How to Build a Solar Powered Electric Oven
13 comments
·October 25, 2025nwhitehead
qwerpy
I had fun doing this over the summer with a 100W panel, a 1kWh battery (1500W max output), and various cooking appliances: rice cooker, hot water kettle, instant pot, induction cooktop. On a sunny Pacific Northwest day I could charge the battery around 50%, more if I rotated the panel diligently. Rice cooker and hot water kettle (5L) would use about 40-50% of it per usage. So during the summer it was handling all of my power needs for those two appliances. It was always fun getting to full charge and frantically finding novel ways to "not waste" the sunlight. Charging my power tool batteries, etc. One time I even charged my EV 1% but that wasn't very practical.
Some other interesting things I learned: the battery passively eats about 5-10W, and on a cloudy day the solar panel would only get 10W during the day. So in the cloudy PNW winters it can't even maintain the battery let alone charge it. The inverter eats another 30-50W or so, so you have to turn it off when you're not using the AC outlets. My battery lets me separately power AC and DC (USB-A and USB-C) so I was charging devices via USB and not wasting energy powering the inverter.
buckle8017
There are now commercial ovens with LiFeO4 batteries in then that do basically just that.
Except they're stupid expensive.
wopwops
Why do the images look like someone took pictures of dotmatrix printer output?
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Update: for whatever it's worth, I just asked the Magic 8 Ball (Perplexity):
Low-tech Magazine uses the option to display images as dithered primarily to reduce the energy consumption and data load of their website. Dithering is an old image compression technique that reduces the number of colors in images to just a few shades of gray (black and white with four levels of gray), which dramatically decreases the file size. The black-and-white dithered images are then recolored via the browser’s CSS, which adds no extra data load.
This approach makes images roughly ten times less resource-intensive than full-color high-resolution images, which supports the magazine’s goal of having a low-energy, solar-powered website. However, some images, such as graphs or those with crucial color information, may become less clear under dithering, so the website offers the option to turn off dithering for individual images to reveal the original, heavier images. This balances energy efficiency with the need for clarity when visual information depends on color or detail.
Thus, the dithered image feature is both an energy-saving measure and a distinct stylistic choice that aligns with the philosophy of reducing the environmental impact of web usage while maintaining visual storytelling appeal.
NaOH
Probably best to read the Low-Tech Magazine site About page explaining what they do as a solar-powered site:
loloquwowndueo
You can also find this information in the web site itself: https://solar.lowtechmagazine.com/about/the-solar-website/#h...
kamranjon
It would seem strange if that was the purpose since the first photo on the website is ~40kb
adrianN
With the panels I have on my balcony I get about 200 watts even on overcast days. I would love to have appliances that were optimized for lower peak consumption. But many appliances like the fridge have low average consumption but high peak consumption so that while the panels on average produce about as much as I consume per day in reality I still have to buy power from the grid.
electroglyph
batteryhookup is a great source for used batteries, it's pretty affordable to build your own setup to run stuff like a fridge
pluto_modadic
wonder if you could increase fire resistance by moving the grout layer so it's not touching the bottom cork except in key spaces with a more effective insulator?
oritron
I think some simple MPPT circuitry would be a smart investment for this, rather than a fixed resistance connected directly to a solar panel.
bigiain
It's from Low Tech Magazine. A low tech solution is not surprising. Chasing 20 or 30% solar generation efficiency gains isn't really something all that relevant when you're building an oven that you're going to leave switched on all the time whether you're cooking or not.
buckle8017
An MPPT would double the cost of this setup.
This is fun, I'm curious to try it.
An alternative that I experimented with and found to be very usable is one solar panel, a small camping battery ("portable power station"), and an Instant Pot. The total cost is not super high. The Instant Pot is power efficient and can cook a lot of food at once. Since it's battery powered you can start any time the battery is charged.