Today, Solar Cooker SIAPv5.3.1 was tested by boiling 4 chicken eggs. Starting at 10:30 am, SIAPv5.3.1 was put in place, on top of a rack with the 4 reflectors opened into position. The eggs were placed inside the blacken pot on top of a thin tissue paper cushion, which in turn was placed inside the cooker chamber of SIAPv5.3.1. It was determined to boil the eggs without water!
The whether was bright and clear, a perfect whether for solar cooking. Though there was a couple of minute when the cloud has overcastted, it did not affect the overall cooking process. The highest temperature registered by the two thermometer, one was spirit-tube type while the other was barometric type, was consistent ie 125 deg C.
By about 1:00pm, the cooker was opened and the eggs were inspected. It was found that the 4 chicken eggs were well cooked. The eggs were opened and later consumed. Pictures were taken for record and future reference.
Saturday, April 5, 2008
SIAPv5.3.1 Experiment on 5 April 2008
Thursday, April 3, 2008
Ir. Liew, Than Ho Allen
PEng, MIEM, MEng, BSc.
Kuching, Sarawak 93250, Malaysia
Email: solarists@gmail.com
Abstract
Solar cooking is a method of cooking using the energy from the sun directly. It works by collecting the energy from the sun in the form of light, divert it to the spot of interest and trap it to heat the food. There are many advantages in solar cooking; amongst them are low upfront investment, not running cost, little maintenance and best of all, environmentally friendly.
Solar cooking is widely practiced in many places around the globe, both the developed and underdeveloped countries. In developed countries, they are used mainly due to environmental consciousness; while in the under developed countries they are used due to the acute needs against the scarcity of cooking fuel. In interior Sarawak, where the transportation cost of fuel is high, solar cooking can be one or the only solution.
The results of my experiments carried out in Kuching recently proof that solar cooking is not only possible, indeed very encouraging. In sunny days, my solar cooker could cook food almost just as fast as conventional gas or electrical stoves. Further, due to the nature of radiated heat in a solar cooker, food cooked in a solar cooker taste better and much nutrient can be retained. In addition, cooking food in a solar cooker can be unattended, as it will not burn.
It is my hope that the relevant ministries, departments and organizations could support and emphasize researches into solar cooking in the State. Further researches are required to ensure best adoption and adaptation of solar cookers for the State, so that it could benefits the people as well as play our part in conserving the earth.
Sunday, February 17, 2008
Weather of Kuching
Is our weather in Kuching suitable for Solar Cooking ?Lets look at some data posted by the following organizations:
- Malaysian Meteorological Service
- World Weather Information Services
Comparative studies amongst the three sites are ploted in a graphs as attached. These sites are:
- Pheonix
- Danan- Vietnam and
- Kuching- Malaysia
Monday, February 4, 2008
SIAPV3.0, is a parabolic solar cooker.
SIAPv3 is a reflector type of solar cooker. It consists of a parabolic reflector and a cross rack to hold the cooking pot. The parabolic reflector is constructed using a 24dBi/2.4GHz parabolic grid antenna, dressed with aluminium foil.
The paraboloid measures 1000mm(L)x 600mm(W), has a focus located around 370mm from the centre was used as the reflector frame. Above the frame, aluminium foil was laid to turn it into a solar reflector.
The cross rack is made from a mix of 25mm dia aluminium and pcv tubes. The cross leg and the top frames are made of aluminium, whereas the bottom frames are made of pvc tube. Aluminium tube could provide the necessary mechanical strength and heat resistance, while the pvc tube provides the basis mechanical strength.
The cross legs are held in position using two tension frames. The tension frames are made of aluminum rail that are fitted with pvc u-clips. On each tension frame, one u-clip is fixed at the end and three u-clip are fixed on the other end, starting from 300mm from the he first unit, at 50mm interval.
The Pot and Platform
A stainless steel port with lid was used. This pot is covered with aluminium foil before it is sprayed with flat black (Anchor No 29) paint, likewise for the cover.
Gauge 18, GI wire mesh with grid size of 50mmx50mm, measuring 300mmx300m was placed on top of the cross leg to turn it into a platform for holding the pot.
The Experiment
During the test today, the rack and the reflector were placed in position before half a liter of water was poured into the pot, which contains 4 chicken eggs.
The reflector was laid flat against the floor surface. The height of the reflector was adjusted to ensure the focus is on the pot.
Observation and Results
The water inside the pot starts to heat up when the sky is clear with ample sunlight. However, when the sun is shaded by cloud, the pot cool off rapidly.
The reflector made of aluminium foil was not smooth and did not make a good reflecting surface. The chicken eggs fails to completely cook at the end of the experiment. It was about 80-90 cooked.Conclusions and Recommendations
Lack of constant sun during the experiment causes the pot to repeat the heating and cooling process. The repeated heating and cooling of the pot is not conducive for the boiling of the chicken eggs inside. The highest temperature inside the pot measured 70C was not hot enough to boil the egg quickly.
The pot shall be insulated on the side and perhaps on the top to reduce heat loss. Mirror could be used in place of the aluminum foil as the reflecting surface to maximize the reflection. The focus of the reflector shall be established to ensure the pot is indeed sitting on the focus.
Report by Allen Liew 22/9/07 5:15 pm
Sunday, February 3, 2008
Testing of Solar Cookers
Yesterday, I have the privilege to meet my secondary school teacher, Mr. Yee, who is now retired. We have a fair bit of discussions on my work on solar cookers and he seemed impressed with the capability of Solar Cookers, and my work! I am sure he could contribute a lot in the development and promotion of Solar Cooking in Sarawak.
Perhaps after the Lunar New Year, I could send some of my Solar Cookers for him to evaluate. I need him to test, record and report the performance of my prototypes. Those data could help me to proceed, provide tips for me to improvements the designs. I am sure with the assistance from Mr. Yee and other individuals like him, we could do better in saving the earth.
Link to Solar Cooking International
A directory of the Solar Cookers promoters can be found in : http://solarcooking.org/directory.asp. It lists the solar cooker promoters country by country. You can check the link to my blog as in
http://solarcooking.wikia.com/wiki/Allen_Liew
