Heat retention cooking with a Rand Solar Vacuum Tube and a Silicon heating pad

So more testing with the silicon heater pad, used my vacuum tube solar oven heat reached well over 300 deg, was able to cook bread in 45 min after it reached temp which was I am guessing 2 hours. Still pulling 200 watts of power, today is cloudy but my panels still put out 300 watts + so this is a big win!

Super cool!
I like the plywood cradle too.
I think I might try this with a stainless steel vacuum flask I have.
Come to think of it, there is at least one 4 -5 quart vacuum insulated retained heat cooker that includes a warming coil and runs on AC or DC.
It's made by Tacoma.
I was looking for devices that would let me cook while traveling when he found it on Home Depot's website.

Obviously you dig solar cooking, what got you going on using photovoltaic instead of thermal solar?
I can imagine it might be the ability to capture the energy and send it indoors, or maybe PV is less in need of tracking, better able to exploit diffuse light,ect.

You could build a open source version of the gosun.
I like what you are building.
Looking forward to more updates.

Yep that is my plan I like sharing what steps I have been taking.     After doing testing with this I need a different heating element, the silicon is off gassing inside the solar tube. the silicon heater works better connected to aluminum as with my testing with the thermo cooker..     I have been considering other options like a soldering iron, or a fish heater, or a light bulb.

>>[quote=William Bronson]Super cool!
>>I like the plywood cradle too.

Thank you I took some ideas I found on the net and made it on my CNC.    

>>I think I might try this with a stainless steel vacuum flask I have.
>>Come to think of it, there is at least one 4 -5 quart vacuum insulated retained heat cooker that includes a warming coil and runs on AC or DC.
>>It's made by Tacoma.

I did a quick search I could not find the cooker you mention.     I guess my next purchase will be a Cavey which cans as well as cooks food.     I believe I could cook my meal and at the same time can 3 other jars of food that I can just put on the shelf for later.      That is my way of dealing with leftovers :-)



>>I was looking for devices that would let me cook while traveling when he found it on Home Depot's website.

Another good place to look is truck stops, they have traveling cooking items.

Also some people cook on the manifold of the car as they drive.


>> Obviously you dig solar cooking, what got you going on using photovoltaic instead of thermal solar?
>> I can imagine it might be the ability to capture the energy and send it indoors, or maybe PV is less in need of tracking, better able to exploit diffuse light,ect.[/quote]

I have about 3000 watts of solar, so on a cloudy day that goes down to 300 - 400 watts.     I want to be able to learn what can I do with that much energy, and  what is the most efficient  / less time / less money spent way to prepare food.

I have considered tracking, but if you setup two sets of panels, one for morning, one for evening then you have energy the whole day and you don't have to worry with the motor for the tracker.      I like less things to break.

Note,  I am moving away from this as the silicon heats up too much in the vacuum tube and is starting to break down and put out fumes.     I suggest a different heating element for this venture, I don't have problems in the thermal cooker.

You don't have to use a heating mat. All you need is a 200C silicone wire (400F).
You will have to figure out the right gauge+length to get the right resistance to match your voltage+current.
Even better would be a temperature dependent bimetal switch that open at 350F. Example
It's a good idea to move away from that heating mat, looking forward to your improved design.

S Bengi wrote:You don't have to use a heating mat. All you need is a 200C silicone wire (400F).
You will have to figure out the right gauge+length to get the right resistance to match your voltage+current.
Even better would be a temperature dependent bimetal switch that open at 350F. Example
It's a good idea to move away from that heating mat, looking forward to your improved design.

Interesting, is this what you are talking about?

https://www.ebay.com/itm/24-AWG-Silicone-Ultra-Flexible-200-C-Heat-Resistant-Wire-1-10-25ft-Lot/323389503580?hash=item4b4b84385c:m:m6mX0ETI_A5JUfEtt4rzPwQ:rk:6:pf:0

The pad I am using now is this ->
https://www.ebay.com/itm/183309592866?ul_noapp=true

Yes that is the wire that I am talking about.

My original use case for it is for radiant floor heating powered by solar panels, with the floor being the thermal battery.
And in the summer the unused solar panel can be used to run AC/tools/etc. And even in low sun conditions, the power would go to the "Lead-Acid" battery 1st and if there is excess it would then go to in floor radiant heating.