cooker, type HS 7033 gave oven temperature of 202°C between 12:00 and 12:45 p.m. on October 7, 1997. Thirty-four units of this type have been field tested since September 1997. It was found that these solar cookers have a good heat storage capability, therefore they can be used for consecutive cooking. The optimization of the size, the aperture area, the insulator thickness, the oven volume and the reflector area leads to a new design, type HS 5521. Its volume is only 35% of the volume of HS 7033 and cheaper. The performance comparison of the last two solar cookers are described based on the data collected during testing with and without load. The HS 5521 has the same heat collection rate and is able to cook as fast as HS 7033.

THE SOLAR OVEN: DEVELOPMENT AND FIELD-TESTING OF USER-MADE DESIGNS IN INDONESIA

This paper considers the design, use, and social acceptance of solar cookers that are constructed by their users. Several generations of oven design are described and their field testing in Indonesia, are reported, the first generation design having been described in a previous paper. The second generation design reached 175°C in oven temperature, and it used only local materials in its manufacture. Results of field testing of sixty four units in East Nusa Tenggara Provence, Timor Island, Sulamu village, and at Maumere City of the Sikka Regency in Flores Island, all in Indonesia, are reported. Social observations via questionnaires and direct conversation were conducted as part of the field study. Preliminary results showed promising tendencies of acceptance (up to 28%), and the solar ovens proved their ability to cook effectively. The most recent generation of design has reached 202°C in oven temperature, while costing 10% less than the previous one. The dissemination of thirty units of this design in two villages in West Nusa Tenggara Province is reported on.

The bioclimatic design approach to low-energy buildings in the Klang Valley, Malaysia

Formulating passive energy design strategies require an understanding of the climatic influence on buildings and the thermal comfort of their occupants. This paper presents the bioclimatic approach in building design as well as the techniques which are applied to formulate various strategies in order to achieve indoor comfort conditions. The paper deals with the Bioclimatic Chart, the Building Psychrometric Chart, Mahoney Tables and the Control Potential Zones which utilise the thermal neutrality concept. Regional climatic data from the Klang Valley area in Malaysia were utilised in formulating the design strategies. The most appropriate design strategies for hot, humid regions were then deduced. The most preferred strategies found were the use of ventilation, dehumidification and shading. Consequently, a full recommendation for the integral use of these three passive methods are suggested to be used in all buildings in Malaysia.

Cost of electricity generated and fuel saving of an optimized wind-diesel electricity supply for village in Tangier-area (Morocco)

In several of the remote areas of Morocco, diesel generators are used to provide electrical power. Such systems are often characterized by poor efficiency and high maintenance costs. The integration of wind turbine with a diesel/battery hybrid system is becoming cost-effective in windy locations.

Solar Oven, design, and its field testing in West Lombok regency, Indonesia

Design of four Solar Ovens, box type, are described. All materials used in the latest design are locally available. This is one of the basis of considerations in designing beside simplicity and long life time. Solar oven of the latest design yielded 160°C without load and 50 units have been field tested in West Lombok regency since July 1995. Its cooking ability, materials used, size and shape, social acceptance and further activities are described.

Thermal performance of different pond cells under actual climatic conditions in Qatar

Experimental work was undertaken to study the thermal performance of three different pond cells under actual climatic conditions of Qatar. The first cell was an open pond. In the second unit, a finned radiator, painted black, was placed over the pond. In the third cell, the water was contained in a polyethylene bag. Experimental results indicated that the exposed pond cell came out best, when considered in terms of how quickly the temperature of the stored water could be reduced, and how low that temperature could be. The water in the exposed pond was cooled directly (by evaporation and radiation to sky) whereas in the case of the finned radiator cell, heat had to be transferred from the stored water to the radiator, and then from the radiator to the surrounding. In the case of water-in-bag cell, evaporation was eliminated and radiative exchange with the sky was reduced due to the partial transparency of the polyethylene bag (in the infrared region).

Reducing Biomass and the Use of Kerosene for Cooking in Indonesia to Support the Global Efforts to Reduce CO2 Emission

We discuss Indonesia’s efforts in poverty alleviation within the context of national energy. The statistical data regarding provincial poverty lines, the number of people who live below this line, the energy type used by low-income families and the gender situation are given. Several approaches to energy provision for firewood consumers are described in the global context. It started with a field research initiative until the formation of a national program for socio-economic development including World Bank involvement. Various demands such as electricity development, overcoming climate change disasters and infrastructure reconstruction led to funding scarcity. We describe ideas/initiatives to obtain funding by showing the benefits of reducing CO2 emission. The estimated annual global costs of adapting to climate change and the Cancun Agreement are briefly described within the funding scarcity context.

Integrated visual and thermal analysis for tropical buildings

Publisher Summary This chapter discusses integrated visual and thermal analysis for tropical buildings. It presents the optimization of daylighting while maintaining energy efficiency measures for tropical buildings. The use of daylighting and daylighting technologies in buildings are becoming increasingly important. Energy can be saved from the use of natural lighting and since daylight has a higher efficacy and visual quality than standard lamps, natural lighting produces more lumens per watt of the total energy transmitted. However, simply by increasing glazing areas does not mean direct energy saved. Excess thermal gains may result from increasing aperture size. It can be shown that a 25% of window-to-floor ratio can produce desirable indoor illuminance levels during working hours throughout the year for the tropics. This value is somewhat higher than the recommended minimum window-to floor ratio in the building by laws of a tropical country. Finally, this chapter has shown that it is possible to determine the daylighting strategies required for energy efficiency in tropical buildings by utilizing simple integrated visual and thermal analysis tools.

Simulation to Design Indonesian Solar Cooker Type HS Using the Energy Profiles Information

Publisher Summary Simulation is essentially a numerical experiment that is done by altering certain design parameters to find out the possible improvement of a solar cooker box type and to predict the performance of a new design. The chapter describes a simulation to develop the design of Indonesian solar box cooker. The assumptions used and the physical considerations in designing are also discussed in the chapter. Simulations can generally produce information about effects of design-variable changes on system performance in relatively quick and inexpensive way. However, the physical experiment gives information that cannot be generated by this simulation such as a liquid droplet and a leakage at the glue because of the excessive heat. The numerical experiment indicates that the efficiency of the cooker can be further improved.