Tuesday April 22, 2008
Boil water with the sun
IT might just look like a glass tube but it provides boiled water, rendered safe by natural power from the sun. That is the solar kettle for you, an earth-friendly product invented by solar enthusiast Alex Kee.
“The solar kettle is the answer to providing safe drinking water to the global poor and needy, in a sustainable and renewable way, with compliments from the sun,” says Kee, an IT businessman who dabbles in solar energy out of pure interest.
The kettle is made up of two glass tubes, one encased in the other. You fill it up with water, leave it in the sun for an hour or two, and you get boiled water. Kee, 50, had in mind rural places with no piped water or electricity when he designed the solar kettle.
“Building fire involves time and work to collect firewood. With the solar kettle, you just leave it in the sun. It is suitable for places like Africa, where fuel is scarce and collecting firewood is causing deforestation. It is also a survival tool when you go to places with questionable water quality.”
The glass tubes are the standard ones used for solar thermal water heaters but no one had thought of using them to boil water until Johor Baru-based Kee came along.
“It is a simple idea but the novelty is in the design,” says Kee, who conceived the solar kettle in 2002.
Made from borosilicate (Pyrex) glass, the tubes are more than 70% efficient in converting solar energy into thermal energy. A vacuum between the two glass tubes, as well as two layers of coatings on the inner tube, ensures maximum heat absorption and minimal heat loss. This raises temperatures inside the tube to above boiling point.
The 0.75m-long tubes are manufactured in China according to Kee’s specifications, and each stores 1 litre, or four cups, of water. The tube also functions as a thermos flask, keeping boiled water warm until needed. When packed in its padded carry case together with a stopper and stand, it weighs 1.2kg, so it is portable.
As the temperature inside the tube can soar to 220°C, it can cook too. A scaled-up version of the kettle, with the tube diameter widened from 5cm to 10cm for easier food placement and retrieval, is what Kee calls the solar oven. He has boiled sweet potatoes and even baked pizzas in it. For pizza, he spreads a strip of dough on a metal sheet (for easier removal from the tube), adds the topping, pops it into the tube and it is done 30 minutes later.
“You can also cook rice but you have to watch it closely as the temperature can go up and burn the rice.”
He is not selling the solar oven yet since he needs funds to order the first 1,000 units. As for the solar kettle, Kee has sold less than 100 units so far, through direct sales and mail order, and mostly to foreigners. “They just like the idea, and some buy to donate to rural folks.”
Various corporations and charitable groups have made enquiries but none have made bulk orders for his invention, priced at RM200 each.
“The people who need it are too poor to afford it. So my vision is to get aid to donate the solar kettles to rural folks and the orang asli. If I can get a grant to order the tubes in bulk, the price can be halved.”
It is a pity that the solar kettle is not getting the attention it deserves. By tapping the boundless, renewable and free power of the sun, it is the kind of sustainable product the world should be making and using. – By Tan Cheng Li
For more on the solar kettle, go to solarcooking.wikia.com/wiki/Alex_Kee