Ultra efficient solar electric cooker! 20 Watt Solar Panel can cook an egg with diode chain

[@turboslag]

Basically this is a diode potential divider. Each diode will drop around 0.6 volt across it, depending on the specific diode, this is for silicon diodes which is effectively the only type that will be used today. As long as the voltage across the whole string doesn't exceed the max reverse voltage of an individual diode, they will quite happily conduct like they would in any circuit. The number of diodes in the string, or divider, determines the current flowing with a given voltage, if that current doesn't exceed the max forward current rating of each individual diode they will function without issue. Current X voltage = watts dissipated in heat. Theoretically, one diode with a sufficient current rating would dissipate the same heat as a number of diodes with a lower current rating. If that one diode didn't exceed it's max junction temperature, it would work equally as well, but would probably be more difficult to incorporate into a practical design. Maybe say 4 or 6 smaller current diodes in a package with an external metal tab would be easier to use, as they could be screwed or bolted to an aluminum or copper dissipator, which could be used to transfer the heat to container. All semiconductor devices dissipate heat when in use, normally that is undesirable but unavoidable, and is treated as waste that must be thermally managed, hence heatsinks and fans found in many electronic devices. So this is an interesting perspective on the subject!

[@solarpoweredge]

@turboslag I found that DC fans can receive a voltage supply lower than the solar panel, by connecting across some of the diodes. Diode current is exponential of voltage, so that's why they work so well with solar panels, a current limited source.

[@wpgenlighten4truth2]

That is SOOO Amazing, Thank You For Sharing your Work ....I ordered the diodes and I Have some ideas, when I have them built I will link You the video .....AWESOME...!

[@solarpoweredge]

@wpgenlighten4truth2 welcome :) have fun with the diodes, I think they are amazing

[@lexloose2112]

excellent idea, keep it ongoing! I'm going to be playing with the idea. thankyou from the UK

[@solarpoweredge]

@lexloose2112 Thank you! and hello from US :)

[@iosifferencz5432]

Cu ajutorul concentratorului solar chiar si Fresnell randamentul poate este mult mai bun ,daca aveti posibilitate faceti o demonstratie Oricum va multumim pentru ce ne prezentati❤

[@solarpoweredge]

Bună ziua domnule, intenționez să încerc aceste lentile mai târziu, mă bucur că vă place videoclipul, aveți grijă :)

[@timbrown9305]

Water heating is a great storage system on a solar system. This would work for a hydronic heating system with a huge storage for all night operation or even 2 day backup at elevated temperature storage with a mixing valve. No batteries required except for small efficient hydronic pump like Grundfos.

[@solarpoweredge]

@timbrown9305 That is true! I'd like to build a dedicated solar heating system that uses water tanks, hopefully I'll have the chance

[@TinyGoHomes]

You could make one that will heat a loop and it could power in floor heating. Can’t wait till I can start doing things like this. I’m 3/4 done or king on the shop, my inside winter project. I’ll have everything I need to start having more fun this spring.

[@solarpoweredge]

@Nofukzgiven Yeah good thinking. I wish there were big vacuum insulated containers about 10 gallons (they'd probably cost a lot). Your shop sounds like fun. I am hoping to start a few new workshop projects in spring - if things go well enough

[@Luke-san]

Very very interesting. Just found your channel. Also saw your new video and it seems next to the silicium and Schottky we now have the idiots diodes. Small anecdote. I just purchased blocking diodes from China in mc4 connectors since I use different kind of play panels that I purchased over the years. The panels are connected in parallel so safety first. When I ordered them I had a choice of 10A, 20A or 30A with minimal price difference so I went with the 30A ones. When they arrived I measured the fwd voltage. (I already had my own Schottky blocking diodes but not in a waterproof connector and the price was really good for the ones I purchased.) But measuring.... 0.55V I realised that these were regular diodes and not Schottky diodes. I used my bench power supply and set the current to 15A and the voltage drop was 0.8V and I could actually evaporate water touching that diode. P=uxi ... So the damn thing was 'waisting' 12 Watt which went into direct heat. Remember this was with the connector open. Imagine with a string pushing 20A thru in an enclosed connector I smell kind of a disaster waiting to happen. So now I have a couple of diodes to be used for heating purposes. Actually a very neat usage of a not perfect diode and also 'abusing' them so that the panel is delivering the max ppt. Now going to watch the rest of your videos. Sharing and showing is building up knowledge. Thx for that!

