Living Car Free - Portable Solar Cooker?

Last weekend I was cooking out with my solar cooker and wondered if anyone uses a portable solar cooker for picnics. Mine folds like a large suitcase so is bikeable but bulky. I've never biked it down to the river or anything like that. I use it as an alternative to a gas grill out on the deck. So, is there a portable model that works well for car-free people? I see portable camping models around on the internet but would like to read good or bad reviews from people who bike with them.

I haven't used it, but this (http://solarcooking.org/spc.htm) one looks simple, light, and cheap.

Same site, but I like the look and simplicity of this one.
http://solarcooking.org/windshield-cooker.htm

And for those in hammocks - you probably already have one of these. (they're one of the tips for hammocks - reflective and insulative without the bulk needed for sleeping on the ground and covering bumps) And as always a good thing for touring - using something for more than one use. Sleep on your stove...

I haven't gotten around to trying it out yet (I found it in winter).

Can these solar cookers really heat up food as fast as a gas stove (in full sunlight)?

As far as I understand (I've never used one), they're more like a slow cooker. Put it out in the sun in the morning, it will be ready by dinnertime. I suppose it would depend on how large it is, what you're cooking in it, and how intense the sunlight is.

Can these solar cookers really heat up food as fast as a gas stove (in full sunlight)?
The one I use isn't so portable, thats why I was asking if anyone has used a very portable (bikeable) that also works well. Mine is large non-carryon suitcase size when folded. It isn't so much full sun but how much haze or water vapor is in the air that affects how well it works. One of the NOAA sites has water vapour images and when those images show low vapour the cooker works as well as a gas stove even if it is partly cloudy. I've used it when the air temp is in the mid twenties but the sky was deep blue color. In DC I've never seen it raise the inside temperature above 370 F or so but down in Florida I've seen the same model slightly above 400 F.

I was hoping some of the simple living crew had experience with a very portable cooker I could more easily take on picnics.

How about this one? I've never used one myself but I might try this out sometime.

Solar Cooker (http://www.safetycentral.com/solarcooker.html)


Made from a patented and flexible material, it folds into a 14"x 14"x 2" packet.

http://us.st11.yimg.com/us.st.yimg.com/I/safetycentral_1898_42272966

Yeah! Cooked lunch (hot dogs, rice) and dinner (pasta) with the sun today.

The CooKit, like the one pictured in DavidLee's post is of the slow-cooker variety. You can get one for something like $25 from solar cookers international. Its pretty portable, but you'll need the 3 qt pan and you'll need to let it set around for 6 hours or more typically. Mostly I use mine for tapioca, though it would probably do chicken and other meats OK this time of the year.

For a *fast* solar cooker (by solar cooking standards), there is the Solar Sizzler (http://www.solarsizzler.com/). I consider this the best parabolic cooker value in North America, and maybe the only truly portable unit available anywhere. It snaps apart to refit into its shipping box. The box can fit in my grocery panniers. You will also need a tripod grill and a tripod stand to hold the parabolic. I was able to do a solar-park trip one time with my daughter, grill, stand, and cooker using our burley trailer. Otherwise, I think its about 2 backpacks worth of cooking stuff including pans and utensils.

An intermediate solution is the Parvati cooker, a design from India that can be made with ordinary household materials. The original design is available from

http://www.angelfire.com/80s/shobhapardeshi/New_developments.html

On good days, this has boiled water in as little as 50 minutes though 90 minutes is more typical. In 60 minutes you can have cooked rice. In 90 minutes you can have a nice cooked potato or split pea soup (better if you cook it longer) -- a family favorite. Cooked hotdogs today in one (6 at once) -- incredible how plump they got. I've also used this to bake bread in a can at the park. My version uses cooking jars for the cooking pot, wire mesh to hold the jar, and a couple pieces of wood as a backboard. By making this with velcro, you can have a version that will fit completely in a daypack sized bag. In the attachment, you see a small child holding the entire unit.

BTW -- what cooker are you using?

Why is this thread in the Car Free forum?
Did you used to make pot pies on your engine block?

Marks:
OK, I've seen on the internet all the cookers people have mentioned except the solar sizzler. Here is a photo of my clunky one in action. It works well but only the reflectors fold up. One reason it works well is the box is insulated so it retains heat. I'm concerned about the loss of performance with the foldable ones that don't use and insulated box. The solar sizzler looks like splattering grease would fall on the reflector and hurt performance.

Powers2b: Didn't I say I was looking for a portable bikeable cooker that a car free person had experience using? That is why it is on car-free. I'm not interested in hearing from a car driver about lugging one around in a car since I don't have a car.
That is why it is on a car free forum.

Marks:
OK, I've seen on the internet all the cookers people have mentioned except the solar sizzler. Here is a photo of my clunky one in action. It works well but only the reflectors fold up. One reason it works well is the box is insulated so it retains heat. I'm concerned about the loss of performance with the foldable ones that don't use and insulated box. The solar sizzler looks like splattering grease would fall on the reflector and hurt performance.
Ah, you have the Sun Solar Oven -- beautiful. Might be portable with an extracycle.

Hmm. There was a smaller solar box oven similar to the Sun Oven but made of cardboard. Smaller, so more portable when folded down. But probably not as powerful.

Insulation is certainly a good thing, but its not as important as you might think. The reason for this is that the R value of the glass is so low that heat escapes no matter how well the rest of the box is insulated. Its like trying to store water in a funnel. No matter how well the sides of the funnel are designed, the water is going to slip out. Also, what's important is how hot the food gets, not how hot the air in the box happens to be in the upper corner.

As I see it, the primary purpose of glazing and insulation is to prevent *convection* loss due to wind and ambient air currents. Trapping in heated air is not as important since its not the hot air doing most of the heating.

The Parvati and others use a cooking bag sheet around the jar or across the top trap in heat, which turns out to be pretty effective as indicated by the cooking times I provided. Its probably the most portable semi-powerful solution you'll find.

Use cooking vessels with clear glass covers when cooking with the Sizzler. This will prevent most grease splattering. I'd guess that small amounts of dust and grease only have about 5-10 % effect on performance. Disassemble the Sizzler to handwash from time to time with mild soap and water. At home, keep inside to prevent dirt from building up. Assemble and disassemble on a blanket or other soft surface to prevent scratching. The Sizzler is the one that will be most impressive at picnic events.

Oh, there's a new cooker that's getting good reviews:

http://www.realgoods.com/shop/shop6.cfm/dp/602/ts/5010478

Hard to tell, but looks like the 5 qt cooking oven/pan could fit in a messenger bag or panniers. The reflector for it folds down.

Good luck!

I like realgoods a lot but boy are they expensive!