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  • Even if insulated, isn’t this setup always heating the home? The insulation slows down the heat transfer but if I’m following correctly it’s basically running the heat element anytime the sun is up. I think this would be counterproductive in my climate as I’m cooling the home most of the year which is an even more energy intensive process
    by conductr
  • I think some simple MPPT circuitry would be a smart investment for this, rather than a fixed resistance connected directly to a solar panel.
    by oritron
  • Why do the images look like someone took pictures of dotmatrix printer output?

    ---

    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.

    by wopwops
  • Great project and build. I wonder if using a small fan would not help energy transmission, which is eventually the goal of cooking. It may also make the oven work like it’s at higher température while not consuming much energy. It would discharge energy from the walls faster using convection in addition to radiation.

    Plus, you can experiment with tray materials depending on what you want to cook.

    Suggestions inspired by my experience with convection/classic oven and copper pizza plates

    https://www.italiancookshop.com/products/hammered-copper-rou...

    by 0wis
  • Just as a note pressure cookers like the Instapot are rated at 1000wh but they don't use that all the time IIRC — only initially when building the pressure. In simple terms it's like using 1kw for 10 - 15 mins and not an hour. So on average very efficient.

    Has someone measured the time for max usage and average usage? Could be a good alternative with a 1kwh lfp battery with a lot of juice left over after pressure cooking(no pun intended)

    by ghm2180
  • 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.

    by nwhitehead
  • >lower cooking temperature of about 120°C

    At what point is it easier to just use a microwave? For all the effort to biuld an insulated box, a small microwave consumes maybe 600w, easily doable with batteries and an inverter. Microwaves also get hotter (useful if you want to do more than poach food at 120c).

    Actually, forget the inverters. It turns out loads of 12v/24/48v microwave ovens exist for the RV market.

    by sandworm101
  • This article references a 2023 article about lithium battery costs with price at 750 EUR per kWh (approx 12V 100Ah) for 30 years life couting 3 replacements if I read correctly note 5:

    https://solar.lowtechmagazine.com/2023/08/direct-solar-power...

    These days 1 kWh of LFP battery is 70-150 EUR depending on the brand, so far lower than referenced. And LFP cell lifetime is probably 20 to 30 years.

    In a system it means that 1 kW of solar PV panels is about the same price as 1 kWh of battery, and similar lifetime.

    by guerby

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