Off-Grid Solar Systems

In addition to installing grid-tied domestic and commercial solar systems , Deionno Electrical also specialises in off-grid solar systems for homes and businesses with limited or no access to mains power. Our off-grid solar solutions are exclusively designed to suit the specific energy needs of our clients, providing them with an efficient source of remote electricity with complete energy independence, regardless of location.

Whether you want to disconnect from the grid to combat the rising energy costs in Adelaide, or you’re looking for an off-grid solar setup to cater to the major energy requirements of your rural property, we’ve got you covered.

We design and install full off-grid solar across the Sunshine Coast hinterland: Maleny, Mapleton, Conondale, Kenilworth, Eumundi, Cooran and the wider region. Every system is engineered to your site, your loads, and your generator backup plan, with one accountable team from first site visit to year-15 service.

Is off-grid right for you?

Off-grid usually beats grid-connect on these properties:

• Hinterland blocks where the network (Energex on the Sunshine Coast, SA Power Networks in Adelaide) has quoted $30,000 or more to bring power in
• Acreage and rural properties at the end of long, fault-prone overhead feeders
• New builds on raw land where grid connection adds 6+ months to your build timeline
• Existing on-grid hinterland homes wanting energy independence from rising tariffs and frequent outages
• Commercial sites (farms, B&Bs, aquaculture, hinterland workshops) where outage cost exceeds system cost in under 5 years

When off-grid beats grid-connect on cost and reliability

Hinterland connection quotes from Energex, and their SA Power Networks equivalents in the Adelaide Hills, have crept from $25k to $40k a decade ago to $40k to $80k+ today. Once a connection quote crosses about $30k, off-grid is usually the cheaper 20-year option, and increasingly the faster option, because off-grid installs run weeks where grid extensions can run months. Sunshine Coast irradiance averages 5.0 to 5.4 peak sun hours per day across the year, according to Bureau of Meteorology climate data for Caloundra, Maroochydore and Nambour. That puts hinterland yields well within range of a properly sized off-grid system, even accounting for the orographic cloud that builds over the ranges.

Beyond the up-front comparison, off-grid removes the variable cost line entirely. No quarterly bill, no tariff exposure, no “unscheduled outage” calls during summer storms.

There’s a resilience dividend too. When a multi-day storm takes out a hinterland feeder, the kind of outage Maleny, Conondale and Kenilworth see most summers, an off-grid home just keeps running. No grid to lose, no waiting days for network crews to reach a downed line at the end of a long rural run.

Across Adelaide and the Sunshine Coast, going off-grid comes with these benefits:

• Avoid unexpected power outages
• Significant reduction in energy costs
• A reliable source of power for rural areas
• Sustainable and eco-friendly
• High return on investment

How off-grid solar power systems work

Stand-alone off-grid solar systems are typically installed in remote locations to meet the energy needs of properties with no access to the power network. These solar panels can be ground- or roof-mounted depending on the available space and the system size.

• During the day, solar panels utilise solar energy to generate electricity in the form of direct current.
• Solar inverters convert the DC electricity into alternating current which can be used to power the appliances.
• Excess power is stored in solar batteries in the form of DC electricity.
• At night or when the weather is cloudy, the power stored in the solar battery supplies power to the electronic appliances.
• Unlike a grid-tied solar system, an off-grid solar system relies solely on solar batteries for power supply during the nighttime.
• Properties with high energy demands often have a backup power source for when the stored solar power is utilised to its maximum capacity.

1. Solar array

Sized to generate your daily kWh plus enough surplus to recharge your battery from a depleted state across one and a half winter days. On the Sunshine Coast hinterland that’s 2.5-3.5× the size of a comparable grid-connect array: you’re paying for redundancy, not just energy.

2. Battery storage

Sized to carry one to two full days of household load with no solar contribution. The right chemistry is LFP (lithium iron phosphate) for safety, cycle life and thermal stability. We do not install lead-acid batteries on new off-grid builds. The maths don’t support it anymore.

3. Hybrid inverter

DC-coupled hybrid is non-negotiable on off-grid. AC-coupled architectures typically lose 5-10% more round-trip efficiency than equivalent DC-coupled hybrids, which on an off-grid system means a bigger solar array, a bigger battery, and more generator hours. We install Sigenergy, Sungrow, Tesla and GoodWe hybrid inverters, all DC-coupled.

