May the (electromotive) force be with you!
I’m thinking of writing a screenplay. The movie’s name is “3-Phase Solar Wars : The Phantom Imports”. Here’s the opening scene:
“Quite soon in the future, in a suburb not very far away….
It is a period of civil war. Solar owners, striking from over a million rooftops, have won their first victory against the evil Electricity Empire.
During the battle, these plucky rebel homeowners managed to get their electricity bills down so low that they are on the cusp of destroying an entire electricity retail industry.
But now the Empire’s sinister agents have a plan:
They’ve identified a weakness in hundreds of thousands of rebel bases that rely on a 3-phase supply.
If you are a solar-rebel with 3-phase then be afraid. The Empire has spotted a pile of your cash on the floor and have figured out how to legally take it from you.
And the scariest part is this: you will probably never understand the dark forces that cause your bill to rise 10, 20, 40% overnight.
You see it’s not a price rise and they haven’t hatched a plan to make you use more power.
Rather they are going to deploy a droid from their work force, probably with the title “embedded systems engineer” to change a handful of lines of computer code. Once this mission is complete they will engage one of their fluoro vest clad meter readers (aka Stormtroopers) to discreetly upload the new code to your 3-phase solar meter.
You’ll never even know that the box on your wall that silently counts your solar exports and grid imports has now been subtly reprogrammed in the dark side’s favour.”
Far fetched vision of the near future? Maybe not. Here’s why…
A couple of weeks before Christmas I got a call from a client who runs a national solar installation business. He had just read my blog post on 3 phase power and solar and wanted to share his recent experience of connecting solar customers to 3 phase.
He told me that for the first time he was starting to see 3 phase import export meters configured in a way that was seriously reducing solar owners’ payback whilst fattening the electricity retailers’ profits.
How can this happen? Here’s how:
Many homes in Australia have a 3 phase supply. Many 3 phase homes who have solar have a single, 1 phase inverter connected to one of the home’s phases (usually the blue one).
This is a perfectly reasonable way to install solar. My personal solar system connects to a single phase of the house’s 3 phase supply.
The house’s 3 phases are then connected to a 3 phase solar import/export meter. This meter calculates how much solar exports to the grid, and how much of the solar energy is being ‘self consumed’.
For most homes self consuming solar energy saves about 35c per kWh because that is what it would cost to buy from the grid. Exporting solar energy is generally worth only 8c per kWh.
So obviously you want to maximise self consumption and minimize exports.
How 3 phase meters usually calculate exports:
Traditionally all 3 phase import/export meters have calculated exports like this:
1) Look at the total amount of energy being consumed on all 3 phases
2) Look at the solar being generated on the single ‘solar’ phase.
Subtract (1) from (2) to calculate the exported energy.
This is good for the homeowner. If the sun is shining and they are generating, say 3.5kW of power, but their appliances are consuming 1 kW on each of the 3 phases, they are officially exporting 0.5kW (3.5kW – 3kW) and importing zero kW from the grid. So they are earning about 4c per hour for their efforts. Not a lot, but better than paying for electricity!
How 3 phase meters could be hacked to benefit the retailers:
Let’s stay with the scenario above and consider what is actually happening to the electrons in the 3 wires.
On solar phase, we are generating 3.5kW but consuming 1kW. Therefore we are sending 2.5kW back to the grid on the solar phase.
On the other 2 phases, we are consuming (importing) 1kW per phase.
So if the meter gets reconfigured to only count exports on the solar phase, then the financial effect is this:
The homeowner will be earning 2.5 x 8c = 20c per hour for their exports. But will be paying 2 x 35c = 70c per hour for these imports. The net effect is a cost of 50c per hour to the homeowner instead of them earning 4c per hour.
Do you think the electricity retailer would prefer to pay out 4c per hour or earn 50c per hour from hundreds of thousands of 3 phase solar homes with a 3 phase supply?
According to my contact, he’s tested some 3 phase meters and has discovered that some are now being configured the latter way: i.e to calculate exports only on the solar phase, to benefit the electricity company at the expense of the unknowing solar owner.
To my knowledge, there is no standard or contractual basis to enforce how these meters should calculate the exports. The electricity companies that own them may well be legally able to change the software in the meters at their whim, as I’ve never seen it specified in a supply contract.
Further, my contact told me that the electrician that first discovered this was forced to remove his findings from an online forum because his job/licence was threatened. I wouldn’t be surprised if Lord Vader himself made the threat.
Maybe my opening sequence is not so far-fetched after all?
What should a solar buyer with 3 phase do to protect themselves from being charged for these ‘phantom’ imports of electricity?
