OFF GRID SOLAR SYSTEM


Supplying my off grid house with power has been an interesting and complex exercise. Solar was the obvious choice for me given the complete lack of trees on my block!  Although I studied Industrial Design at uni, my working technical knowledge is limited to all things furniture – and the fabrics, finishes and raw materials that go into them.  I am sure that someone with more electrical knowledge and/or a willingness to manage a simpler system could supply their solar needs for less than what I paid.  But then I get my furniture & fixtures for next to nothing so I think we are even! 

SAE Group was the solar company I decided to go with and they quoted me on their usual lithium battery – the Chinese made Pylontech US2000B.  This came in at about $29,000.  Not knowing much about batteries I set about researching the various options on the market.  I came across this website which had some great comparisons and general info and as a result, I honed in on the Simpliphi range.  In particular, I was surprised by the difference between the capacities after 10 & 15 years.  At the 10 year mark, the Pylontech was at 72% capacity (70% or less being the point at which the battery is likely to be unusable) whereas the Simpliphi was still well above 72% after 15 years.   

I asked my solar guys to quote and provide a comparison on the Simpliphi range.  It came in at about $9,000 more but had an expected life of 27.4 years.   Making the cost per kWh over its lifetime only $0.59 compared to $0.95 for the Pylontech.  Of course, it really depends on how long the batteries actually last for!  Simpliphi batteries are warranted for 10 years, so if something goes wrong at say 15 years then the increased cost has been just more money for nothing!  As with any product, the lifetime of the item versus the increased cost is a gamble the consumer has to make.  So I took the chance and here is the system I ended up going with and some images of the installation …

Off grid solar system image 1

THE KEY SPECS

  • 6.5kW system
  • Fronius Primo 5.0kw 1PH Int. Including WiFi inverter
  • Victron Quattro 48/8000/110 – 6500w 48V Inverter/charger
  • Victron SmartSolar 150V 35A MPPT
  • 14kWh Simpliphi (4 x 3.5kWh) 48V Lithium ferrous phosphate deep cycle battery bank
  • 20 x 315W Sunpower solar panels
  • 20 x S/S racking
  • Shelf for each battery
  • Bollard (a requirement due to being inside a garage)
  • Includes AC wiring to sub-board, battery bank connectors, DC wiring, off grid inverter wiring
  • Includes Victron motoring system, full inverter integration & cloud-based monitoring  
  • Includes installation & commissioning 
Off grid solar system image 2

AND THE FINAL PRICE?

After 104 STCs (Small-scale technology certificates) the final price came in at –

$38,504 inc GST (April 2019)

The installation was completed in 2 days and I was provided with training on the system shut down and the cloud-based monitoring ap.  I don’t have anything connected to the system yet as the house fit-out is ongoing but I did test a kettle and a heater on the supplied double GPO.  Once the house is complete and all my appliances hooked up, I will post some more info and screenshots of the power usage.  Subscribe to my newsletter so you don’t miss my updates!

If you would like to read more about the Simpliphi range I found this website really informative and also very funny!

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