Be Veg, Go Green, Save the Planet!

How to enjoy solar cooking --- Grilling sweet potatoes

Solar panel cooker is not a efficient cooker. There are better alternatives available. However, its cost is low enough by low income communities around the globe. In the following experiment, we will demonstrate that food stuff can be grilled in a solar panel cooker without a metallic pot.

Method

Step 1: Get hold of the required materials. All you need are:

A steal or bamboo steamer.

A sweet potato.

A sheet of aluminium foil with one side painted in black.

A microwavable box or a high temperature plastic bag.

A solar cooker .

 

Figure 1. The required materials other than solar oven (Photo taken at 10:30, 11 Feb 2009)

Step 2. Wrap the sweet potato in blackened aluminium foil. To minimize contamination, it is important not to let the black side of the aluminium foil to touch the sweet potato. The black side of the aluminium foil is designed to absorb infrared radiations and, as such, it should face outwards.

To play safe, the sweet potato can be wrapped in clean foil in the first place, and then wrapped in blackened aluminium foil.

 

Figure 2. Sweet potato to be wrapped in blackened aluminium foil, with the black side faces outwards. (Photo taken at around 10:30, 11 Feb 2009)

Step 3. Place the wrapped sweet potato from step 2 into the microwave box (or high temperature plastic bag). Use the steam steamer to support the sweet potato. The microwave box (or high temperature plastic bag) acts as a greenhouse enclosure.

Figure 3. Sweet potato supported by the steamer and enclosed inside the microwave box. (Photo taken at around 10:30, 11 Feb 2009)

Step 4. Start solar grilling at around 11:00.

 

Figure 4. Solar grilling at around 11:00. (Photo taken at around 10:30, 11 Feb 2009. At that time, the starting temperature was about 23 deg C. )

Step 5. Wait until afternoon. Enjoy your meal.

Figure 5a. In two hours, the greenhouse enclosure was filled water vapor, suggesting that sweet potatoes may reach a temperature above 100 deg C.

Figure 5b. Sweet potato fully grilled. (Photo taken at around 14:30, 11 Feb 2009. At that time, the temperature was about 79 deg C. )

Concluding remarks

While this experiment shows how we can enjoy solar cooking without a metal pot, the implication of this experiment is stunning. We have demonstrated the fact that localized heating has been easily achieved as a result of the combined effects of the greenhouse enclosure and the blackbody radiators.

The icy ground in the north pole of this planet is largely reflective. As a reflective layer that reflects the solar radiations to outerspace, the icy ground blocks the solar radiations from penetrating into the ocean bed, thus keeping the toxic gases frozen underneath the ocean. However, the ground and water underneath the ice layer are mostly non-reflective and they can become new blackbody radiators which absorb more sun heat if the ice layer covering them are not there. As of right now, however, the concentration of the greenhouse gases is on the rise to an unprecedented level, whilst the icy areas in the northern hemisphere are shrinking.

Have you ever imaged what will happen in the coming future if the ice cap in the north pole of this planet continues to melt, exposing the non-reflective ground? The ocean bed in the north pole is full of toxic gases. According to a report , the methane gas in Arctic is beginning to bubble to the surface from the ocean bed, thanks to the sun heat that penetrates into the ocean bed. Methane is not the only harmful gas underneath the ocean that is to be released into the atmosphere. If this cycle continues unchecked, a runaway greenhouse effect occurs and the excessive build-up of methane in our atmosphere will sooner or later cause mass extinction. This event is not unprecedented in historical record.