Solar Thoughts blog

Food for thought

A personal blog about DIY Projects, Technology & Solar Power

Low Voltage Solar Panels can cook food directly – And why it matters

Did you know it’s possible to cook food directly off low voltage solar panels? No inverter, no high voltages, no battery, no charge controller. It’s technically feasible, and I have done it several times now with prototypes developed in my solar workshop. The simplicity and efficiency of such a setup is nothing short of astounding.

Early test of PV2L solar electric camp stove boiling water in a stainless steel pot off of direct DC solar power

Fig1. 2022 early test boiling water

No, these prototypes don’t use high voltage DC (Direct Current), that’s a lethal electrocution risk, an arcing and fire hazard plus incredibly stupid. This is not worth dying or going to the hospital over. Instead, I used a safe low voltage DC range. In that state, DC really shines for cooking.

If you are a survivalist, Van/RV dweller, off the electrical grid, a DIY solar enthusiast, or just someone who enjoys cooking food with clean energy, this concept might belong on your list of DIY projects. This type of technology sits between the mirror (solar thermal) based solar cookers, and the normal setup typically powered by an inverter and batteries.

My goal is to promote the idea of Direct PV Solar Cooking so we can buy such equipment straight off the store shelf. Ideally it should be mass produced, safety-tested, UL listed, etc.

Of course all of these prototypes can run directly off a battery bank if needed, which is still a nice capability. But using direct PV power is far more interesting and “purist”.

PV2L cooking is more convenient than solar thermal cooking (the kind with mirrors or evacuated glass tubes) because with a pair of wires, one can cook indoors out of the wind and weather, in a normal kitchen environment.

Why It Matters

In 1996, I suggested to a grocery store that people should be able to order their groceries online, and pick them up or have them delivered by a fleet of vehicles. In 1992 as a young boy I suggested to my father several inventions, all of which exist today as off the shelf products. Of course I didn’t get paid for that.

In 2022 I suggest efficient PV2L (PV To Load) (PV means Photovoltaic) solar electric DC cooking is the future. Charge controllers, batteries and inverters are all wear items with very high costs. Why work your expensive inverter, batteries and charge controller when you’re just cooking food? What if there is no fuel or propane for normal cooking, and normal solar power equipment is in short supply as well? Times will change. Why be limited to the Charge Controller / Battery / Inverter paradigm?

It is more efficient to run the PV straight to the load in many cases. Unfortunately the industry hasn’t really caught on yet, but hopefully they will soon.

My Search for Direct Solar Electric Cooking Solutions

I spent years looking for a way to cook directly off of solar panels with kitchen-level dissipation (power level). Bottom line, I was repeatedly disappointed, finding no options. There are a variety of small 12V warming or cooking appliances, but nothing with high power output. Affordability was a requirement as always, which limits options further. Yes there are very expensive cooking systems intended for yachts and ships, but those are out of reach for the average person.

First Taste of Success

Early test of PV2L solar electric camp stove cooking chicken in a stainless steel pot off of direct DC solar power

Fig 2. Early test cooking chicken in a pot

I worked myself to bits experimenting in my solar powered workshop with various setups. I spent a lot of time and money, and went through a lot of trouble trying to find the answers. It had to be DIY friendly and cheap. To make a (very) long story short, in late 2022 there was finally a bare bones prototype on my workbench ready to be energized for the first time with LV (low voltage) DC fed straight from a 1250 watt solar panel array outside my shop. There was no induction circuit or complicated electronics. But would it work?

Unwilling to risk bringing food and crumbs into my clean workshop, I successfully boiled water several times using a prototype camp stove-like setup right there on the workbench.

Not being a cook, I figured, if it can boil – maybe that’s enough to cook food. This first prototype did not have as much dissipation (power) as I had hoped, but it still worked, and got very hot. The power level easily exceeded those small 12V appliances that are available. I couldn’t believe it. No high voltages. No inverter. No battery. No charge controller. Just pure solar electric cooking power.

The very first public test of what I call my PV2L Solar Electric Camp Stove was recorded on YT – unfortunately it got very little attention for such a cutting edge concept. That was very disappointing, but doesn’t invalidate the concept at all.

Earling testing of DIY solar electric heating elements in my workshop 2022

Fig 3. Early test of heating elements in my workshop

In the first test, I was unwilling to put much food in the stainless pot as I doubted the idea would work. I settled for a few pieces of chicken, some olive oil, garlic etc. But the concept proved sound, cooking the chicken very quickly, in fact I had to keep adding water to keep the experiment going or it would boil dry after a short time. The weather was cool and windy, but there was still enough heat to cook.

