Living Offgrid means you need to adjust to nature and the natural cycle. This may take a bit getting used to but is definitely worth it. There is 2 limiting factors on how much power you can take from your system.
Inverter maximum power output
Power is generated using whats called an inverter. It converts your battery-and system-voltage and provides a standard 110/220 volt for your household appliances. Inverters come with a maximum power output, although they usually have a few split seconds of overcharge capacity. This is a hard limit. In fact you should stay well below your maximum Inverter capacity when picking electric devices. A reasonable inverter capacity is around 2,4kw – 6 kw.
Battery storage capacity – incoming energy
Your battery will only carry you so far. See your battery as storage to carry you over the night or two on normal conditions, or over a few 5-6 stormy and cloudy days running on limited mode. Use high power devices when you have the sun blasting your panels and not when you need to get the energy from your batteries. It may sound simple, but it will definitely take adjusting when you are not used that lifestyle. When you expect a period of bad weather with low power production, adjust accordingly. Consider using a broom instead of a hoover, and preserve battery capacity. Depending on your location a wind turbine can help to keep power production up during bad weather phases.
Advice for electric Devices
Rule of thumb, always go for a power efficient model if available.
The best to use is laptops. They are already optimised for low power consumption. Typically they come with their own battery, this will help to stretch your resources a bit further.
And yes there is decent gaming laptops, stop gasping for air..
Washing machine, Dishwasher
The main issue here arises from the machine wanting to heat the water. This will use some 2kw power on normal machines. That is a rather harsh load to have available during bad weather. There is plenty of nice models on the market with the option to wash “cold”. Doesn’t meant you need to actually wash cold, it just means the machine is not in control of the temperature. Assuming you are using other methods to produce warm water, simply hook the input of your washing machine on a standard valve that offers temperature control. Adjust the Temperature manually according to your needs.
It is highly recommended to take a very power efficient model.
Place your fridge or freezer in a cold room like a basement. The less it needs to cool down the less power it will consume, simple math. To further increase efficiency it is possible to add more isolation by simply fixing 10cm polystyrene plates all around.
As these devices usually run 24/7 they can be a rather intense permaload. It is possible to use a timer and cut power to the freezer for a few hours over the night, this can help significantly with power management. Also, don’t have to much empty space, fill it with plastic bottles full of water to have a “thermal mass battery” that can easily keep your stuff cold for few hours of no power.
Cooking, Stoves, Microwave, Toaster
Running these on electricity is generally a bad idea in most offgrid setups. These devices consume a lot of power, ranging from 2kw to 4kw. If you wanna make some food in the night or during bad weather phase your battery is not gonna be very happy. For cooking, gas (butan, oktan, biogas, etc.) is a good solution. You will find a wide variety of products to run on gas from camping up to chef level. A “standard” 10kg bottle of gas will be enough to cook half a year up to a year. Installation is rather simple. Using gas from the bottle generally reduces the risk of gas explosions compared to gas from the “line”, as the amount provided is usually not enough to cause any bigger explosions.
Heating in winter using electricity is very unlikely to be efficient, unless you have very stable power production from wind turbines. However, cooling in summer is a thing. As most solar systems should be optimised for the bad times you will have a lot of surpluss power during the summer month. Using this for air conditioning is legit use. Scale your air conditioning according to your power production.
More information on this can be found in the Clima control section.
Power tools, Hoover
The less power they consume the better.
Don’t go cheap, most cheap models will consume a lot more then higher priced ones. Inform yourself properly what is available on the market. Prefer battery powered ones where available, it sucks when your power is out and you are not be able to use any tools, also it helps to stretch your resources of the main battery.
In short words, a normal one NO. These bastards take 2- 3kw of power and will suck the live out of your battery rather quick. Highly recommend getting a small low power one. They can be found at around 300 Watts combined with a towel it will take a minute longer but get the job done.
Most pump variants are available for low power consumption.
Price ranges can be rather big, Ex. a normal heat-circulation pump will cost around 15€ and consume 60watts, a low power model will only consume 12 watts but drain you 120€ ‘ish. Rule of thumb, the more a pump runs permanently the more it makes sense to invest into a low power model.
Use LED lights to reduce power needs. Do not go with old conventional bulbs.
Unrecommended, even though they usually run for only 5 mins, they still take around 2kw of power. Best practice is to have a gas powered stove and use a kettle or pot.