4. Generator (with auto-start)

The generator is your insurance policy for winter cloud weeks, not your primary supply. Properly sized off-grid systems run the generator 30-60 hours per year on average. The generator auto-starts when battery state of charge hits a configurable threshold (typically 30%), charges the battery to a higher set point (typically 80%), then shuts down. You won’t notice it ran unless you check the app.

Why we only install DC-coupled hybrid on off-grid

Off-grid systems amplify every efficiency loss. A 10% round-trip efficiency penalty on a grid-connect system means slightly less feed-in. On an off-grid system it means a 10% bigger battery, 10% more solar, and noticeably more generator hours, because the gap shows up at exactly the moments when sun is scarce. ARENA’s energy storage research confirms DC-coupled hybrid is the dominant architecture in new Australian off-grid deployments for exactly this reason.

Practically: solar panels feed DC current directly into a single hybrid inverter that charges the battery on the DC side. One inversion at most, 92-96% round-trip efficiency, single warranty, native off-grid mode.

Sizing for the Sunshine Coast hinterland

A 6 kW array sized for a Caloundra rooftop will not work on a Maleny ridge: elevation, orographic cloud, dew burn-off and afternoon thunderstorms all change the yield curve. Below are two illustrative sizings for the same household at different hinterland locations.

Example A: Caloundra-edge acreage (coastal hinterland)

Family of 4, 25 kWh/day usage, slight afternoon shade from gum line, typical coastal sun/cloud mix, generator location on south side. Design: 12 kW solar, 30 kWh LFP battery, 8 kVA diesel generator with auto-start. Modelled generator run: ~35 hours/year. Indicative install: $52,000 to $58,000.

Example B: Maleny ridge (full hinterland)

Same family, same 25 kWh/day usage, but Maleny’s morning cloud, winter fog and afternoon storms reduce effective sun hours by ~20%. Design: 16 kW solar, 40 kWh LFP battery, 13 kVA diesel generator with auto-start. Modelled generator run: ~55 hours/year. Indicative install: $68,000 to $76,000.

Same family, same loads: the hinterland tax is about $15,000 of extra hardware. We model your specific site’s yield in PVsyst using BoM data before quoting.

What’s included with every Deionno off-grid system

• Engineered design pack: load profile, generation model (PVsyst-validated), single-line diagram, mounting calcs
• Site-specific sizing for hinterland conditions, not a generic kW figure
• DC-coupled hybrid architecture (Sigenergy, Sungrow, Tesla or GoodWe: brand chosen to suit the design)
• Generator: brand selection, sizing, fuel system, concrete pad, auto-start integration
• Surge and lightning protection on DC and AC sides (mandatory on hinterland sites)
• Region B wind-loading certified mounting (we calculate per site)
• Written compliance pack: AS/NZS 5033 (PV arrays), AS/NZS 4509 (stand-alone power systems), AS/NZS 3000 (Wiring Rules), AS/NZS 5139 (battery safety) certificates and electrical safety declaration
• Single point of contact for warranty, service and any future upgrade

The batteries we install

All three are DC-coupled hybrid systems. We do not install AC-coupled bolt-on batteries on off-grid builds.

Sigenergy: our default off-grid pick

Modular HV stack from 8 kWh to over 48 kWh per phase, AI-driven dispatch optimised for off-grid weather forecasting, and sub-10 ms backup transfer. Sigenergy also offers a 25 kW bi-directional DC EV charger that integrates on the same DC bus as the battery and inverter: no extra conversion losses. For any off-grid build with EV plans or expandable load growth, Sigenergy is the strongest platform on the market.

Sungrow SBR HV with SH-RT hybrid

Proven workhorse, particularly strong on three-phase off-grid for larger homes or rural businesses with workshop loads. Battery modules stack from 9.6 kWh to 25.6 kWh per stack, hybrid inverter rated up to 25 kW per unit.

Tesla Powerwall 3

Excellent product for off-grid sites that want a single-product solution in 13.5 kWh increments. Clean app, simple form factor, fast install. Not modular below 13.5 kWh, which makes it less efficient as the smallest off-grid building block.

Generator integration: the most underestimated component

Most off-grid system failures we get called to fix are generator integration problems, not solar or battery faults. Common issues: undersized generator that won’t hold inverter charge load, fuel tank too small for winter, no auto-start, manual transfer switch that’s never been tested, generator located where the noise drives neighbours mad.

