System Size

What Affects Your Solar Setup

How Many Solar Panels Does Your Kiwi Home Really Need?

Wondering how many panels to slap on your roof? It’s not exactly a one-size-fits-all situation. Here’s how to figure out what’s right for your place without overcomplicating things.

What You’ll Need for a Solar Setup

What Affects Your Solar Setup

Before you start counting panels, there are a few Kiwi realities to consider:

Your power habits – Take a squiz at your last few power bills. How many kilowatt-hours are you chewing through each month? This gives you your starting point.

Your roof situation – In NZ, north-facing is the sweet spot (unlike our northern hemisphere mates who want south-facing). But don’t stress if your roof faces east or west – you’ll still generate decent power, just at different times of day.

Where in Aotearoa you call home – The Far North gets heaps more sunshine hours than Invercargill. A 5kW system in Auckland might generate 7,500kWh annually, while the same setup in Dunedin might only manage 6,000kWh.

What you want from your system – Just trying to knock the edge off your power bill? Or dreaming of energy independence with batteries and telling your power company to jog on?

Rough Guide to Panel Numbers

Most solar panels these days are around 300W-400W each. Here’s what different setups look like for typical Kiwi homes:

Bach, Unit or Power-Savvy Couple (2-3kW)

What you’d get: 6-10 panels spanning about 15-25m² of roof
Annual generation: Roughly 2,500-4,500kWh (about 30-50% of an average household’s usage)
Good for: Singles, couples, small flats, holiday homes, or those really careful with power

Standard Family Home (4-5kW)

What you’d get: 12-16 panels covering 30-40m² of roof
Annual generation: About 5,000-7,500kWh (could cover 60-90% of average household usage)
Good for: Your typical 3-4 person NZ household with the usual appliances

Power-Hungry Household (6-10kW)

What you’d get: 18-32 panels sprawling across 45-80m² of roof
Annual generation: A hefty 8,000-15,000kWh
Good for: Large families, homes with power-guzzlers like spa pools, EV charging, or if you’re running a home business with equipment

Is Bigger Better?

With panel prices dropping like a rock over the last few years, many Kiwis are opting to max out their available roof space. Why?

Winter still exists – Even in the “Winterless North,” your solar generation can halve during June and July. More panels help keep the lights on during those shorter days.
Future-proofing – Planning to get an EV in the next few years? That’s a power-hungry beast that could double your electricity use.
Making it worth your while – There’s a fixed cost for installation regardless of system size, so the cost per panel actually drops as you add more.
The sell-back factor – If your power company offers decent buyback rates (some are definitely better than others), excess generation becomes an asset, not a waste.

Practical Stuff to Think About

How much usable roof have you got? – After you eliminate shaded spots, chimneys, skylights, and awkward angles, your perfect 30-panel dream might need to slim down.
Budget reality – More panels mean more upfront costs. Though the price per panel drops, your bank account still feels the pinch.
Local network limits – Some areas (looking at you, parts of Wellington and rural networks) have restrictions on how much solar you can feed back to the grid.
Consent issues – Most residential installs don’t need council consent, but if you’re pushing the boundaries with a massive system, you might hit some red tape.

The bottom line? For most Kiwi homes, a 4-6kW system hits the sweet spot between cost and benefit. But everyone’s situation is different – and that’s why getting a proper assessment from someone who knows their stuff is worth every penny.

The best first step?

Get a proper assessment of your home. Every property is different, and a professional can tell you exactly what kind of setup would work best for your situation.