Posted by surprisetalk 10/25/2025
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.
As it stands it's enough to power the country for about two minutes, but that's two minutes gained in a year.
In the commercial space there's a total of 4.3GW of peak output commissioned to be deployed before 2030. That will greatly help in shaving the afternoon increase in electricity usage.
https://www.theguardian.com/australia-news/2024/feb/22/green...
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.
Slow cooking almost always gives you excellent results with vegetables, meat or fish. There is already a market of crokpots, sous vide and steamers, that I wouldn't dismiss as "poach food".
And for things like a pizza or crispiness in general, that need higher temperatures, I doubt you can get decent results with a microwave.
The usual 180°C / 350°F set has more to do with convenience (highest temperatures that doesn't burn the outside before the core is cooked) for cooking things as quick as possible, than tastiness of the food.
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.
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.
Except they're stupid expensive.
Similarly, I think there’s a niche market for a propane-powered espresso machine.
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)
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...
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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.
I suppose the vast majority of users will not need the higher resolution, so perhaps have it be a toggle to get the higher-resolution when needed.
If so that's probably like a $3 board in quantity, which could also give you the option to use a USB-C solar panel, which is probably the most versatile and convenient for a lot of people, with LEDs to indicate power and help you aim.
It would go against the low tech concept, but if I was going to build something like this I would probably go for MPPT
The napkin math still doesn't make since if I have to increase the cooling of house ~half the day (would be more since summer has longer days.) Other considerations would be extra wear on the HVAC equipment and just the comfort impact of increased fluctuations.
I know this is “low-tech” but still think it might be possible to fabricate something even if it means spending some of your power budget maintaining the vacuum with a pump.
A big thermos would be much more challenging, though there are already long vacuum bottles/tubes used as solar cookers.