Batteries
Batteries are the starting point of an off grid system. They provide a base for the Battery Inverter to produce 240 volts AC to power the house. They provide all the energy when the solar energy is not present
Batteries can be different chemistry with the main batteries being Lithium but lead acid batteries are still commonly used and very reliable if treated well
Battery Inverter/ Charger
The inverter converts the battery voltage of 24 or 48Volts to 240V AC so that one can use normal household appliances. The charger is used with a generator in prolonged periods of cloudy weather so as to charge the batteries if they get a bit low.
Solar Panels
The panels make electricity from the sun. Panels can be fixed to the roof or be freestanding on the ground. The number of panels required depends on the energy needs of the house. A 2 bedroom house can use more than a 5 bedroom if it has energy inefficient appliances that are left on for long periods
Regulator (DC Coupled system)
The regulator controls the amount of electricity coming from the panels to the batteries. This stops them overcharging. The regulator also typically gives information about the battery voltage and how much daily energy has come in from the panels and is being used by the house.
Solar inverter (AC Coupled system)
With an AC coupled system the solar panels are connected to a Solar Inverter much the same as an on grid system. The Solar Inverter converts DC Solar energy into 240V AC and this is fed into the house. Any excess energy is then used to charge the battery via the Battery Inverter/charger. When the batteries are full, the Battery inverter controls the Solar inverter to allow just the right amount of energy to be provided to keep the batteries at the correct voltage.
Switchboard
The output of the inverter is then wired up as a normal house.
Circuits and Power Points
Most normal appliances can be used. However the total appliances on at any one time should not exceed the rating of the inverter as it may shut down due to overload