I did not use anything too complex to do the test – to prove the point, I literally set the stove on the grass and plugged it into my solar array outside the shop directly. In my haste to try the setup, there wasn’t even a circuit breaker or fuse, and the wiring was exposed beneath the stove. I had to cover the panels with a blanket to attach / detach the stove to avoid harming the MC-4 connectors.

And it worked. No battery or complex setup. I could have cooked just about anything in that pot.

Note I did not show all the details in the video. The wiring and build quality was not up to standards let’s just say, and I didn’t want to promote hazardous practices. Such as, how to burn your house down with solar panels.

In total, I now have 5 different solar electric camp stove prototype setups, each with different power levels. The highest power rating seemed to be too much, but could be useful for cooking larger amounts of food. The devices are relatively simple, robust, and lightweight. They can run off of a few solar panels on the roof of a Van or RV, for example. One of the problems is making it DIY friendly and safe, because cooking appliances can represent a severe fire risk.

How About an Oven Then?

Weeks before, I had acquired a discarded Toaster Oven that was not working. I kept thinking, what if I put my idea into a PV2L oven format, and used it to bake and toast directly off the solar panels? It seemed to be out of reach, how could that be done while still meeting my requirements of affordability and DIY friendliness.

Prototype of rebuilt PV2L solar electric DC oven sitting on my workbench

Fig 4. Rough DC oven prototype sitting on my workbench 2022

I tore the oven apart and modified it, adding a few experimental efficiency enhancing tweaks along the way to see what would happen. Existing oven components had to be removed. I knew the electrical components inside an AC toaster oven were absolutely unsuitable for Direct Current (DC) and straight up hazardous when used on anything but AC voltage due to welding, arcing behavior of DC. Even lower DC voltages can arc aggressively and start a fire. But the outside enclosure of the oven was attractive, sturdy metal, fairly well made and I could not really duplicate it. With proper DC components and wiring installed, I thought it should be suitable for a DC oven.

Rebuilding an oven for DC can be quite a task. Part of my research in the solar workshop was making custom heating elements from materials such as Kanathal A1. But it’s hard to get heating elements working just right under a variety of conditions, and of course I burned out some of them. Furthermore, exposed heating elements can start a fire if they contact grease or oil from the food.

Finally the oven was in a state I could test it in, and it was time to give it a try. I energized it from my 1250w test solar array through a circuit breaker. A few minutes later, I realized it was getting very, very hot. I used a thermometer and found the temps quickly exceeding 300 degrees Fahrenheit.

So this led to the first public test of my PV2L direct DC solar powered electric toaster oven. That’s quite a mouthful, but all those terms are a valid description.

A family member helped me by preparing a small meal of all beef hot dog, some vegetables and spices (termed “solar hot dogs”). I put it in the solar electric oven. It was placed in the oven after a preheat. The food cooked astoundingly well. It was a total success – beyond my expectations.

Summary, Current Status and Future Plans

From the performance of the prototypes I have tested, it is clear this concept is worthy of consideration and effort. In the current state of the world, the idea has not gained much traction yet. It’s still very early.

I am exhausted at the moment but plan to put more work into the project.

Solar electric oven cooked food PV2L PV to Load Oven taste test

Fig 5. History made, tasting the first meal cooked in the PV2L solar electric oven

In the mean time, I am hoping by blogging (more accessible than producing videos) about it, the concept will gain more acceptance and interest, which would fuel more development work. And hopefully a company will pick up on the idea and create a safe, affordable and robust mass-produced product we can all buy. And it needs to be UL-listed for safety.

My goal is to bring the idea to the DIY solar enthusiast, but not in a way that is dangerous or promotes unsafe build practices.

If interested, the videos I have so far of these prototypes are posted below. If you like this idea, please spread the word and promote it. Hopefully companies will pick up on the idea and bring new products to market.

Due to lack of exposure I have not yet recorded a how-to-build video. It’s too much work when basically no one will see it or benefit. In fact, what WILL happen is a large channel will steal the work, present it as their own, and run ads on it. I’m just not willing to support that. It’s a sign of the times. If I could show the video to at least 100,000 solar enthusiasts right away, I’d be all for it!

At least I have the concept and prototypes documented – it’s a start.

Thanks for reading! DD

First public test of a PV2L DC solar electric oven – Cooking Food:

First public test of a PV2L DC solar electric camp stove – Cooking Chicken:

About the Author:

DD Solar (a nickname) has over a decade of experience in solar power and renewable energy, and over 25 years of experience in the Information Technology industry. He currently operates a YouTube channel called Solar Power Edge (formerly known as DIY Solar Power Edge and DD Solar Channel) and documents some of his projects and prototypes there. (C) 2022 DIY Solar Power Edge channel / DD Solar channel / SolarPowerEdge BLOG All rights reserved. We reserve all rights.
%d bloggers like this: