Posted: 11/6/2025 5:13:08 PM EDT
[Last Edit: DaGoose][Edited]
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Couple of articles that may be of interest. The main site has a lot of stuff that may be of interest if you want to look at a low/no tech route for survival. How to Build a Solar Powered Electric Oven How to Assemble an Electric Heating Element from Scratch |
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I just skimmed it, it’s a neat idea-I think I understand that you are using a solar panel to heat the terracotta in the oven up so that you can cook even after the sun goes down. One fly in the ointment is that directly connecting the oven to a panel doesn’t get nearly the best power that the panel is capable of-really only about 2/3 of it. It’s not a huge deal as MPPT controllers are pretty inexpensive in the power ranges we are talking about, but you would need a battery of some kind to make it all work. (With an MPPT controller as they need a battery load) I can see something like this working fairly well, but it wouldn’t be the same as using a conventionally powered oven. No matter how hot you can get the oven, it is still a matter of mathematics in terms of how much energy in is needed to fully cook X amount of food mass. Such an oven might do a great job on a low mass item like a Hot Pocket, but an apple pie? Sure, 100 watts will get an insulated terracotta box pretty damned hot, but putting a chicken in it will cool that terracotta right off and then you are back to trying to cook a chicken with 100 watts when normal toaster ovens need 15-1800 watts. Most of you guys have seen my thread on my solar ovens, a lot of the same physics apply only they cut out the middle man of the solar panel and the direct connection efficiency issue-my solar ovens don’t work after dark though-well, two of them do because they have 12V heating elements for that.. Not saying it’s a bad idea or that it couldn’t be a great idea with refinement/improvements though-it could be an awesome dump load for when your battery bank is full. Most people use a water heater for this, but if your solar array is big enough it could do both. |
Never make another person a priority when they merely see you as an option...
"Some People Are Like Slinkies. They're Not Really Good For Anything, But They Bring a Smile To Your Face When Pushed Down The Stairs."
"Some People Are Like Slinkies. They're Not Really Good For Anything, But They Bring a Smile To Your Face When Pushed Down The Stairs."
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Originally Posted By TheOtherDave: I just skimmed it, it’s a neat idea-I think I understand that you are using a solar panel to heat the terracotta in the oven up so that you can cook even after the sun goes down. One fly in the ointment is that directly connecting the oven to a panel doesn’t get nearly the best power that the panel is capable of-really only about 2/3 of it. It’s not a huge deal as MPPT controllers are pretty inexpensive in the power ranges we are talking about, but you would need a battery of some kind to make it all work. (With an MPPT controller as they need a battery load) I can see something like this working fairly well, but it wouldn’t be the same as using a conventionally powered oven. No matter how hot you can get the oven, it is still a matter of mathematics in terms of how much energy in is needed to fully cook X amount of food mass. Such an oven might do a great job on a low mass item like a Hot Pocket, but an apple pie? Sure, 100 watts will get an insulated terracotta box pretty damned hot, but putting a chicken in it will cool that terracotta right off and then you are back to trying to cook a chicken with 100 watts when normal toaster ovens need 15-1800 watts. Most of you guys have seen my thread on my solar ovens, a lot of the same physics apply only they cut out the middle man of the solar panel and the direct connection efficiency issue-my solar ovens don’t work after dark though-well, two of them do because they have 12V heating elements for that.. Not saying it’s a bad idea or that it couldn’t be a great idea with refinement/improvements though-it could be an awesome dump load for when your battery bank is full. Most people use a water heater for this, but if your solar array is big enough it could do both. I think he is using it more like a slow cooker. He does say that you need to get the temp up before using it and not to use it with frozen foods. Why would he need a MPPT controller? Believe he is just connecting the panel directly to the heating element. |
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Originally Posted By DaGoose: I think he is using it more like a slow cooker. He does say that you need to get the temp up before using it and not to use it with frozen foods. Why would he need a MPPT controller? Believe he is just connecting the panel directly to the heating element. Because solar panels need to be loaded to their most efficient voltage drop under load to give their best-it’s a difference of about 30% in output.. If you put a dead short (not that heating coils are a dead short) across a panel it makes basically zero power… an MPPT controller calculates (or just uses a fixed voltage if it’s cheap chinesium) the best voltage under load to get best power. They need a battery to do this though, so one would have to be a part of the plan if they were to be used on one of these ovens. ETA: even supercapacitors would work |
Never make another person a priority when they merely see you as an option...
"Some People Are Like Slinkies. They're Not Really Good For Anything, But They Bring a Smile To Your Face When Pushed Down The Stairs."
"Some People Are Like Slinkies. They're Not Really Good For Anything, But They Bring a Smile To Your Face When Pushed Down The Stairs."