Mount Rumney Escapes

Expert Electrical Tasmania (EET) was selected by Mount Rumney Escapes as their Engineering, Procurement and Construction (EPC) contractor for an Off grid Eco village near Hobart. 

The brief was to provide the accomcodation with a modular, modern, efficient, reliable & renewable power source.

Mount Rumney

Job type: off-grid, commercial


  • The project was a greenfield project which allowed EET’s technical representative to have an input into many of the design considerations to allow for the system size to be as efficient as possible.
  • EET’s partnerships with SMA & Solarwatt enabled our offgrid specialist to design the perfect system.
  • mulitple roof faces allowed for the distribution of energy production across all hours of the day (North-West & East facing panels = all day power rather than a large peak at midday)


  • The 5 accomodation houses have a large geographical footprint, which means a large distance for the energy to travel.
  • Accomodation has an inherent difficulty in timing the distribution of energy usage. (It is ver y difficult to tell clients when to turn things on/off
  • Large power consumption
  • The system was to be installed across multiple structures


  • SMA systems are all AC Coupled – This allowed us to distribute the energy across all 6 buildings without major losses.
  • Using a combined single and 3 phase system leads to redundancies that if any one inverter failed the system could easily keep running. whilst also being able to be installed across six buildings
  • utiltising 3 phases at each property meant that we could distribute the load to any inverter we needed (this allowed for future proofing and load distribuition)
  • designing input on the properties to allow distribution of the power consumption to appropriate times.
  • The system was to be installed across multiple building structures and all linked together via a technological hub. (this is a massive strength of the SMA equipment)

System Installed:

24.885kw of roof mounted Solarwatt solar panels across four accomodation buildings (79 x 315w panels) Solarwatt panels are of double glass construction and are manufactured in Dresden, Germany. They come with a 30 year warranty.

20kw of SMA solar inverters. distributed across four accomodation buildings. 3 x single phase inverters and one 3 phase inverter.

24kw of Offgrid inverter Capacity – 3 x SMA sunny island 8.0 linking in 3 phases giving a total capacity of 36kw of peak draw.

46.2 KWh of Lithium battery storage.

10kwh of Backup generator capcity.