[@solarpoweredge]

@Luke-san Hi, glad you found the channel... thanks for subscribing. I always felt YT should be about sharing knowledge vs. entertainment. Oddly enough I bought quite a lot of diodes that were listed as Schottkies - but they were not! Oh well they are still useful

[@daveswords2112]

Brilliant video I'm hoping to grow seeds off grid and need to beat the soil with soil warming cable. It's a big area typically 5feet by 2 feet Do you think this would work or connect solar of direct to soil warming cable Keep up the great research

[@solarpoweredge]

@daveswords2112 Hello, I think it's possible to make such a heating element, is the soil in a separate container or indoors? The diodes and wires should be protected from the dirt and moisture. Otherwise, they might corrode and become damaged. But yes I think it would work

[@daveswords2112]

Yes sir thhe heating diodes can be protected from the soil and moisture. Normally you run heat cables in wet sand then place seed tray on top. Not sure how you would get a good thermal coupling with diodes Thank you buddy

[@solarpoweredge]

@daveswords2112 You are welcome sir. Thermal is certainly a challenge. Perhaps some kind of pipe with the diodes inside and heat sink compound or sealant to help the diodes connect with the sand. This is all highly experimental stuff so who knows whether it would work. I am still testing different kinds of diode heating elements to see what works best

[@daveswords2112]

You just triggered an idea. Vacuum forming the diode array in plastic. Similar to how woodworkers. vacuum seal. When Veneering timber. Thanks

[@solarpoweredge]

@daveswords2112 That sounds pretty cool, thinking outside the box for sure

[@aldymcpndg14]

Hi there, great work. Can a battery used to power this diode heater? If yes, do i need to use boost converter to mimic the solar panel? Thanks

[@solarpoweredge]

@aldymcpndg14 Hi and thanks :D diodes have no major resistance to current flow, therefore if you must use them w/ a battery, current-limiting is an absolute must. This might be handy for a dual-use scenario, where the cooker needs to accept direct solar PV input and still accept a battery input. It's good to think outside the box about different scenarios, that's how new things get invented :)

[@itsjenna1560]

Hello!! Im a Highschool student and we wanna make a prototype for our science project in using solar panels for portable water desalination.. we just aren't completely sure on how to make something like this so I was hoping if you had some kind of idea or advice you wanna give us since we are a bit lost, we wanna use the solar panels to heat the water when it comes to the desalination process... and we wanna make sure its drinkable..

[@solarpoweredge]

@itsjenna1560 Hi! I've built a water distiller with this idea, it's 100% possible. But using diode strings is rather complicated and tedious. For a first project, what I'd recommend is to take a different route - a 12v heated cup. Those are easy to find and they work pretty well. Here's my video about the heated cup, you can see the water was boiling quite vigorously. Make sure teh voltage doesn't exceed about 12-13v or it might overheat! Hope this helps! kzbin.info/www/bejne/Y4LXmYOFial_ibs

[@deanchapman9604]

Is there a possibility of coming up with a way to make a instant hot water heater instead of heating a hot water tank?

[@solarpoweredge]

@deanchapman9604 Hi, it would be technically challenging, but I think 100% possible. Great idea btw!

[@seddiqullahkhaliqi5916]

Will you elaborate the diod connections. Please

[@solarpoweredge]

@seddiqullahkhaliqi5916 Hello, they are a series string of diodes matched to the solar panels approximate Volts-max-power range. Of course it is not perfect regulation, but acts very similar to an MPPT circuit for very cheap price. To see earlier experiments, tests and explanations, please try these 2 videos: kzbin.info/www/bejne/bHWTkoijoLqEibM kzbin.info/www/bejne/amO7epV-dp53rJI

[@LienoGenesis]

I think with Monocrystalline panels you would get more power out of them in cloudy days. they are known for that

[@solarpoweredge]

@LienoGenesis It would be interesting to find a 20w mono panel. Even a couple of watts would make a difference

[@ttucker2010]

This is awesome! I'm wondering if the diodes would degrade quickly with the cycle of heating / cooling. Any thoughts on that?

