Off-Grid Living on K'Gari

Nestled in the hills of Orchid Beach on stunning K’Gari, formerly known as Fraser Island, an unassuming home functions with so much off-grid power that it could be mistaken for city living. Back in 2010, our clients first reached out to us with a unique proposition: crafting a comprehensive off-grid solution, given the infeasibility of accessing grid electricity for their secluded island residence.

Springers Solar director, Joe Springer, and off-grid energy expert, Dave Whinnett, worked closely with the customer in 2010 to determine the home’s electricity needs and formulate a long-term, no-fuss solution.

The two-bedroom home required a reliable source of energy to power lighting, refrigeration, a hot water system, and internet. The homeowner’s priority was to provide enough power to cover their daily consumption requirements without needing to micro-manage their usage. At the time, a 24V off-grid solar and battery system was implemented. Our team employed an arrangement consisting of eight 900Ah Raylite wet cell batteries, configured in series-parallel to yield a total storage capacity of 43kWh. 

At the heart of the setup, a first Generation 2.5kW Selectronic Inverter Charger operated reliably to convert solar energy harnessed from the PV array into a viable power source for the residence. The total usable capacity of this battery system was 8.6kWh per day - 20% of the rated capacity of the total battery setup. To achieve a longer lifespan with wet cells, a low depth of discharge is required to preserve the integrity and performance of the battery. For its time, this DC-Coupled system proved an excellent demonstration of what energy storage systems were capable of achieving. For more than a decade, this home was supported by an excellent off-grid energy solution and hummed along reliably.

Now, 13 years later, the owners of the house reached out to us again and requested a full system upgrade. The wet cell batteries had begun to collapse under the load, as predicted for their amount of use and lifespan. The homeowners were also interested in integrating newer technologies that had since been released to the market to future-proof their home for more decades to come. 

Prioritising an effortlessly managed and virtually maintenance-free setup was again our homeowner’s key goal. With this in mind, we designed a system that maximised solar panel placement on the roof and installed an oversized battery system designed to store surplus energy. This strategic decision empowers the occupants to conveniently expand their electricity consumption within the household, free from concerns about the system’s capacity to accommodate additional demands now and in the future. In short, this system has enough energy to power a city dweller’s lifestyle!

Forty modules of 430W Trina Solar Vertex S+ solar panels were installed to cover the entirety of the northeast facing roof. With a combined capacity of 17.2kW, the array will easily generate power to cover the home’s daily needs and keep the solar batteries charged. Trina Solar’s N-Type Vertex S+ range was selected for its innovative dual-glass structure and resilience against salt and dust corrosion. Given the home is situated on the world’s largest sand island, safeguarding the panels and overall system integrity ranked as a top priority. Benefitting from Trina Solar’s advanced design principles and comprehensive warranties, our customers can rest assured that their system’s performance will remain steadfast for many years to come, even in the harsh environment of which they reside.

Ten 48V 4kWh PowerPlus Eco Lithium Batteries were carefully installed in a sturdy PowerPlus IP54 wall cabinet, complete with thermal temperature control. This arrangement results in a total lithium battery storage of 40kWh. Due to lithium’s ability to maintain integrity at a high depth of discharge, the homeowner can withdraw up to 32kWh daily (80% of total capacity) from the battery bank. This generous reserve ensures autonomous system operation for approximately five days during inclement weather before the generator needs to take over.

A 48V 7.5kW Selectronic Inverter Charger was installed for reliable power conversion and was coupled with a duo of Fronius Primo Inverters, resulting in a combined inverter capacity of 13.2kW. This enhanced setup operates on an AC-Coupled configuration, empowering it to handle substantial AC loads throughout the day, including power-intensive devices like air conditioning and electric vehicle charging.

Both the customer and our dedicated after-sales service team can monitor the system’s performance and metrics thanks to Select.Live, Selectronic’s remote monitoring system. We can view in real-time how the system is functioning and can proactively diagnose faults if they arise. Given the nature of an off-grid system, monitoring the performance of the system is critical to ensure consistent, optimal performance. Remote monitoring provides complete peace of mind as our customers don’t need to worry about whether the system is performing - we’re making sure it is. 

With surplus energy being generated by the system and the homeowners keen to future-proof their property, they chose to incorporate a Level 2 EV Charger into their driveway setup. The Tesla Wall Connector was the preferred choice due to its versatility in accommodating various vehicle types. This inclusion of the EV Charger, powered entirely by solar energy, empowers the residents to lead a fully self-reliant and sustainable lifestyle.

To facilitate backup power in the event of an emergency, our team upgraded the previous generator to a more robust and modern Himoinsa model. This enhanced generator stands ready to provide backup power to the home should the AC supply deplete - the system has been meticulously designed to match requirements, reducing the likelihood of needing the generator except in cases of severe weather conditions. To maintain its condition, the Springers installation team has scheduled routine runs to keep the unit operational and in prime shape.

The system stands as a testament to meticulous design and outstanding workmanship, affording our customers continuous access to solar energy day and night, effectively powering their home akin to a modern city apartment.