Hi all,
Am starting to look into Solar for my home and have been offered quotes for both single and 3-phase solar options e.g. single phase 8.8kw or 3-phase 10kw.
Does anyone have a view as to pros/cons of 3-phase?
Thanks
Solar - 3 Phase or Single Phase?
lawrele on 14/03/2024 - 08:40
Comments
I live in a 5 bedroom 2 storey house. Gas for stove top and hot water
Electric Car??? If no, then single phase will be fine.
However, do you plan on getting an electric car??? Might be something to future proof for…..
No electric car atm but quite possibly on the cards within the next 12-18 months…
@lawrele: Okay, so might be something to consider 3-phase.
What is the cost difference between the two systems? Because that might also be a factor on whether it is worth it.
I live in a 5 bedroom 2 storey house
The standard ozbargain house, nice.
You know what 3-phase is, right? This might help you.
Most people won't need 3-phase unless you have an Electric Car or a farm.
Also, what is the cost difference between the two systems? Because that might also be a factor on whether it is worth it.
Good guide. I looked up the smart meter, to check what ours was.
3 phase would also allow for a nice big ducted reverse AC installation in a 5 bedroom home.
I always thought that was the advantage.
But apparently nowadays a single phase system is as efficient as a 3-Phase.
Air conditioner specialist words, not mine.
Solarquotes has a blog article about it.
I have a 3 phase home with 3 phase solar. It's good, we have a big system and we can export a lot if we are not using it. But obviously the goal is to maximise self consumption.
But that article does highlight some downsides if you are planning a future battery setup.
we can export a lot if we are not using it
And get peanuts for it……..
But obviously the goal is to maximise self consumption.
100%
Just went and checked the app.
Over the past 7 months the solar credit has covered 86% of my electricity charges. And that's after the self consumption. We've been cranking the aircon on some of those hot nights too. Pretty good even with low FIT.Must have low self consumption. I get about $20 a month of credits.
@geekcohen: Right now or all year long? That's why I averaged mine out. Also I excluded bonuses like the referral credits.
@FezMonkey: In peak time like summer. 5c per kw/h, peanuts. I have a smallish system at 6.6kw and in VIC.
For solar, a 3-Phase will allow higher export which is a BIG plu$ … however … depending on the inverter you get you will NOT be able to generate power from solar during a mains power shut down.
With some inverters they will stay on and produce from solar during a power failure, feeding your household (and hot water) and hopefully replenish a house battery too.
It will NOT, of course, export energy but will feed the household. AKA Islanding.No sure if any 3-Phase inverters allow that.
Our Fronius doesn't. No mains means no solar.
New Fronius will. Wire to one powerpoint and keep your fridge going.
This is a 3 months
oldnew Fronius.As explained to me, it has to do with being 3-Phased.
Single phase Fronius (some at least) do islanding.has to do with being 3-Phased
That is no good. Oh well.
a 3-Phase will allow higher export which is a BIG plu$
How so? Its only 2kw difference in system size. All of 10cents per kw/h…….. if at full generation.
Single phase only lets you export 5kw, 3 phase means you can export as much as you want
Much as you want until you either run out of up front capital to install 15kw inverter plus 19kw of panels, out of roof space and need a roof extension, then you need to cut down half the trees due to shading.
Or the cash flow from exporting doesn't cover unexpected costs and your buffer gone into paying for a system.
People need to get serious and figure out how much power they use (change habits to use it when solar is shining) get the cost cost effective system (whether it is 6.6kw which is the norm or multiples of 6.6kw so next size up is 10kw inverter with 13.2kw of panels)
If you do buy a battery how much would you actually be storing. Considering a 10kw battery is $8k - $12k. My 6.6kw does 40kwh in the summer and we use 5kw so we could get 3 batteries (in winter we get about 20kwh-30kwh per day) and what is the payback.
Seems like it is a kind of who's got more money to throw at a problem that doesn't exist these days.
Am starting to look into Solar for my home and have been offered quotes for both single and 3-phase solar options e.g. single phase 8.8kw or 3-phase 10kw.
If they quoted you 3 phase I assume you have a 3 phase house.
Check whether there is limits on export per phase. In Melbourne most distributors limit to 5kw per phase.
There isn't big money on exports anymore so I'd suggest having a look at what your expected consumption and matching it up. Generally the rule is STC means the panels cost almost nothing. The installation and inverter is where it costs you.
big aircons, electric cars (now or future) three phase all day
big solar system three phase
Ozo energy
I have a 3-phase house but only single phase solar (12kW of panel and 10kW inverter).
It does not matter if you are consuming on all phases and exporting on only one, as net metering takes that all into consideration.
Issues can arise if you want to install a battery set up, especially now that the Fit is so low (mine just dropped from 13c to 7c/kWh). From what I have read so far (only just started looking at batteries) is that my set-up will only allow a battery to feed a single phase, so need to possibly adjust house configuration to ensure that essential items would be powered in event of an outage.
As someone else mentioned the Solar Quotes website has a trove of info and a number of books that can be downloaded free of charge (pun intended)
We haven't had a bill for last 3-years, but expecting ones in the future due to Fit reduction
Having 3 phase gives you the option of using 3 phase welders as well.
And car hoists
.
It would also probably help if you mentioned what city you are in. Rules vary around Australia.
If you went for a single phase system, for optimum self consumption all your day time loads should be on that phase. to Optimise this your switch board will need to be reconfigured, but it can't be too unbalanced. You would also just have to accept that some of your daytime consumption will come from the grid for the circuits not on the solar phase.
If you went with the 3 phase system all circuits will use whatever solar is available, without reworking your switchboard.
I was under the impression that all states mandated net metering these days so it calculates total consumption minus total export
You could be right, I installed a 3 phase system 10 years ago. and that was the case then in WA.
Dont know about NSW but in WA if you have 3-phase power pretty sure you need a 3-phase inverter now.
I'm assuming since you've been offered a 3-phase inverter you already have 3-phase power in which case I would opt for the 3-phase inverter also. This will even the solar load across the phases instead of pumping it all through one phase and I believe for most states allows a higher export limit.
10kW per phase, up to 30kW for domestic solar installations in VIC.
We are pretty limited in WA. 5kW single phase, "up to" 30kW for three phase but apparently they rarely approve that much, usually between 8-22kW.
However to qualify for the buyback scheme you can't have an inverter larger than 5kW anyway (and I don't think a larger export limited inverter will qualify either though it's not clearly stated) On top of that you need to go on the crappy DEBS program which only pays off-peak 2.25c/kWh from 9pm to 3pm and peak 10c/kWh 3pm to 9pm. I'm still on the older REBS program which is only slighter better with a flat rate of 7.135c/kWh, but if you increase your inverter size or panel capacity from when you signed up you get switched to DEBS too.
I would for sure get three phase solar, the buy back scheme doesnt matter as thats not much and will be phased out anyway. Just try to get the maximum number of solar panels that will fit on your house and the appropriate size inverter based on that. They will release sodium ion batteries in the future that will be much cheaper then the current batteries and ideal for home solar. Also having more panels will mean you get more power during cloudy days and get a electric hot water storage tank to make use of the solar also.
How big is your home? Do you have an electric car? What about stove top, hot water?