[@solarpoweredge]

@ttucker2010 Glad you like it :) From the research I have seen, they usually last a very long time. Cheap to replace too. But overheating can destroy the diodes of course. Honestly I never felt like abusing diodes this way, but it's so interesting I couldn't help but give it a try! And the rest was history...

[@ttucker2010]

@solarpoweredge Please tell us what diodes you used, how many and they are wired in series right? I would like to duplicate your project. Did you put any protective cover on the diodes? Is that necessary? Maybe you can do a video on the build with all the details. Thanks!

[@solarpoweredge]

@ttucker2010 1) Both cookers have normal unbranded silicon rectifier diodes, axial package 2) the number of diodes depends on the vMP range of the solar panel, so just add however many for the voltage you would like to use 3) they're all wired in series. Regarding build video, I am already running flat out so wasn't able to but perhaps in the future can do it??

[@ttucker2010]

@@solarpoweredge Thanks!! I'll give it a try.

[@solarpoweredge]

@ttucker2010 Welcome sir!

[@canterburyworkshop5631]

It's been some 40 years since I studied electronics, and I'm in the process of developing a solar powered sand battery to supplement heat to my gas boiler system. But, now I am looking at using a 90-plate heat exchanger that can utilize 12V solar to heat 16-gallon distiller pot to provide 140 - 190F to heat the plate exchanger. I see you mention a 100-200a power rectifier diode with heat sink to provide greater heating capability. Can anyone guide me as to how to apply such a diode to do this?

[@solarpoweredge]

@canterburyworkshop5631 Hi, bigger diodes are tougher and should take more heating work. For that reason I been researching them as much as possible. Right now my shop is being heated in part with large power rectifier diodes (not axial type). For your application, have to think about how to get the heat out of the diode and into the water. There are lots of options in that direction... In my tests, diodes can handle 100(C) just fine, so 140-190F is totally possible I think. Note: the bigger diodes can get expensive... so I imagine at some point the cost might outweigh the benefits. For the last heater I spent $50 on diodes, whereas nichrome might cost $1. However I may have solved this in a future video... we'll see I guess :D

[@canterburyworkshop5631]

@@solarpoweredge Thank you for your quick reply. I will keep learning more about power rectifiers online, and try to quickly update my lost electronic knowledge.

[@solarpoweredge]

@canterburyworkshop5631 No problem!

[@markirish7599]

Could you add a link to the diodes

[@solarpoweredge]

@markirish7599 Hello, sure I have added links to example diodes in the description text

[@stephenbaker3680]

Just have a food temp sensor inserted into the meat to verify when 135-140°F hits.

[@solarpoweredge]

@stephenbaker3680 That would work

[@alhumble8175]

Did you use 3A or 6A diodes? Thanks

[@solarpoweredge]

@alhumble8175 Hello, this thing is tiny so I used 6A diodes. But even 3A diodes might work. Just make sure the heat gets transferred into the water, otherwise the diodes get super hot and burn up

[@Buddyelvis1-2022]

US government wouldn't allow such an efficient device for open sale.

[@solarpoweredge]

@Buddyelvis1-2022 Very likely, probably need to upgrade it to 1kW and sell it as the "instant egg cooker"

[@priestesslucy]

​@@solarpoweredge fr, the dash egg cooker pulls _450 watts_ based on the label! In cloudy country where I live you could need over 4kw of panels to generate that current some days, particularly Nov-Feb 😱 It's actually pretty energy efficient to use the thing to 'boil' up to 7 eggs at once vs boiling a pot of water, but the design relies on non-pressured vented steaming (of a tiny quantity of water granted) so it's easy to see it's nowhere near as efficient as it could be.

[@solarpoweredge]

@priestesslucy Wow 450 watts that is huge.... a while back, I made a bigger version of this, it only uses about 25 watts and can boil several eggs at once or heat food etc.

[@mariquevandermerwe9301]

What about the hydrogen and oxygen that is generated between the diodes

[@solarpoweredge]

@mariquevandermerwe9301 There is no electrolysis taking place, the diodes are isolated from the food being cooked, while being thermally anchored :)

[@argellaguardia9390]

Your video caught my attention pretty well and forced me to become your new subscriber. Been looking for projects related to direct current from solar panels. Hopefully to replicate some of your projects. From the Philippines.

