Why pairing more panels with your inverter can deliver better return on investment.

Let’s clear something up right out of the gate: oversizing your solar inverter is not a sin. In fact, it’s smart—especially when in most cases, solar panels don't all face the same direction.       


Now, we get it. You’re wondering: “If my inverter is only 5kW, why am I slapping 6kW of panels on the roof?”

Welcome to the wonderful world of intentional oversizing, and no—it won’t blow anything up. Let’s unpack it.


What Is Oversizing?


Oversizing simply means installing more solar panel capacity (kW) than your inverter’s rated output. So if you’ve got a 5kW inverter and you install 6kW worth of panels, that’s a 20% oversize.


Some folks get nervous about this. “Won’t I be losing out all the time?” Sure - you'll lose out a little bit, but only on the sunniest days, in the sunniest months.

Truth is, unless your panels are all facing the same direction and pitched north at 25 degrees or greater, your panels are unlikely to hit their rated output outside of summer.


And even if you have the perfect roof and all your panels face the same direction—a 20% oversize can cause a few percent of total generation to be “clipped”. But this will only happen on sunny days, and only when the sun is high in the sky. You'll have no problem of clipping before 11am, or after 2pm.


But we’re not living in a lab. Half the time there's cloud cover; and that means your panels produce less. 70% of the time its not 'lunch time'; but instead its 10am, or 4pm, etc...


And nothing going to blow up. Even with a 200% oversize, nothings going to blow up, because solar inverters take what they can and need.  They're not under oath to take those sexy energized electrons.


The electrons that get 'clipped' just take another lap around the solar circuit.


Here’s Why 20% Oversizing Makes Sense


  1. Outside of the sunniest summer days, you need all the panels you can get. 
    Those “shoulder hours” matter. A DC over size means you get more energy in the mornings, afternoons and cloudy days. More energy when you really need it = better ROI.
  2. Inverters operate more efficiently with more DC. 
    If its cloudy, you want as many panels as you get to make sure the inverter runs efficiently. Most inverter spec sheets have a graph showing their efficiency curve.
  3. You have a DC coupled battery
    You won't clip if that clipped energy goes straight into the battery. DC to DC!
  4. Panels are cheap. Larger inverters and monitoring equipment aren’t.
    If we're starting with a 5kW inverter, adding a few extra panels for a nice oversize is far more cost-effective than jumping to the next inverter size, because those larger inverters need complex monitoring equipment to curtail exports to the 5kW-per-hour export limit.
  5. Your panels face different directions.
    Just because you have a 10kW system, doesn't mean you're guaranteed a full 10kW. If your panels are East and West, good luck getting 10kW in the hour outside of November - February, even at mid day.



The Kiwi Context: 6kW Inverter, 7.5kW of Panels = Sweet Spot


New Zealand’s single-phase homes tend to be limited to 5kW per hour of export. Your inverter can’t send more than that back to the grid unless you have more phases to sell energy on.


By pairing up to 7.5kW of panels on a 6kW inverter you:

  • Generate tons of energy
  • Only need your home to draw 1kW during the peak sunshine hours to ensure there isn't any clipping. This is super easy with a hot water cylinder on a timer, or a spa pool or pool pump running during the day.
  • Have tons of energy available for charging a DC coupled battery like Sigenergy, Tesla Powerwall 3, Sungrow, etc.


The large grid tied system: 10kW inverter, up to 12kW of panels and a timer or two


Got an electric Hot Water Cylinder, or a combination of Spa pool and Water pump?

Chances are - even without a battery, you'll do fine with anything up to a 10kW inverter with <12kW of panels.


  • Generate 10kW per hour between 11 and 2 (with a little clipping only on the sunniest days).
  • 3kW per hour goes into your hot water cylinder, or other timed appliances such as a pool pump, septic, etc.
  • If you have a DC coupled battery, the rest goes into the battery
  • 2kW may get clipped without a battery, but again - that's only on the sunniest days, and mostly only in summer.



The Final Word


If your solar installer tells you 25% oversizing is bad—they’re probably stuck in 2015.

And if they tell you a 10kW inverter on single phase is overkill, don't be afraid to ask why.


Ultimately solar is a financial decision, and you should be considering the cost and benefits based on their own merit. 

Most people with LARGE solar systems get very little bills in summer. And those lucky enough to have more phases to sell on often get bills below zero!

As we've said often to our clients - "If your summer bill is $0 instead of -$30, who cares?"


The modern reality is this: panels are cheap, inverters are smart, and clipping is strategic, not catastrophic.


So go ahead. Be a little oversized.


Because when it comes to solar, bigger (within reason) is usually better—especially when you're clever about it.


Want help designing a solar system that pushes the limits but plays within the rules?
We’ll find you a deal that doesn’t just work—it works smart.

Solar subsidies - likely ... to hurt your back pocket and stress levels

By looka_production_130270016 • March 19, 2026
Because supply and demand is the guiding principal behind prices in every market...

