So your home is three phase. Maybe you should get a three phase inverter. But maybe not!

Load balancing inverters, also known as 'asynchronous generation' are pretty sweet!

You’ve got a three-phase power setup, and you’re diving into solar? Nice one! But here’s the thing: three-phase homes have unique quirks that can leave you scratching your head when it comes to solar design. Sit with us as we do our best to explain the options.


What is load balancing? (Or Asynchronous generation)

Picture this: your home is running on three phases of power. Parts of the house sips energy from phase 1; and other parts sips energy from phase 2 or 3.

Your home has unbalanced loads. All 3 phase homes have unbalanced loads. Load balancing inverters, capable of 'asynchronous  generation' enable the distribution of solar to the phase(s) that need it, in an 'unbalanced' measure.


Instead of pouring all your solar energy onto three phases equally, load balancing distributes the energy unequally, according to where your home is demanding energy.


Why might it matter for your three phase home?

  • Efficiency on All Phases: Without load balancing, some of your solar energy might go to a phase that doesn't need it.
  • Buying on one phase, selling on the other: Further to the point above, with a simple three phase inverter, incapable of 'load balancing'; you could be selling solar to the grid on one phase, while paying your energy retailer for power on another phase. In simpler terms, with a simpler & cheaper inverter, your solar gets wasted when you could be using it!
  • Stay Grid-Friendly: New Zealand’s power grid has rules—loads of them. Load balancing makes sure your solar system plays nice with the grid. (More notes on this below)
  • Maximise Self-Consumption: Solar is all about saving money, right? Load balancing helps you use more of the energy you generate instead of sending it back to the grid, with some caveats detailed below.
  • Future-Proof Your System: Want to add a battery later or upgrade your setup? Most solar inverters with the load balancing function are also 'Hybrid' or 'Battery Ready'.


What size system makes sense?

For reasons detailed in depth below, we'd say three phase systems really come into their own with 9kW or more of panels, on a 10kW three-phase inverter.

If a system can have 12+ kW of panels on a 15kW inverter, three-phase load balancing really 'hums', as a 15kW inverter can do 5kW per phase of power delivery. (5kW per phase is a great amount. The 1st and 2nd model of the Tesla Powerwall offered 5kW continuous output, and their clients are really happy!)


Are their downsides to load-balancing inverters?

Sure are. Load balancing inverters can only output up to one third of the rated output on each phase. EG; a 10kW inverter cannot put more than 3.3kW on each phase, even when operating in load-balancing mode. This means that the spec sheets are very unclear on the limitation to their peak power output.


What's peak power output?

Some solar inverters, mostly the ones designed for single phase, can output more for a short time when in off-grid mode. EG; a single phase 8kW Sungrow Hybrid can deliver over 13kWh for 10 seconds, which is HUGE and helps the inverter cover the demanding start up current from the likes of water pumps and large ducted heat pumps.


How to get the most peak power output for a great grid-backup experience


Three phase 15kW Hybrid inverters

A number of our clients have opted for 15kW, three-phase inverters. They're over the moon with their systems! 15kW continuous output is a wonderful amount for when the grid goes down. But... It still has it's limitations. Sometimes 5kW of output isn't enough to start a water pump, which is less than ideal.

With a 15kW three phase inverter, you need a ton of batteries to enable the 15kW continuous output. Typically if your system has less than 20kWh of batteries, you may only get 8 - 12kW of continuous output.


Single Phase systems might be the best choice for homes with a water pump

Installing a single phase solar setup may be the only sure-fire way to keep your water pump backed up in an outage. But with the immense downside of export limitations, 'single phasing' your home also has downsides. Despite the downsides, the single phase idea should at least be considered especially as most inverter manufacturers are now offering single phase inverters that can do 10kW continuous, and even more for short bursts!


Is it OK to install a single phase solar system on a three phase home?

Sometimes. The simple answer is; if your solar system is less than 13kW, it might make sense to go single phase, but it all depends on the appliances in your home and your overall preference once you've got a grasp on the technicalities. Our job is to inform you of the options and the potential upside and downsides.