[@solarpoweredge]

@argellaguardia9390 Welcome and thanks for subscribing :) I hope the content will be helpful. Direct solar cooking does not get a lot of attention right now, but I believe it can be useful to many people. It solves the need of repeatable, renewable, long-term cooking (indoors) without fuel (and at lower entry costs)

[@argellaguardia9390]

@@solarpoweredge - indeed! And you put into action your great ideas that can be beneficial to millions of families around the world. Thank you so much!

[@68HC060]

Hard boiled egg: 10 minutes at 100 degree Celsius - that's fairly easy to remember. 😃 -But I guess the water in this video is just shy of 90 degree Celsius - certainly enough to cook an egg.

[@solarpoweredge]

@68HC060 Now that's something I can remember! Apparently I overcooked this egg ... but it was still edible lol

[@venkateshachary9949]

Can we make 5 kw heater from this diodes

[@solarpoweredge]

@venkateshachary9949 Hi and yes, there are 2 ways at least to do so: 1. Most expensive option is 100-200a power rectifier diodes with proper heat sinking. 2. To heat my workshop, I have finally combined a 50 amp power diode string with standard resistance heaters. This means the solar panels will stay near the solar panel Max Power voltage, the resistance heaters will run at this voltage too, and the diodes will extract the remaining heat while also regulating the voltage - I will try to share this setup as soon as possible

[@cgmarch2359]

I tried today a string of 10a diodes on my small solar panel (20v 4amp max at mptt) The diodes draw as much power as the mppt solar controller. I just need to try in poor conditions. The big issue is cooling .. maybe I will try with the allu profiles

[@solarpoweredge]

@cgmarch2359 Nice job... getting the heat out is the toughest part in my opinion. Too much and they burn up. Testing some aluminum heat sink ideas at the moment

[@cgmarch2359]

There is the ideea to parallel them to share current.. and with a good radiator maybe it will work?

[@solarpoweredge]

@cgmarch2359 Yes it will work, the current will be shared

[@cgmarch2359]

Ok I tried it with very little sun.. just 3w and again works the same as mppt. Basically as long as you match the number of diodes with the mppt volts.. it will work and draw the max power

[@solarpoweredge]

@cgmarch2359 Amazing, it works so well. Great research you're doing there :) This technology really needs to be developed further.

[@user-mz7hb1dq5x]

shark tank needs to see this one.

[@solarpoweredge]

Maybe they'll click on this, who knows :)

[@CharlesGwinn-ep9pb]

Your diode string idea may be a patentable idea.. ..cheap way of matching panel power to the load to maximize efficiency. My idea is to solar cook oatmeal, rice , beans in those 12volt stainless steel thermoses they sell on Amazon. I successfully heated water in one to 170+ degrees and made ramen...about 30 min. So I was thinking...what if you built a ?6 inch thick styrofoam cube for the cooking vessel with small hole for steam to escape and a drip tray to let water condensate drain out through a small bottom hole. Also would need a temp switch to turn solar/batt power on/off so as not to burn up heat element. Kindof a hybrid haystack slow cooker. Trapping all that heat should allow the food to cook much faster and use a fraction of the energy.Doubling insulation r value results in half the heat loss!

[@solarpoweredge]

@CharlesGwinn-ep9pb yeah diodes have been working amazingly well. I made larger diode cookers and projects but they are not on video. Maybe by this winter. I like your idea about insulation. There are a lot of things to try. Keep on experimenting!!

[@stephenbaker3680]

Dude! 175°F PLENTy! When meat/chicken internal temp hits 135-140°F range a few min food experts say you ARE cooking & after enough time..yer DONE!

[@solarpoweredge]

@stephenbaker3680 Right... I'm no cook, but with as much as 212F, this thing should cook a lot of different foods and certainly can heat up a can of soup easily

[@Sammyflopped]

WHAT KIND OF DIODES ARE THEESE

[@solarpoweredge]

@Sammyflopped Hello, they are very cheap Silicon Rectifier diodes. There are links in the description. Just make a string of them in series to drop the appropriate voltage. Make sure they don't get too hot, I keep mine around 100C. Please see my other diode videos for explanations of voltage drop, hope that helps :)

[@Sammyflopped]

@@solarpoweredge alright, also can the run on dc also ?

