What is it?

More soon . . . 

Update on 2014-03-24 23:54 by Jonathan Hanson

Since Craig recognized the mystery product as a Sunrocket, a solar kettle/thermos, here's the rest of the story.

The Sunrocket is manufactured by Sun Cooking, an Australian company that also makes a solar oven. Lest you dismiss solar ovens as a street-fair curiosity suitable for roasting hot dogs one at a time, know that Roseann uses a solar oven (from a U.S. company) to produce probably 25 percent of the meals at our off-the-grid home in the desert, summer and winter. Those meals have included roast chicken, stews, biscuits, even cakes and cookies, all produced with zero fossil fuel and zero carbon emissions. So I was intrigued by the idea of a solar kettle, the counterpart to my venerable volcano kettle that boils water in a couple of minutes using a twig fire oxygenated by a vortex effect.

The Sunrocket (made in China) comprises a central tube of doubled, evacuated glass with a high silicon content for thermal stability and strength, side reflectors of polished aluminum, and a plastic body, with a metal handle that doubles as a lock for the reflectors and a prop to orient the tube toward the sun. A vent in the screw-in lid releases steam when the contents boil and acts as a safety valve. The capacity is listed at a half liter (17 ounces); however, the instructions say to leave a bit of air space at the top, leaving actual capacity at a bit under a pint. This would be enough for two cups of tea, or one large cup of coffee using a pour-through filter. (Curiously, while the website calls it a Sunrocket, as does the box it comes in, the embossing on the actual product says SunKettle, which I like better anyway and plan to use as the generic reference.)

I filled this one and set it in the sun on a balmy (70ºF) afternoon. An hour later the water inside was at 160ºF. Okay, so it's no volcano kettle—however, that temperature and dwell time would have been enough to safely purify water from a suspect source. And of course I was free to ignore the kettle and start writing this piece. The center tube was cool to the touch—fascinating how easily heat can get in and yet not out. Thirty minutes later the water was at a near-boiling 200º—plenty hot enough for coffee or tea. And given the vacuum insulation, the contents will stay hot for hours.

The sun kettle, deployed.

Conclusion? While it's not exactly compact (the box, in which I'd be sure to carry it for protection, is 4.5 by 18 inches), or fast, the effortless and completely green nature of the Sunrocket makes it a nifty device for camping. I'll continue to use my volcano kettle for morning coffee (which I want right now), but the Sunrocket will have water hot for elevensies. And it would be excellent for leaving in the sun to heat water for washing—or purifying—while you do other things.

Sun Cooking is HERE. The Sunrocket ($67 including shipping) is available in the U.S. HERE.