*Disclaimer! Sometimes the solar companies in our network have different ideas to us, and that is absolutely OK. They'll often detail their thoughts in their quotes, which is great because it means we get honest feedback from the market while also retaining a mostly apples to apples quote comparison. By that we mean, in the quotes we procure, the number of panels and amount of batteries tend to be similar, but the inverters tend to have their differences.


More on doing a single phase solar setup on a three phase home

The idea here is that your three phase home is most likely made up of single phase appliances, except for maybe a couple of appliances, which may include an induction hob, water pump or ducted aircon. If those appliances use more than one phase, a single phase inverter won't be able to keep them live in a grid outage, but 99% of the time when the powerlines are working, solar may provide the energy for half or 1/3 of their usage demand.


Ask yourself; "do I need the most power hungry appliances working in a grid outage?"

... If you were trying to heat the whole home with your large ducted heat pump, how quickly would you discharge your solar battery?

... Maybe in a power outage scenario, it would be better to wrap up in a blanket and enjoy Netflix with a hot cut of tea, in the hope that your solar battery could last until the morning?


If the most power hungry appliances aren't necessary when the grid is down, leave them out!

The best solar companies take immense care with their customers, and their switchboards! One aspect of this service includes creating a separate group of circuits that remain live when the grid goes down. These separate backup circuits should absolutely contain your fridge and freezer, the room with your wi-fi modem, the lights, and maybe a couple of other things you love such as the TV or the very efficient heat pump in the living room. With the right sized inverter, you should be able to keep the water pump connected!


To ensure your batteries don't discharge in just a couple of hours, leave power hungry appliances off the backup circuits.

These may include;

  • Underfloor heating
  • Your bedroom heat pumps
  • The pool pump
  • The Spa

Remember... The goal is making it through the night until the sun rises. Having wi-fi when your neighbour doesn't is a luxury by our standards.


If you end up going single phase, here's some more insights into how it works

The solar company will have to move some of the appliances from the two phases that won't benefit from solar, to the phase that's getting solar installed.

  • This can mean that your home pulls a lot less from those two non-solar phases, than it did in the past.
  • As you're installing solar, the new phase that's loaded up with most of the home won't be using much power anyway!
  • If you're getting a single phase-system larger than 8kW, we absolutely recommend you get a battery.
  • To ensure the local lines company remains happy with your single phase system, some of your house will need to be excluded from solar and kept on the other two phases that don't have solar. Think about appliances that run at night, and also aren't crucial in a power outage.


A key consideration with single phase solar systems

Most regions in NZ only allow a 5kW solar-energy export per phase.

  • This means that single phase solar systems start to run into limitations once they get over 7.5kW peak output (about 17 panels).
  • On 6.5 - 8.5kW systems, those limitations typically only occur during the sunniest hours in the sunniest months.
  • Larger single phase systems can be designed in such a way that these limitations have minimal impact on efficiency. Examples include
    - Smart battery controls through the battery phone app
    - Hot water timers at peak hours
    - Purchasing solar batteries that are expandable (BYD, Sungrow, SolaX, Sigenery)
    - Limiting charge speeds on your solar batteries so that in the same moment, some energy is exported and some is stored.
  • If you end up going single phase, serious thought needs to be applied to mitigating the solar export limitation. In any case, we wouldn't recommend anyone gets a single phase system larger than 14kW, because at that point, export curtailment is a continuous challenge.


A note on making the grid unstable - you pay line charges for a reason.

Some solar companies will tell you that installing a single phase system on a three phase home is poor practice, for reasons primarily around grid stability.

This point has tons of merit, and we wouldn't go so far as saying that they're incorrect.


Grid stability isn't your responsibility to maintain.

Our two cents; If the regulators believed single phase systems on three phase homes were soon to cause unmanageable instability to the grid, they would change change the reg's in a heartbeat. But 5kW exported from a solar system barely moves the needle, so there isn't any talk of changing regulation.


Maybe you can get a 2-phase solar system?

... Lets discuss that in a consult. Lots to unpack 😘


Why Trust Us?

We know solar can feel like a lot of jargon and numbers. But that’s where we come in. You don’t need to master all the technical details; as we do the heavy lifting for you by designing a solar system that ticks all the right boxes, including price.


Still deciding whether you need a three phase solar system? Leave us your details below so we can talk through the ideas that relate to your objectives.

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

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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.