Direct use of solar heat is a simple cooking option, though somewhat inconvenient.
I'd like to see a solar oven based on a thermal transfer medium which heats a cooking void indirectly --- steam or other working fluid.
Advantages would be that the cooking itself would be more conventional, within an oven (possibly resembling a thermal-mass wood-burning stove, and ideally, usable with fuel for instances in which sunlight was insufficient). Several cooking / heating chambers and/or surfaces could be arranged for different heating needs.
And because of the thermal mass, the at least over the course of the day, cooking and baking would be reasonably insensitive to at least short-term interruptions of clouds or other weather.
You might have to get used to cold breakfasts however.
I find few references for anything resembling this design, far more common are solar "box cookers", typically achieving temperatures of ~150-160 C (~300-325 F).
To my knowledge, it's not common. The Auroville Solar Kitchen is pretty much precisely what I had in mind, and it's the first I've heard of such a thing. I'd really like to see more specifics on what they're doing, though it looks as if there are a mix of ovens and steam tables offered.
The use of a fixed-position spherical mirror (rather than parabolic) solves the problem of a moving aim point ... a spherical mirror always has the same region of focus, even if it "smears" that focus a bit. Since what's beeing gathered is heat rather than image information, that loss of precision makes for a more robust structure (particularly given high winds, as noted).
Other options would be flat absorptive panels (sufficient for pre-heating a working fluid to much-less-than-boiling temperatures) or a parabolic or hemispheric trough type reflector which focuses on a pipe or channel running the length of the mirrors.
I'd like to see some more technical information (a quick DDG search does turn up some promising results), and it seems there are some more extensive documents and specs.
> She says that they once did a blind test with some customers. They cooked the same cut of beef in a gas oven and in the satellites. “Everyone preferred the second version,” she says. The layer of walnuts, restaurant cooks explain, add smoky notes to the food while also filtering the sun’s rays to aid in even cooking.
So they're altering the recipe / dish layout slightly to accommodate for the different heating style, which alters the flavor.
It is more steamed than baked. All of the moisture is intact which leads to a lot juicier piece of meat. I recommend the GoSun portable unit that is ~$100 to explore cooking with the sun.
Also it looks like they are searing the outside in a way by using the clear dishes over an opaque material that is directly absorbing the infrared heat.
radiation... of... sunlight? They're satellite dishes, covered in mirrors, making them solar ovens just like the ones you can buy at any random camping store. Just better, because they're (a lot) bigger.
I've been to the Machanents House, it's run by a wonderful family. It was at night so I doubt they were using the solar powered stove, the food was great regardless. Excellent hospitality, the two eldest daughters sang beautiful folk songs while Grigor (mentioned in the article) was cracking jokes and making toasts all night long. He kept giving me shit for not making eye contact while shouting "kenatz!" (cheers). Highly recommended experience.
Yerevan is such a cool city, were you visiting family or on vacation? I took a solo trip there a few years ago and keep hoping to return and see a little more of the countryside.
Apparently borosilicate is only good up to ~500°C, and only for very short periods of time at that. But per my other comment there are other variations such as aluminosilicate which can withstand much hotter temperatures.
This piqued my curiosity and I did a bit of research. Apparently there are a variety of glasses that can withstand that kind of heat such as aluminosilicate glass and fused quartz / high silica glass.
There are also commercial formulations such as Robax, which is apparently some kind of transparent ceramic good up to 825°C (although the temperature / time load capacity listed for that temperature is only 5 hours. Assuming the solar ovens reach a maximum of 700°C you get a far more reasonable 5000 hours).
I haven't seen anything about cookware rated to those kinds of temperatures, so I'd assume it's custom-made out of something like the above.
22 comments
[ 4.2 ms ] story [ 57.7 ms ] threadI'd like to see a solar oven based on a thermal transfer medium which heats a cooking void indirectly --- steam or other working fluid.
Advantages would be that the cooking itself would be more conventional, within an oven (possibly resembling a thermal-mass wood-burning stove, and ideally, usable with fuel for instances in which sunlight was insufficient). Several cooking / heating chambers and/or surfaces could be arranged for different heating needs.
And because of the thermal mass, the at least over the course of the day, cooking and baking would be reasonably insensitive to at least short-term interruptions of clouds or other weather.
You might have to get used to cold breakfasts however.
I find few references for anything resembling this design, far more common are solar "box cookers", typically achieving temperatures of ~150-160 C (~300-325 F).
This somewhat resembles the concept: https://www.webplaces.org/solaroven/design.htm
Isn't this kind of common?
See this for example: https://solarcooking.fandom.com/wiki/Auroville_Solar_Kitchen
To my knowledge, it's not common. The Auroville Solar Kitchen is pretty much precisely what I had in mind, and it's the first I've heard of such a thing. I'd really like to see more specifics on what they're doing, though it looks as if there are a mix of ovens and steam tables offered.
The use of a fixed-position spherical mirror (rather than parabolic) solves the problem of a moving aim point ... a spherical mirror always has the same region of focus, even if it "smears" that focus a bit. Since what's beeing gathered is heat rather than image information, that loss of precision makes for a more robust structure (particularly given high winds, as noted).
Other options would be flat absorptive panels (sufficient for pre-heating a working fluid to much-less-than-boiling temperatures) or a parabolic or hemispheric trough type reflector which focuses on a pipe or channel running the length of the mirrors.
I'd like to see some more technical information (a quick DDG search does turn up some promising results), and it seems there are some more extensive documents and specs.
I dont understand why it would taste better than inside an oven other than temperature difference.
> She says that they once did a blind test with some customers. They cooked the same cut of beef in a gas oven and in the satellites. “Everyone preferred the second version,” she says. The layer of walnuts, restaurant cooks explain, add smoky notes to the food while also filtering the sun’s rays to aid in even cooking.
So they're altering the recipe / dish layout slightly to accommodate for the different heating style, which alters the flavor.
Also it looks like they are searing the outside in a way by using the clear dishes over an opaque material that is directly absorbing the infrared heat.
https://cockeyed.com/incredible/solardish/dish01.shtml https://makezine.com/2007/06/06/the-light-sharpener-12-fo/
That’s nearly 1300 F... I wonder what kind of glass cookware they’re using that can withstand those kind of temperature shifts without exploding?
There are also commercial formulations such as Robax, which is apparently some kind of transparent ceramic good up to 825°C (although the temperature / time load capacity listed for that temperature is only 5 hours. Assuming the solar ovens reach a maximum of 700°C you get a far more reasonable 5000 hours).
I haven't seen anything about cookware rated to those kinds of temperatures, so I'd assume it's custom-made out of something like the above.