Off-Grid Solar System Sizing Calculator

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Off-Grid Solar Sizing Made Simple

How to Use Our Off-Grid Solar Calculator

  1. Pop in your postcode
  2. Tell us how many people live at your place
  3. That’s it — too easy.

We’ll show you which of our systems is likely the best fit. If you’re running big power-hungry appliances or tend to use more energy, we recommend the Maxi system.

Heads up — this is a simple tool, based on Aussie averages. It’s a great starting point, but for a tailored solution and proper quote, give us a call.

Traditional Solar Sizing vs the 100UP Way

Designing an off-grid system can get pretty technical. But most families don’t need a full-blown spreadsheet of every kettle, fridge, and light bulb. At 100UP, we believe in keeping it straightforward, especially for rural and off-grid homes where simplicity matters.

The Traditional Way (For the Engineers)

Here’s what a full system design used to involve:

  • Energy Audit – Listing every appliance, power rating, usage hours
  • Solar Sizing – Factoring in your sun hours, especially in winter
  • Battery Bank – Sizing storage for days of cloudy weather
  • Inverter Capacity – Handling peak power loads and surges
  • Efficiency Losses – Accounting for wiring, inverter losses, and real-world use

It’s thorough — but not quick. Great for those who love detail, but not always needed.

The 100UP Way (Practical & Proven)

We’ve simplified the process for the average Aussie household. Based on what we see day-in, day-out, this method works well:

  • Energy Use: 5 kWh per person, per day
  • Solar Panels: 2.5 kW per person (ensures winter coverage)
  • Battery Storage: 5 kWh per person (covers overnight and cloudy days)
  • Inverter: 12 kW system — more than enough for most families

Example:

For a family of four:

  • 10 kW of solar (4 x 2.5 kW)
  • 20 kWh battery bank (4 x 5 kWh)
  • 12 kW inverter

This setup gives solid performance with room to grow.

Smarter Design = Better Value

We follow clean energy guidelines, but we also use our heads. Batteries are the most expensive part of an off-grid system — so we build in more solar up front, and keep the battery bank lean. That means lower costs now, and easy battery upgrades later if you need them.

What You Get:

  • Lower up-front costs
  • Better rebate potential
  • Easier upgrades down the track

Want to talk through your options?
We’re happy to chat. Call us direct on 1300 489 152 or shoot a text to 0400 092 621 — real advice from real off-grid solar installers.