When single-phase solar beats three-phase for backup performance and value.

So you're looking at solar, have a three phase home, and would prefer not to spend more than $35k on your solar setup.


Sounds fair enough.

Single phase might be your best bet.


But if you have a huge home, happy to spend $40k or more, check out this blog.



My home is Three-Phase, why would you recommend Single Phase solar?

Here's the thing. Many three phase homes are three phase because when they were built, they were the only home on the street.

Back then, it made sense for the only home on the street to sip power from all three phases.

(Power lines carry three phases of power. Each phase is basically just its own cable. Three cables.)


But if you've got neighbours now, chances are the power lines are more than capable of delivering all your homes energy needs on just one phase, especially if you have a solar system and batteries reducing your demand on that phase.


Before solar, a client of ours in Mangawhai was pulling 30,000 kWh per year on just one phase. Generally over 150kWh a day, and he was away 3 months a year! Now he has a Tesla Powerwall 3 with 32 450w panels. A 14.4kW system. Cost him $40,000 - and represents the upper end of single phase solar systems.


So our loose rule is, if your home uses less than 15,000 kWh per year, you can probably get a single phase solar system and reap all the benefits of single phase.



But why not go three phase?

Because three phase homes are essentially split into three sections. One phase might hit the kitchen. One might hit the bathroom and living area. One might hit the bedrooms and/or the shed.


If you're not spending more than 35k on a three phase solar system, you would probably only be getting a three phase solar system with a 10kW three phase inverter. The downside here is that these inverters can only put a maximum of 3.33kW per phase.


So... Lets say the grid is up (like most of the time) and people are in the kitchen. The kitchen needs 5kW of energy for the oven and the cooktop. Well.... Sorry, it can't have more than 3.3kW. Even though there's 6kW of solar energy cycling through unoccupied rooms and then then being sold to the grid!


And your water pump? It might start with 3.3kw of output per phase. Chances are it will be fine - but it's not 100%. You would need to spend another $2000 (at least) to be sure the water pump will fire up without a hitch.


Small three phase solar systems are underpowered, inefficient, and put simply - an average deal if saving money now  and later  is your goal.

The only solution is to spend more, or - go single phase if your home can be set up for it.


Keen to spend less than $30k on solar + batteries? ... Single phase might be your best option, even on your 3-phase home.

Happy to spend $35k + ... ? Ok sure - go and read our 'Behemoth Blog.'


Single Phase Solar: Built for Backup Brilliance

Single phase solar systems aren’t just simpler — they’re smarter when your goal is backup resilience. Why? Because a beefy single phase inverter can throw down some serious power when it counts.


Take the 8kW Sungrow Hybrid — it can push over 13kW for 10 seconds. That’s enough oomph to start up pumps, power heat pumps, or run the essentials without breaking a sweat.



But how much money can a single phase system actually save me?

Tons! Arguably more than a small 3 phase system will save, because you won't have to struggle with the inefficiencies of a 3 phase home and 3 phase inverter.

But this is only true for small to medium homes with small to medium sized systems (14kW of panels being the upper limit).


How is this possible?

Load shifting. The sparkies on install day can move most of your home onto one phase, so that solar powers most of your home.

Three phase appliances can't all be shifted, but the truth is - most appliances are single phase.


In town, most new homes are single phase. So - yours can be too! But be aware - if you're a seriously high power user, going single phase may not be ideal to grid stability in your area. But again... If you're a really higher power user, we would never recommend a single phase solar solution. Three Phase would be the way.


So... Most of your home can be shifted to one phase ONLY IF you are a low to medium power user. By that, we'd say if your home uses less than 15,000 kWh a year, you can probably do a single phase system WITH batteries for maximum savings and maximum energy independence.


Will it cost me an arm and a leg to 'downgrade' to single phase?

Hey! Hold your horses! We're not suggesting you downgrade to single phase. Absolutely not.


We see many three phase homes paying the same line charges as single phase homes. For most, having a three phase supply doesn't cost any extra.

So - keep the three phase supply. Just put the solar on one phase, and put most of the home on that one phase. The installers will re-order things in your switchboard to make the most of your solar energy, without 'downgrading' your home to single phase.


So - keep your three phase, and if you have three phase appliances or equipment, you've still got the grid for most of their energy. All good.

You'll save tons by powering almost everything else with solar.


What About the Grid, Bro?

We get it. There are purists out there saying, “Single phase on a three-phase home? That’s not proper!” But look — if it was truly a grid-wrecker, the regulators would ban it yesterday.


The truth? A single phase system on a three phase home does the same to the grid as a single phase system on a single phase home. The 5kW export limit is just the same.  If you have the right size battery, timed loads such as hot water or pool pumps, and a mustard seed of common sense, your system will be a treat for all parties.


However, this is not a guarantee. We'll advise you, and then the sparky who wins your job will confirm.


Things we consider are:

  • Population density
  • Peak load demand in your home
  • The size of the 3 phase cables. Are they 32 amp or 63 amp? It matters, a lot.
  • If your 3 phase cables are only capable of 32 amp per phase,  we'll have to educate you on the impacts, and may recommend a 3 phase system.
  • Size of battery & generation respective to your homes energy demands.



So... Should You Do It?

Let’s break it down like a power bill:

  • Want a seamless backup experience when the grid goes down? ✅
  • Want ALL of the solar available to you when you're cooking in the kitchen? ✅
  • Don't want solar being sent to the bedrooms when they're empty? ✅
  • All good if your multi phase equipment still takes some energy from the grid when the sun is shining? ✅
  • Happy to not have your multi phase equipment working in a grid outage? ✅
    (Typically things like a welder - induction hob, underfloor heating).


Then yes, single phase might be the best way to get an affordable solar system that absolutely punches in the grid-backup and overall savings department.

And sure, some parts of the house might not get power when the grid’s out. But we’re talking survival here — not comfort.


Fire up the BBQ, grab a Hot tea, enjoy your Wi-Fi and Netflix.


Tips to Make It Work:

  • Battery is a must. If you’re going over 12kW on single phase, get a decent battery. Non-negotiable.
  • Don't get an array larger than 15kW on single phase. Anything more is total overkill and its better to get a juicy 3-phase inverter (15 -25 kW).
  • Don't start charging your solar battery until peak time, so the battery takes the energy that would be curtailed by the 5kW-per-hour export limit.
  • Be smart with your exports. Use apps and timers to avoid wasting energy during the sunniest hours.



In Summary...

If your solar goals include resilience, simplicity, getting bang for your buck, and saving as much as possible   — a single phase system could be the way forward. Yes, it’s got export limits. And yes, it won’t power all of your underfloor heating or 2-phase hob.


But it's the only sure-fire way to ensure consistent backup power for a very affordable price (compared to juicy 3-phase systems).



Why Trust Equity Solar Brokers?

We don’t install panels, push brands, or sell the latest 14 panel special.


We help you get the best solar deal for zero hassle, by procuring quotes from the best solar companies, then cutting through the BS to help you identify which quote best aligns with your solar objectives.


Feeling bogged down with all this technical jargon?


Flick us your details. Let us simplify the entire process of going solar.

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.