Offgrid living

We have a small flight case on wheels that we use as an outside kitchen with the following appliances:

• 1 induction hob - 1.9KW max
• 1 rice cooker - 400W, which also works as a slow cooker
• 1 small oven / grill - 800w
• 1 "travel" kettle (0.5l) - 900w

They are all plugged into a 2500W low-frequency inverter which is connected to a 48V 5KwH LiFePO4 battery, and is serviced by 3 PV systems, two 800w and 1 360w in various position.

I would recommend not using 12 or 24v for cooking, as your cables will have to be really short and thick.

We can use all the appliances at once on the inverter (athough the inverter is rated for 3kw over 4 minutes max which helps) without problems.

Last year, we cooked on it every day for around 2 weeks when the weather was good (and I was working from the garden), and it was very reliable.

All those ratings are max, and the induction hob worked really well, and pulsed from 900w to 1.7kw during cooking pasta sauce once it got up to temperature, for example. It was only £35 from some dodgy chinese make, which has an advisory on it from our regulator about fusing problems, but we use it outside and there's various fuses between it and the battery, so we should be ok :/

I really wanted to get DC equipment so I wouldn't need to use an inverter, but finding any is difficult. The best DC kettle I have found is only 1L and 24v with a "din" connector, and I haven't had chance to try and set that up with a DC-DC converter yet. A friend of mine modified a little oven like we have to work off ~42v DC, which worked, but I don't know how he did it :( I did buy a 48v immersion heating element, which I wanted to use to heat water for washing up etc, but I've not tried that yet either :(

There are various DC fridges you can get for camping, but we don't use them on the system .

Hope that helps!

It's just started getting warm and sunny here, so we will start using the system again when I am working outside. We have only used it once this year so far.

There's also plasma hobs coming out from China, which look interesting, and might behave more like cooking on gas. I would like to try one sometime, but they aren't very common yet.

I have a 5 kW continuous (10 kW peak) square wave inverter and a 10 kWh battery bank.

• 2000 W kettle - runs fine
• 2000 W ceramic / infrared cooktop - runs fine
• 900 W microwave - runs fine

I've got a couple of induction stove tops. They mostly use 2kw max, but pulse on and off to emulate lower power levels. So if you can't supply 2kw, you'll not have a good time.

I have run one on a 2kW inverter and an AGM battery.

https://www.ikea.com/au/en/p/tillreda-portable-induction-hob-1-zone-white-40493509/

They are dirt cheap, so not a huge risk if it doesn't work.

There isn’t a heat pump oven (yet) so the biggest improvement to electric cooking efficiency has been those portable induction cooktops. They are all rated at around 2000w.

I would still keep a small propane or multi fuel burner just in case.

I can't look at the exact usage details day to day (and I'm not offgrid) but my electric stove, a Copper stove, has a 5 kWh battery in it and their marketing claims you can cook 3-5 meals during a power outage. Hopefully that's a useful data point

Cooking is really high draw for a relatively short time. Fry some eggs - 600-800w for about 5-7 min. Bake a cake - 3500w for 10 min to preheat, then the oven cycles on and off for 30 min or so.

It’s possible, but you’ll need a good sized solar array, and a battery bank and inverter that can provide the juice. Another challenge is having enough power for everything else and cooking off season - unless you’re close to the equator. It’s not hard to get an appropriately sized inverter, and lithium handles the draw pretty easily especially in a decently sized bank. 25 years ago I had friends who were fully off grid using electric, but it was supported by a proper windmill; 5kw if I remember. Even in mild breeze the 500watts all day and night helps; when it got windy there was a real concern about boiling the batteries.

It takes a lot of power cook food. Even if you are using a microwave or induction burner. Just start looking at the power consumption figures of microwaves. they start at 1000 watts.

Maybe consider a tiny marine wood stove instead.
https://www.practical-sailor.com/belowdecks-amenities/galley/navigator-wood-stoves-provide-classic-heating-and-cooking-onboard/

Back in the day, my grand parents cooked with a wood stove that also heated the house.

In the summer they would put two poles under the stove and carry it out to the back porch to use it in the summer kitchen on the back porch.

Also depending on your living situation. there is also the rocket stove.

https://fireandsaw.com/what-is-a-rocket-stove/

There also are the more traditional wood stoves that my grand parents used they are still made today.
https://www.lehmans.com/category/ranges

Edit: There are also masonry cook stoves.
https://insteading.com/blog/masonry-cook-stoves/

My wife cooked lunch today. Beef stew and toasted bread. The stew in a pressure cooker, vegetables and bread in a air fryer. Some of that was the kettle boiling too. We don’t use a conventional stove for anything. The regular bumps through the night is the fridge/freezer, it runs on solar permanently.

Green in incoming PV from 6 panels. 5kW inverter. Yellow is power draw. Just don’t start two appliances that both draw more than 2kW at the same time, and you’re good.

Once one gets the right cookware (mostly cast iron) the main disadvantage of induction cooktops is the fan noise, for me. I use one on a daily basis. Additionally I have an instapot pressure cooker, which is super handy. I also use an electric water boiler. And it all runs off the solar panels on the roof. It's awesome!

I have a 1 element induction cooktop with a 2000 W rating, so roughly 2 kWh at max setting, but I think it is really fast as it doesn't waste energy heating the air around it. Breakfast would take 10min to set up on propane, but now if I doze off, I might burn my food

edit: If you want, you could also build your own solar stove if it makes sense in your region