Note: The yellow line in this graph illustrates how the “ideal” curve would look like is this would have been a rather cloudless day with full sunshine. The curve used as a baseline for the other days is based on the data collected on December 23, the day with the most boiled water cycles during the testing period.
The World Meteorological Organization defines sunshine as direct irradiance from the Sun. “solar irradiance” measures the amount of solar energy that arrives at a specific area at a specific time. A pyranometer, the SDL-1 Solar Data Logger was used to determine how much solar power could be produced from the available sunlight (solar insolation) at the test site every day. With the SDL-1 data is logged as solar irradiance in watts per square meter and cumulative incident solar energy in kilowatt hours per square meter. In plain English: When it is cloudy the curve drops and when the sun comes out the curve goes way up.
SOLAR COOKER TESTING: DECEMBER 28, 2008
Setting: Boiling batches of water of 1 US gallon (3.78 liters) as many times as possible in all four solar cookers. Temperature was measured at 30-minute intervals and at boiling point for each unit.
Goal: To establish how many heating cycles, reaching 212˚F/100˚C can be achieved in one day by each unit. After the boiling point had been reached the water was immediately discarded and replaced with a fresh batch of ambient temperature.
Set-up: CooKit aluminum pot with glass lid. SK14 closed black pot with solid lid. BlazingTubeSolarAppliance: enamel pot with lid. Time frame: Testing (data collection): 10:00h to 22:30h
Charts: Y-axis: The charts below show the water temperature in degrees Fahrenheit (boiling point for water is 212˚F/100˚C) for each cooker tested.
X-axis: Indicated the time it took to boil each 1 US gallon (3.78l) of water. The curve drops down to 80˚F if the water was replaced with ambient temperature water.
TABLE: Data from all 5 days testing days. Water heating cycles of 1 us-gallon (3.78l) reaching the boiling point of 212˚F/100˚C as many times per day as possible
Dec 22 '08
Dec 23 '08
Dec 24 '08
Dec 27 '08
Dec 28 '08
RESULTS: Due to the weather, with occasional rain showers, solar insolation was significantly lower on December 28.
With the exception of the BlazingTubeSolarAppliance none of the units reached the boiling for one gallon of water during the entire day. The CooKit could not be tested under these weather conditions.
The BlazingTubeSolarAppliance reached the boiling for one gallon of water once during the day. After reaching the boiling point in the second batch of one gallon of water in the late afternoon, it remained in the BlazingTubeSolarAppliance for and extended test duration until 22:30. The water temperature inside the insulated sealed cook box was still 153˚F/68˚C at 22:30h.
Results in the graph below exhibit superior conservation characteristics of the BlazingTubeSolarAppliance for many hours after sunset.
Note: If you are interested in a full report of the testing procedures and results as a pdf file please write to us at:Info
In case you check and send your email on-line, e.g from yahoo or gmail, please copy the email address and paste it into your "to:" filed. Our email address is: info(at)blazingtubesolar.com
The pdf file of the research results is rather large (4MB). It contains all nine days testing data in detail.