The system size can vary from very small bach systems to very large full family systems depending on the individual needs of the occupants. However most families fall into the category of what we call "large bach / small house “ type of system. Bach or caravan systems are those that have basic needs for lighting and a few other small electrical requirements. Over the years these systems can tend to be added onto and eventually grow to need an inverter for a vacuum, microwave, washing machine, refrigeration or other 230v ac appliances.
The first thing we advise families for independent off-grid housing is to make their own arrangements for 3 essential services which are cooking, heating and hot water. Although we can provide for those items it becomes a very expensive proposition, so most customers gladly cater for those three things with other technologies than electricity.
The second item is for people to complete a Load Analysis sheet in which they list every item that will be used in the house; this will then determine the battery size which is the heart of the system. The design then provides enough photovoltaics, wind or hydro to charge the battery bank. The last major component is the inverter/charger which provides the required 230v ac for the loads and facilitates correct battery charging via a back-up generator, if used.
It is also advisable for customers to consider how they will dispose of their greywater and wastewater. Although this is outside the scope of our company, customers need to consider how they can provide for these essentials. Avoid systems that are high energy users such as aerated wastewater treatment plants as they are unsuitable for most off-grid systems.
On the other hand, potable water needs and water pumping (domestic, garden and stock water) are essential items that we can help with provided it does not require large scale irrigation pumping. Water pumping is usually achieved directly with solar water pumps and panels.
The groups of people that live off-grid are usually the ones that are more forward thinking in terms of sustainability. By necessity they quickly come to grips with energy efficiency, phantom loads, and wise use of energy. We have a large amount of helpful background information available that we can post out to those considering living off-grid which is about the concept, is non-technical in nature and will help enable you to understand what is involved.