The safest option is to get a 3 phase inverter. Unfortunately this will add approx $500-$800 to the price of a 5kW system compared to using a single phase inverter.
Or, if you don’t have any 3-phase appliances, you can stick with a single phase inverter but ask your electrician to connect as many daytime loads as possible to the solar phase.
About Finn Peacock
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Hi Finn, Hmm….
Well if this is happening under the Electricity Act, dependent upon which state it would be illegal.
Utilities cant and should not confuse Policy with the Law , they are two different things.
Ref:// https://www.business.qld.gov.au/industry/energy/electricity-industry/electricity-regulation-licensing
You can also download the Addendum with the FIT and inverter size changes.
The Utility must compile with the Electricity Act.(which I am sure they are.) In QLD Solar systems (3 phase residential assumed) must be Nett metered. In fact in QLD all solar systems at residential must be Nett metered if they want the FIT under the Act.
This means the single phase inverter at a 3 phase site (using your example) will give you your first result in your article.
“This is good for the homeowner. If the sun is shining and they are generating, say 3.5kW of power, but their appliances are consuming 1 kW on each of the 3 phases, they are officially exporting 0.5kW (3.5kW – 3kW) and importing zero kW from the grid. So they are earning about 4c per hour for their efforts. Not a lot, but better than paying for electricity!”
It has been Nett metering due to the QLD Solar Bonus scheme as your know ,per kWh originally being higher than the kWh unit rate of consumption. Now that the feed in tariff(FIT) is reversed, they cant have it the other way, and the Electricity Act has not changed.
As per your second example.
I have wired hundreds of three phase sites residential and now commercial. (including my own home). I am very happy if the Utility reprograms my house intentionally, in their favour as under the Law I would love a big bucket of money when I sue them as being in breach of the Electricity Act.
I am sure it is an honest mistake the Utility end. Isn’t it?
Another reason to go with a quality Solar company, if you have a three phase site , in QLD you should have a 3 phase inverter. I am aware these were not available a number of years ago. Also a quality Solar company should also be aware of the Electricity Act in the state they install within, and hence how to ensure the customers are getting what is expected from their solar system and meter.
If your contact is in QLD , I am very happy to provide a contact to the Ombudsman and a Solicitor. (Unless it is an honest mistake on behalf of the Utility!)
If it is in NSW Gross metering cant then be changed back to Nett metering.
If somehow it becomes Law in the future(which it wont!) I am sure the “Alliance customers will be adding extra inverters with battery packs at their home bases to ward of the Evil Electricity Empire.”
Great Article, I hope it isnt really true!
Thanks Terry, I know someone reading this that will be very interested in your comment!
i am pretty sure that Finn is right, somehow the power companies they are getting away ripping of households who produce solar excess power.
i am perfect example, come to my place, i have all records, several previous years of consumption which was very similar day after day, year after year 99%.
after i got 10.5kwth solar panel with 3phase SMA inverter installed my power bill jumped up instantly.
i produced aprox 18000kwth in a year, my usage aprox 8000kwth same year and on top of this lumbered with aprox $2000 power bill, figure this out.
By the way i have all and every record going back for 30 years, would you like to look into this, i have complained of course, i have the meter tested but they only want to test the meter is calibrated correctly, which of course it is, but when i ask for the program that is in meter that measures what goes in grid nobody wanted to answer my call or listen.
i am in melbourne and SP ausnet in the network provider, i am with energy australia for the supply.
So if you think you have the know how please look at my example.
thanks
Albert
Hi Finn, I like your last sentence about changing the loading in the house. I have 3 phase supply, and am about to install a 5 kw solar system. I have a 3 phase motor on my elevator which runs from a separate area of the building. I will isolate this motor supply. the rest of the 3 phases to the house will be joint to a single phase supply to which the solar system will be connected,,, this was all planned before I read your blog. Again I warn people to get a detailed quote and check the item prices on ebay etc. someone here got a 4 kw system which should have cost $5,700 after STC credit,,, the owner paid $15,000 for 16 panels and 16 Enphase inverters and 2 hours installation.
This is a scam like the pink bat scam.
regards j n
Hi John,
Could you let me know which company charged $16K? Either reply to this comment or email finn_AT_solarquotes.com.au
Cheers,
FInn
Hi!!!
Terry Davis, love what you’re saying up there, but to be honest, I don’t have a legal team on staff that can go through that, pick every hole in the legal standpoint / policy point and how they interact. Policy and Law are tied together intrinsically, whether we like it or not.
If you click on Finn’s first link in the article, below this, you’ll see many consumers experiencing this happening, to them, right here, right now and in QLD.
http://www.solarquotes.com.au/blog/3-phase-solar-what-you-need-to-know-about-connecting-solar-to-your-3-phase-supply/
Please also recognize that the opposite is true.