Why We Can’t Size Solar Batteries Like The Aussies Do

By looka_production_130270016 • February 7, 2026
Why We Can’t Size Solar Batteries Like The Aussies Do Most kiwis want solar to reduce their power bills, and mostly – their winter power bills. And most Kiwis tell us – “We want a solar system that charges up the batteries during the day so that we can heat our home at night.” News flash: Yeah........... Sorry - that’s not going happen aye. Here’s why. Everything You’ve Heard About Sizing Solar & Batteries Is Probably Wrong (For NZ) When you jump online and search about solar, you’ll find information from Bloggers and YouTubers in parts of the world with entirely different energy demand patterns. Think about Australia for a second. 99% of homes in Aussie use tons of power in summer, which is conveniently when they generate the most solar. Our clients often come to us with the idea that solar + battery means very little grid use with the potential for 'off-grid in the city'. In Aussie, that's almost possible! But not here, because most kiwi homes use more power in winter, than in summer - which is inconveniently when solar systems produce ~50 to ~70% less. We’re left with two conundrums: in summer, you can’t make the most of a big battery… and in winter, you can’t charge one. Batteries Should Be Sized According To Your Spare Winter Solar This is the main point. Read the rest of the blog for more insight. ‘Nuf Said. You Won’t Discharge A ‘Uge Battery In Summer Let’s say your solar system generates ~40kWh per day in summer – (typical for a 20 panels system). But your home uses ~25kWh per day. There’s a 15kWh difference between what your home uses, and what you’re generating. So if you don’t need that spare energy, what’s the point in storing it? * Whether you have a huge battery or not, if your home doesn't use the spare solar, you'll be selling that 15kWh for about 17c per unit, which adds a $2.55 credit to your power bill EVERY day. You Don’t Need Much Storage In Summer If your home uses ~25kWh on a typical summer day, the question is: how much of that energy demand occurs after the sun goes down? ‘Cos the reality is – most homes don’t use much at all. After 8pm in summer: … You’ve done the cooking … Used a bit of aircon in the arvo … Your hot water’s steaming … The beers are cold … And your TV uses 100w So on a 25kWh day, your home might only pull ~10kWh between 8pm & 8am. … So, with these rough summer calcs, with 20 panels, most people can only make the most of a ~10kWh battery. C’mon – Surely It Makes Sense To Have A Big Battery In Winter? Yeah, I know that’s what you’re thinking. Everyone thinks that. You get home from work... Crank the heating till 11pm, and then ‘sip’ the heating until everyone leaves the next morning. So of course, you need a big battery to power all that heating. But wait… Solar Sucks In Winter - Sorry ‘bout it. That system we spoke about, those 20 panels; they’ll generate about 40kWh on a typical summer day. But in winter, you’ll be lucky to get 30kWh. But most homes don’t have a 35 degree north facing roof. So 20 panels generate closer to 20kWh per day. And this hypothetical home we’ve been talking about (that uses 25kWh per day in summer), probably pulls 50kWh per day in winter. And of that 50kWh, 15kWh is probably pulled during the 9 – 5. Fridge, freezer, hot water heating, maybe a spa – whatever it is – even with nobody home, there’s still power use during the day. So, shit – of the ~20kWh these 20 panels are spitting out, more than half of it is chewed up by the homes base loads. The difference goes into the battery. And what’s the difference here? ‘Bout 10kWh, if you’re lucky. … So even though the house uses 50kWh per day in winter, there’s no point having a battery bigger than ~10kWh. It simply won’t get charged. You’re The Worst Salespeople Ever No, we’re not. We’re just saying it like it is. In summer, you couldn’t possibly use all of your solar. And in winter, you couldn’t possibly charge a huge battery. But you can still save a shit ton with solar. And the good news is, you don’t even need a battery to eliminate most of your summer bills. Read this . And this . And watch this. But if you want to reduce your winter bills, you’re going to need a battery. If it adds a year or two to your solar-system payback period, it’s nothing in the scheme of things. Especially when you consider the blackout experience. (Its awesome these days)! So, What Do I Do? Prioritize north, if you can. A north roof with a pitch of 15 to 45 degrees is ideal. North produces the most energy in winter, which gives you the best hope of charging a battery. If your roof has some north, and a bit of something else – prioritise north AND west. We love west, because west produces energy until the summer sunset, which is when you might want to cool your home. If your roof is East and West; look very closely at the winter production estimates, because most east-west systems struggle to charge even the smallest batteries in the 3 coldest months of the year. You Didn’t Answer My Question – How Much Storage Do I need? … Sorry, here’s the framework. Subtract your winter day time energy use from your winter solar production. The answer reflects the size of battery you should consider. You could buy a little more, but again – consider your summer evening loads, and ask yourself – do you want to spend a few grand extra (or more); just for it to be a pretty box on the wall providing little financial benefit? Does Equity Solar Brokers Support Solar Batteries? Heck yes we do! We love seeing our clients get batteries. About one third of them get batteries with their solar purchase. We’re not against batteries. We are obsessed with helping kiwis get a great return on their investment. We achieve that through smart solar system design and anonymous quote procurement, which is our leverage to getting sharp solar quotes. Everyone has a different solar objective - and we're all ears. Can't wait to hear yours. In a time of rising power prices and grid instability, batteries are awesome. And guess what – we’ve never had a client regret buying a battery. One client called to tell us they had a 2-day powercut, but only found out when the neighbors swung by. Priceless. Need a hand with system design? That’s what we do best. And we’ll get you the best quotes in the market while holding your hand every step of the way. Chuck your deets below, and lets do this.

What Happens After You Say “Yes” to Solar?

By looka_production_130270016 • January 24, 2026
Before your details are shared with a solar company, here’s what you should know about what happens next — and why this process doesn’t move at Uber Eats speed.