Designing an off-grid solar power system isn’t about guesswork or averages. It’s about getting it right from day one. At Stand-Alone Power Systems, we help rural Queenslanders build off-grid systems that match their real energy needs.
Your Daily Energy Consumption (kWh/day)
Before anything else, we need to understand how much electricity your property uses each day. This is measured in kilowatt-hours (kWh) and forms the basis for your entire off-grid system design.
Common off-grid energy loads on rural properties include
- Multiple fridges and freezers (often 2–3 in rural homes)
- Pressure pumps and irrigation systems
- Washing machine, electric hot water (if used)
- Lighting, fans, TVs, and small appliances
- Power tools, welders, or workshop equipment
- EV charging (now increasingly common)
Typical daily usage for full-time off-grid homes in Queensland
- 15–30 kWh per day for standard homes or small farms
- 40+ kWh per day for larger homes, farms, or properties with machinery or high demand loads
We’ll work with you to build a detailed load profile based on your appliances, lifestyle, and future plans so you get a system that performs year-round, not just on sunny days.
Battery Storage Capacity (kWh Usable)
In any off-grid solar system, your batteries are your fuel tank, and we size them accordingly.
We recommend a minimum of 3 to 3.5 days of battery autonomy, meaning days of stored energy with no solar input. This ensures
- Reliable power during long, cloudy periods
- Reduced generator reliance
- Healthier batteries with longer life by avoiding deep discharge
Battery sizing
- 25 to 50+ kWh usable for most full-time rural homes
- Expandable lithium-iron phosphate (LiFePO4) batteries for flexibility
- We typically install Pylontech lithium batteries, trusted, low-maintenance, and ideal for Australian off-grid conditions
💡 Pro tip Don’t undersize storage and try to make up the rest with a generator. That approach costs more in the long run in fuel, noise, time, and stress.
Solar Panel Array Size (kW)
Your solar array must
- Cover your daytime loads
- Recharge your battery bank by late afternoon
- Provide surplus energy during winter or during overcast periods
For off-grid homes and properties in Queensland, we generally recommend
- 10 to 25 kW of high-efficiency solar panels depending on usage
- Multiple array orientations (NE, NW, or W) for extended solar harvesting
- Ground-mount or shed-roof options for flexibility
We use Tier-1 panels like Jinko and Trina, which are independently verified for
- High energy yield
- Long-term reliability
- Excellent performance in high-heat regions
Inverter/Charger Sizing (kVA/kW)
Your inverter must be able to
- Supply your peak power demand, everything running at once
- Handle surge loads like pumps, compressors, and appliances
- Seamlessly integrate with your batteries and optional generator
We specify inverters based on real usage, not just system size.
We recommend
- Victron Energy for robust, modular off-grid systems
- Selectronic SP PRO (Australian made) for critical loads, larger homes, or hybrid setups
Every system includes a full monitoring interface, and we offer optional remote access so you can monitor performance from anywhere.
🔄 What About Backup Generators
We always design your system so you don’t need to rely on a generator, but we do recommend having one for true off-grid resilience.
Our systems
- Support auto-start diesel generators
- Are built to run independently for weeks at a time
- Minimise generator runtime through proper sizing and design
If you’re already spending over $5,000 per year on fuel and servicing, upgrading your battery bank could be a smarter move.
Planning for Future Loads
Your property may grow, and your system should grow with it. That’s why every off-grid system we design is
- Expandable with modular batteries
- Built with extra inverter and solar capacity in mind
- Sized to accommodate future EVs, sheds, pumps, or granny flats
You only build an off-grid system once, so it needs to be right and ready for change.
Designed for Queensland Conditions
From hot western summers to misty hinterland winters, our systems are built for
- High performance in harsh climates
- Minimal maintenance
- Efficient solar harvesting year-round
- Remote operation with or without internet access
And because we live and work here in Queensland, we design systems that actually suit local weather, terrain, and usage patterns, not just what looks good on paper.
Let’s Size Your Off-Grid System Properly
We don’t sell kits. We don’t guess. We don’t oversell.
What we do is build off-grid systems that are
- Custom-designed for your daily energy use
- Sized for long battery life and minimal generator use
- Built with future expansion in mind
- Installed with local knowledge and proven components
📞 Ready to Get Started
Contact Mark Wright at Stand-Alone Power Systems to get started on a proper system design based on your property, lifestyle, and long-term goals.
📱 0428 678 513
📧 mark@standalonepower.com.au