• Sizing: generator kVA = 1.5× your battery charge rate, plus household critical loads
• Fuel: diesel is standard for hinterland (longer storage life, lower fire risk); LPG for some setups
• Auto-start: configurable threshold (typically 30% SoC trigger, 80% SoC stop), full integration with hybrid inverter
• Location: south-side concrete pad, 5 m+ from habitable rooms, weather enclosure, vibration mount
• Service: annual oil change, filter replacement, fuel polish if needed, included in our service plans

Indicative system pricing

Real numbers based on Sunshine Coast hinterland installs we’ve completed. Final price depends on access, switchboard, mounting type and generator selection.

Every quote is fixed-price after site visit: no day-of-install surprises, no “discovered work” change orders.

The 20-year ownership picture

Off-grid is a long-cycle decision. Below is what you should plan for across two decades.

Compare those numbers to grid-connect at hinterland rates: 20 years of bills at $4,000 to $7,500/yr (with tariff inflation) lands at $80k to $150k of cash out the door, plus the up-front grid connection of $40k to $80k. Off-grid wins on lifetime cost for most hinterland properties, by a wider margin every year tariffs rise.

From first call to switched on

1. Free phone consult: we ask about your block, loads, current power situation, and timeline.
2. Free hinterland site visit: we walk the block, measure roofs and ground, look at switchboard or new-build plans, talk through generator location.
3. Engineered proposal: sized system, brand-by-brand options, fixed-price quote, 20-year ownership model, finance options.
4. Design sign-off and order: typically 2 weeks for equipment lead time on the Sunshine Coast.
5. Installation: 3 to 7 days on site depending on size. We don’t leave your home without power overnight.
6. Commissioning and handover: full system test, app set-up, written documentation pack, walk-through with you.

Why choose Deionno for off-grid solar in Adelaide and on the Sunshine Coast

Are you planning to invest in an off-grid home or commercial solar system in Adelaide?

Poorly-designed off-grid systems may lead to compromised efficiency, frequent breakdowns, costly repairs, and a significantly shorter equipment life span.

At Deionno Electrical, we have designed and installed countless off-grid battery systems for properties around the Adelaide Hills and Flinders Ranges in South Australia. Our qualified solar technicians take time to understand your property’s electricity requirements, available space, and budget before suggesting the most suitable off-grid solar system to help you achieve optimal performance and results.

We are Adelaide’s trusted solar installers with a solid customer base, known for exceeding clients’ expectations through complete after-sales support, service warranties, and regular solar maintenance for all off-grid solar systems.

With years of hands-on experience in solar technology, Deionno Electrical aims to deliver exceptional service through expert designs and quality components, making sure you get the best value for your money. Call 1800 610 165.

Engineered off-grid systems for hinterland properties: designed, installed and serviced by a SAA-accredited local team.

• SAA-accredited installers (Solar Accreditation Australia replaced CEC installer accreditation in February 2024). All our installers hold SAA Stand-alone Power Systems (SPS) accreditation, the specific endorsement required for off-grid design and install.
• Local electrical contractor: not a national one-day-install reseller. We live and work on the Sunshine Coast.
• Engineering-led design: every system modelled in PVsyst against your site’s actual irradiance and load profile, not a postcode average.
• Brand-agnostic recommendations: Sigenergy, Sungrow, Tesla, GoodWe. We tell you which one suits the install, not which one we get a kickback on.
• New Energy Tech Consumer Code signatory (NETCC), the consumer-protection framework that replaced the older Solar Retailer Code.
• We service every system we install: same local team for installs, warranty work and ongoing maintenance.

Sunshine Coast hinterland areas we serve

Maleny, Mapleton, Montville, Flaxton, Conondale, Kenilworth, Eumundi, Cooran, Pomona, Cooroy, Black Mountain, Belli Park, Verrierdale, Doonan, Eerwah Vale, Yandina Creek, Bald Knob, Witta, Reesville, Bli Bli rural, and surrounding rural blocks. Off-grid builds further afield across South-East Queensland on request.

Ready to talk?

Send us your block address and a recent power bill (or your network connection quote). We’ll come out, measure up, and quote a fixed-price engineered system. No deposit required for the site visit.

Call us on 1800 610 165 or fill in the contact form below.