Single phase power limiting feed in amount?

[AmaraS]

Yesterday I was given a quote to get a battery attached to our solar system. The bloke tells us that us being on single phase power is limiting us the amount of power we can feed back in to the system to a maximum of 5kWh and that we would need to upgrade to 3 phase in order to feed back more than this. People who I have spoken to think this is a bit of rubbish - can anyone confirm or deny this please?

[John-T]

@AmaraS 

What state or territory are you in and who is your Distributor ?

I am NSW,

My Distributer is Endeavour Energy.

My retailer is AGL.

So for NSW residents that have that combination of Distributer & Retailer

Endeavour

Single phase: Up to 5kW 3-phase: Up to 30kW

EDIT: I am Export limited to 10Kw so I get the FIT.

This is just to give you a starting point but in general on Single Phase a 5KW inverter is the limit for exporting to the grid. This could be different in other states and with other Distributors.

Though if you are getting a Battery I would be utilizing that from sundown to sunup then letting the sun recharge it during the day. 

There are some very knowledgeable people on the forum and I am hoping somebody in particular that really knows his stuff spots your post. Apologies for not being able to help you any further.  

Regards 

John 

[AmaraS]

Thanks John. I am in QLD, my retailer is AGL and I assume our distributer is Ergon.

[John-T]

@AmaraS 

You are welcome. To the best of my knowledge current as of August 2021 in QLD

Ergon Energy (Regional QLD)

Single phase: 10 kW inverter limit, 5 kW export limit. Three phase: 30 kW inverter limit, 15 kW export limit. Battery inverters do count towards phase inverter limit.

Kind Regards

John

If anybody feels that the information above is incorrect feel free to correct me. 🙂 

[John-T]

And for Energex in QLD

Energex (SE QLD)

Single phase: 5 kW inverter limit, 5 kW export limit. Three phase: 15 kW inverter limit, 15 kW export limit. An installer we trust has advised that Energex regularly approves 10 kW inverter limit per phase, so long as export is 5 kW. Battery inverters do count towards phase inverter limit.

Kind Regards

John

[John-T]

Just to Clarify,

I have a 3 phase 8.58kw Solar system with an 8.2KW inverter and I am export limited to 10KW though I could never feed that sort of power into the grid as my system is smaller than 10KW. My location works against me as well with the cloud cover being relentless & never ending most of the time.

Regards

John 

[AmaraS]

Thanks again John for the info. Puts me in a bit of a pickle because if I upgrade to 3phase then I can feed more back in, but we only have about a 10kW system, so the cost of upgrade probably wouldn't be recouped in quite some time.

[John-T]

Back in 2019 at my old location I was quoted around 6K to go 3 phase and that was for overhead wires feeding into the house so I passed on that.

I shudder to think what underground wires would have cost.

Regards

John

[NeilC]

@AmaraS @John-T 

In all of these discussions did you think about the increased costs of having three phase, not the install cost but the Supply charge.

If you have three phase then you have three supply charges, so lets say you pay $1.00 a day for supply charge then you have added $2.00 a day to your costs. Now to make up that extra $2.00 you have to generate (at $0.05 a kW) an extra 40kW every day.

The limit's specified are in kWH so you can export somewhere around 40kWh a day with most 5kW systems (that is for each phase).

Thus in most circumstances negating any benefit you have gained.

Just for info here are some stats for the output of my Solar System over the last 3 years.

Year	Total	Monthly	Daily
2020	9444.8	787.1	25.8055
2021	9582.6	798.6	26.2537
2022	8891.5	741.0	24.3603
Average	9306.3	775.6	25.4731

Now I have 24 panels, 6.6 kW, 5kW inverter.

In the old days of 20c kWh that would be impressive.

But with 5c kWh I would be spending $1.00 a day on supply charges and thus based on the Average daily figure I would be loosing 20kW a day for supply leaving only 5.471kW per day as Profit.

But that is incidental though because if I did not have solar then I would still have to pay the supply charge.

Interesting fact though that at 5c kW I would recoup back about $465 a year, but even this is misleading as some of that generation I consume, now this is the interesting bit.

Last billing cycle I generated 2575.5 kW, Exported 2166.105 and therefore I consumed 409.395 kw.

I have recovered the cost of the Solar Install in the first 18 months of the install, got paid  $108.31 for power generation but saved $163.76 by consuming some of my generation. This is a total of $272.07 for a quarter which you can see is going to be much more than the predicted $465. The yearly figure would be $1,088.28 which can be used as a guide to show how long it would take to pay off a solar system even at current prices.

Also I have a Heat Pump Hot water service (free from the Government, look them up) and it's set to heat the water from 10:00 am thus I am getting completely free hot water.

Anyway, I've added my two bob's worth.

If you like my reply please click the Like button to show your appreciation.

Cheers Neil

PS I have a spreadsheet that I keep ALL OF MY DAILY DATA and have done so since I installed this solar system.

[John-T]

@NeilC 

Thank you, I was hoping you would pop in and put your thoughts down. And as usual a very helpful post. 👍

My old house which I had till end 2021 was single phase. And I was not going to pay that sort of money to go 3 phase.

This new house 2 yrs old when I bought Dec 21 came built with 3 phase, hence why I opted for the 3 phase solar system which is doing its best with the constant heavy cloud cover. The highest my system has been able to produce on 2 occasions was a tad over 60Kw but those days were exceptional. I have yet to pull a full year as my Solar system was installed June 2022 so I require a year to set a starting point to work from. My "average" production so far is anywhere between 6Kw - 50Kw. I am in the Hawkesbury Nepean area of NSW so heavy cloud cover often hinders what my system can produce.  

22 X 390 watt panels 8.58Kw

Fronius Symo 8.2Kw Inverter.

+ Battery

Panels all on the Northern slightly west about 15 deg facing roof.

Gas averaging about 100-110 a quarter so in essence we use hardly any gas. So you can understand why i want to cut that out.    

And you have already read my mind I am looking at an all in one hot water heatpump replacing my instant gas, & gas cooktop with an electrical one making my home 100% electricity reliant. ( And you can count on it that I will look up the the Hot Water heat pump. ) I only require a small unit as it is just myself and my Daughter.

Thanks again NEAL, I do glean a lot from many of your posts and do not have the level of knowledge in the electrical Solar field as you have. ( Ex Telstra techie here ) so my knowledge is elsewhere etc.

PS: I like your production stats

Kind Regards

John