So in our final section we’ll run through the electrical side of the system. The hub of the electrical system including the 6kW Sunny Island inverter charger, SMA Sunny boy 3600W Grid tie inverter, Batteries and switch gear is all contained within a lockable room for safety, the inverters and switch gear are mounted onto fire proof board fixed to a timber structure. It may seem counter intuitive that we have used a ‘Grid tie’ inverter as part of an off grid installation however this prevents the solar array from overcharging the battery bank through the use of frequency shift technology, for this work the grid tie inverter must be set to off grid mode.

As well as  PV panels and a back-up generator, in off-grid situations like these and if the site is suitable it’s always advisable to have a wind turbine to help with the charging of the batteries especially in the winter months. Crashpad Lodges went with a Leading Edge 600w Wind Turbine, the turbine feeds directly to the batteries with any over charge been taken care of using a diversion load controller and dump load. An important part of any micro wind installation is to be able to make the turbine safe in high winds; this one is on a winch system so it can be lowered in storm conditions.