Small Off Grid DC/AC System

What it is

AC & DC Victron MPPT example schematic

An Off-grid system is not connected to an external electricity supply and is often in a remote location or is mobile. Small off-grid systems offer an alternative to bringing in mains electricity.

How it works

Solar PV panels &/or a windgenerator charge a battery and the battery supplies power to the loads as needed. All loads are run at the battery voltage (usually 12 or 24 VDC) and special appliances are often needed. Charge controllers limit the charging when the batteries are full. Meters, to monitor system operation, together with fuses to protect wiring are usually included.

To be successful, efficient use of the electricity generated is essential and the system must be sized to meet worst case conditions.

AC & DC Victron MPPT example schematic

Adding an inverter

AC & DC Victron MPPT schematic inc inverter

Adding an inverter is a simple way to increase the system's potential providing you with the ability to use a wide range of appliances that you would use in any normal house. It converts your low voltage DC into 230VAC.

To ensure reliable system operation, the inverter should be carefully matched to the loads so that it is capable of running everything that is needed. Usually a larger PV array, wind generator and battery store will be required than for a DC only system because electrical requirements will be higher.

AC & DC Victron MPPT schematic inc inverter

What it can power

Here are some examples of what you could power:

  • Music systems
  • Fridges
  • Lighting
  • Tools
  • TVs
  • Satellites
  • Telecoms equipment
  • Electric fencing

Essentially you could power anything but if you're regularly using large electrical appliances we recommend you look at the Medium Off-Grid AC System.

What's in the system

As an example here is a list of components in a typical small off grid solar PV system:

  • Solar PV panels
  • Cables & connectors
  • PV combiner box & fuses (often not required)
  • Fuse
  • Charge controller
  • Fuse
  • Battery
  • Fuse
  • Inverter (optional)

What next

We would be happy to speak to you and help recommend a system for you or alternatively you can keep looking through our site.