A 3 Phase house / business, with a 3 Phase Inverter, faces the same problem.
A 3 Phase Inverter exports power across 3 Phases, evenly, as they are designed to do.
If the 3 Phase meter is not netting out those 3 phases, the same happens.
For eg
A 6kW, 3 Phase household, with a 3 Phase Inverter.
Generally running 3 phase Air Con, but most other / all appliances are on 1 phase.
Therefore, the inverter is pumping out to the grid 2kw x 2 and the property is consuming 1 phase of 2kW.
If that meter is not netting out that, the damage is even worse.
Free power to the Empire!
…Anyway, we’ll win one day….
– If you have a good installer, with good products, these “Jedi Knights” can wire your house to be future proof, and fight off the Empire.
Renewable’s is the answer to almost everything…
Anonymous…
The situation described cannot happen. The meters cannot meter the phases separately. This is a complete fabrication without even a grain of truth.
This has been a sublime issue for a long time.
The ‘NEM Rules’ state a meter is to be treated as whole energy measurement in the case of 3-phase meters. Each phase is not to be treated as a separate metered supply.
AEMO and AER must finally recognise the abuse, comment on it, and get involved to retrospectively ‘fix’ it in favor of end users.
This is an interesting subject, tried to get actual working details of meters used in Victoria and was met with the answer “details are in confidence and not available” was really looking for access to real time data that could be used to switch power hungry devices on or off
Okay this is what I don’t understand and is not clear.
I installed solar a 5KW system and was asked do I have 3 phase power to which I relied I have a 3 phase air conditioner.
So, the install was a single phase SMA 500tl series and the meter was an Atlas EDMI MK10a
I suspect this is a single phase meter?
So, do I have a 3phase power supply ?
Or, is my air conditioner motor running on 3 phase supply from a single phase curcuit and how is my solar power supplying to this circuit.
How does my normal grid supply this curcuit
I checked the air is 440V 20A .
welcome to democracy,
unfortunately i am also one victim of this power companies, i have installed couple years ago 10.5kwt panels with 3phase SMA inverter, my power consumption per year aprox 8000kwt which was very similar for several years, and i produce 18000 kwt per year, but it gets better, they still charged me $2000 aprox in same year, figure this out?
Ok so what can we do, how can we repel this legalized gangsters, can we some how prove what they been doing and make a class action, the mass always wins.
If you have the right expertise in this area dont be afraid to let everyone know.
Hm, I am looking into solar for a property with 3-phase supply, for many reasons 3-phase inverter makes the most sense, however I now wonder if a crafty power company may “net meter” each phase – recording net import on one phase to the import register at say 30c/kWh and export on the other two to the export register at 12c/kWh, for a 28c/kWh profit ‘distributing’ power via circulating current in the transformer primary.
Oops only 18c/kWh, slightly better, but the principal remains.
Hi Finn,
About to do my first solar install and after reading these articles I have a couple of questions as the two companies provided by you seem to give contradictory advice.
Our daily usage is 13-14kWh. We have 3-phase power to our ducted aircon, 6.5hp (13-14kW).
First installer initially suggested a 5kW with central inverter or 3kW with micro inverters. They asked for a copy of the usage charges and photo of the meter board. As the usage charge had one period where we spiked to 23kWh for that quarter, they came back with a revised quote of a 5kW micro inverter system and additional charges for 3-phase metering changeover. They are suggesting a 5kW system using 20 x 270W panels and 20 x S230 Micro inverters. This ‘sales-person’ told me that the system is configured single phase, and the meter will get the full 23kW generation on 1-phase and then send it out and back in on the other phases.
Second installer initially was suggesting a 5.4kW system using 20 x 270W panels and 20 x S230 3Ph Micro inverters and a Digital Bio-Directional Net Meter. He has revised his quote down to a 3.24kW system dropping down to 12 panels but changing to the S270 inverters. Again he has quoted them as 3-phase units.
So my questions are:
1) Are the S230 and S270 3-phase invertors or single phase? Internet searches suggest the latter.
2) Assuming they are single phase is it worthwhile making the array into three banks and having each bank feed one phase (acknowledge that this would involve additional cable runs to the meter box) or leave it a single bank and feed it in to just a single phase and hope that Sydney providers don’t rip me off as per this blog.
3) On a few other sites it is suggested to oversize the array to the inverter as you end up getting more bang for your buck (except on cold very sunny days when you may experience some clipping). With that in mind should I go for the S230 or S270 inverters?
4) What are your thoughts on Solaray? Are they not one of your clients? The reason for asking is that they are located three suburbs over but you didn’t include them in your recommendations, and were only offering two installers, with a third who is further away than Solaray.