[@solarpoweredge]

@Sammyflopped As long as the DC is current limited to what the diodes can handle, yes. Diodes will consume all the current (amperage) available. A solar panel might put out 3 amps, but a battery could put out 500a and burn the diodes. Matched diode strings are best suited to direct DC from solar panels because of their "MPPT-like voltage regulating" properties. If running off of a battery, that need goes away and perhaps a resistance element is better suited. I like the idea of having a flexible 12v DC option on a diode based cooker, so perhaps a CC-CV boost converter would be one way to achieve this. Either that or have a dual-element cooker; diode chain for solar input and a separate resistance element for 12v operation. Thinking in survival mode, I tend to prefer the simplest options with little to no electronics.

[@solarpoweredge]

@Sammyflopped Also I neglected to explain this in my video: diodes are temperature sensitive, so the diode chain should be configured for the operating temperature you need. At 60C the diodes will drop more voltage than at 100C. You might notice this as they warm up. Therefore, if you are boiling water, use the correct number of diodes for 100C operation for best results. The downside is they won't pull as much current while initially warming up. In my tests I didn't find that to be a huge problem though.

[@Sammyflopped]

@@solarpoweredge thank you for explaining this stuff!

[@cronicjohnson]

So many 10watt diodes do i need for a 550w panel. To make a heater for my outdoor cat house

[@solarpoweredge]

@cronicjohnson Hi, I recommend using bridge rectifier or power diodes that have a "tab" or a metal case with a hole for attaching to a heat sink. Then find a good sized heat sink that can handle about 400w probably. The number of diodes is calculated by the solar panel vMP (max power voltage - need to find out what that is). Each diode can drop about .5v depending on the type AND depending on the temperature. So some hands-on experimenting is required to find the right number of diodes. Also need a few spare diodes available just in case you want to change the operating voltage/temp or if one burns out. Hope that helps

[@cronicjohnson]

@@solarpoweredge my plan was to make the floor into a sand battery to hold the heat from the diode array. Not sure I would need a heat sync at that point

[@solarpoweredge]

@cronicjohnson It's worth a try... I want to make a sand battery as soon as possible to test the idea. Diodes need to be kept around 100C or less for best longevity, I am not sure exactly how to accomplish that

[@simonrines4334]

@@cronicjohnson I was thinking of doing the same - want to make an off grid shower - so thought 'capture heat in the day in a sand battery and run a heat exchange into it t heat the water. I was thinking I'd be using heat pipes, but this is interesting. One thought, transferring heat from diodes to sand might not be highly efficient because sand has low thermal conduction compared to water. Water is not ideal because of corrosion to diodes, steam build up, evaporation etc - how about having a central container of wax in a tin holding the diodes? Presumably it wouldn't harm the diodes, but would offer efficient heat transfer

[@solarpoweredge]

@simonrines4334 Wow lots of good ideas in here... just thought I'd drop in some thoughts for your consideration. Another strategy is an "immersion element" with copper tubing or metal case. I built a portable solar electric hot water heater HWH using this idea. The heating element is sitting right in the water, runs about 15-17v and 100w solar panels. It goes with my 12v camp shower. Great for emergency use! If you get the diodes in close contact with the water, then that heat can go into the water quickly, for low cost. The diodes need not get too hot. The diodes don't have to be directly exposed to water, but encased within metal. Insulation can hold the heat. Of course, sand can hold extreme temperatures, unlike water. But for hot showers only, probably don't need/want water that hot! I hope to present the HWH build as soon as humanly possible... there are so many ideas and projects to do these days

[@Sammyflopped]

BRO START MASS PRODUCING AND SELLING PLEASE

[@solarpoweredge]

@Sammyflopped Right on! I hope these make it to the store shelf

[@redzebra6688]

@@solarpoweredge Sammy is absolutely right! Couldn’t agree more! This is the future! Thank you Dave!

[@solarpoweredge]

@redzebra6688 Welcome :) I am so glad there are other people who understand this kind of stuff... it's super motivating!

[@steveadal4735]

Lovely Sir the diodes r on amazon?? ❤❤❤❤❤❤❤❤❤❤❤❤❤❤❤❤❤❤❤

[@solarpoweredge]

@steveadal4735 Yes sir you can use standard silicon rectifier diodes. Link in description or just search Amazon etc. Note - for a small container, the smaller diodes are easier to fit as it takes well over a dozen of them. I like to use 6 amp and 20 amp diodes mostly. I used the smaller diodes here, as the 20a are too physically large