Choosing Electrical Appliances
Solar power can be used to power just about any domestic appliance. The only question is; can you afford it? With solar power it certainly pays to select your appliances carefully.
Energy Consumption
The energy consumption of different appliances varies enormously, but there are two basic rules of thumb:
- DC is better than AC
- Heat is always expensive
DC is better than AC
If there's an appliance you want that's available in a 12 Volt DC version then it will use less power than the 220 Volt AC model. Why? Because there is no inverter efficiency to worry about and also it will be designed to be operated from a car battery, which is a limited source of power. You will save money on the inverter as well. All sorts of household appliances are available in 12 or 24 Volt versions for the leisure and 4x4 markets. Try caravan shops and 4x4 shops; you'll be surprised what you can find.
If the system is large, however, it may not be sensible to use a large number of 12 Volt appliances. That is for two reasons; firstly the system voltage is likely to be 24 Volts, and secondly the amount of big low-voltage cabling is likely to be difficult to accommodate. The increased efficiency and lower cost of modern sine-wave inverters has made it possible to economically operate many ordinary household appliances. It's still necessary to carefully consider the power consumption though.
Heat is always expensive
Heating elements use lots of electricity, so try to avoid appliances with heat elements built in. That's things like dishwashers, washing machines, tumble driers, heaters, toasters etc. If you can feed your washing machine hot water from your solar geyser then you will save a huge amount of energy.