Hi Matt, Ronald here.
First thing I’ll mention is, with the increase in electricity prices and feed-in tariffs in NSW at the start of this month, you may want to consider the larger systems. Using our comparison tool:
https://www.solarquotes.com.au/energy/
I see feed-in tariffs in NSW can be up to 17 cents. But note plans with the highest feed-in tariffs aren’t always the best overall.
1) Microinverters are always single phase, but as you mention, a group of microinverters can be divided between phases. I presume this is what is meant when they are referred to as three phase.
2) If you are not required to split the microinverters across the phases then you may as well save a little money on the installation and just have them put on one phase, which should be the one likely to see the most demand during the day. I would say it is very unlikely you will be ripped off. The fact it is now much easier for people with new solar to closely monitor their systems may have something to do with that.
3) Total PV capacity can be one and one-third or less of inverter capacity, and within that limit little to no output is lost overall. I wrote about why here:
https://www.solarquotes.com.au/blog/oversizing-solar-arrays/
So if it saves you money and it is within the 1.33 limit, then it makes sense to use S230 rather than S270 microinverters. (Note these microinverters are named after their peak output and their actual continuous rating for AC output are 220 and 260 watts respectively.)
4) Solaray are great installers. (All installers we refer to you are personally vetted by Finn and will be good.) Just who you will receive quotes from depends on a number of factors, including how busy the installers are. Just a give minute and I’ll get Jono, who usually handles these kinds of inquiries, to give you are reply…
“Hi Matt,
Our algorithm recommends installers in our network based on a number of factors. Their physical proximity to you is a big one. But other factors include:
– Whether or not the company is accepting leads for your specific request (for example, some installers elect not to take on customers who have a timeframe of over 6 months for buying solar, or for customers that want batteries)
– Whether or not the company has hit a cap for quote requests for the day/week/month – if a company elects to take 5 quote requests per day and you are the 6th – then you will be assigned to another company
I hope this helps clear things up – and by all means, feel free to reach out individually to Solaray to get a quote from them.”
Hi Finn,
Do you know if this is still an issue or have you shamed them into line?
We (Solar Analytics) implementing some changes to improve our import/export calculations for three-phase sites, which should help identify when customers are getting robbed.
If it’s a still a widespread issue we can put some effort into helping customers compare to billing periods more easily.
From what I’ve heard this is not happening any more. Yay!
The kudos to you for getting it out there!
Thanks.
Not true in New Zealand unfortunately. According to my both my line company & my power supply company all 3 phase meters in NZ are programmed like that by Electricity Authority legal requirements (and guess who advises the Electricity Authority). All retailers use the same meter programmed for billing purposes only to add each phase separately so no help in changing retailers.
Good on you in Australia having an organization which at least can stop that there.
Yes, i found that out recently. Had to put an extra NZ clause in the code for our savings calculations. Also recently found one in Australia that was being billed NZ-style after a customer noticed their bill was different to solar analytics.
I have a Sunna Inverter and an EM1200 Meter. I am concerned that the Meter display for PEAK is not deducting the solar that’s been used in-house.
As multiple calculations are possible, would the meter be able to do that- display total household energy consumption as if it all came from the Grid?
I live alone, use very little appliances and electricity and find it alarming that my solar exports are low but my usage high.
My system, 2000T, was advised by a consultant to on a good sunny day generate 8kwh. So if over 90 days, I contributed 197 to the Grid in full summer, then ave export of 2kwh a day, leaves about 5kwh per day used inhouse- that takes my consumption up to around 18kwh a day! Can’t be true.
My inverter reads 9876 Kwh, the meter export for solar reads 7100kwh.
This indicates that either only 2700 has been used in-house over 5 years or the inverter is on its second round of 9999 counts, meaning the inverter has produced over 18,000 kWh. – or, 9876keh should have been exported.
I am confused as to how to apply the inverter read to the EM1200 export read.
Either way, the Hugh consumption read does not seem to fit.
Hello Marie
Your electricity meter should be accounting for all solar electricity that is used in-house. If a meter is defective it will generally stop working or give an error message. It is very unusual for them to misread electricity consumption.
If your inverter says you have generated 9,876 kilowatt-hours over 5 years that’s an average of 5.4 kilowatt-hours a day. It is about what I would expect from a system with 1.5 kilowatts of solar panels. A system with 1.5 kilowatts of panels can produce 8 kilowatt-hours over a sunny day, but the average will be much lower. So to me it sounds as though you have quite a small solar system. But for one person it can be enough.
If you want to lower your electricity bills it is possible you will be able to find an electricity plan that is better for you. Many people with solar find they are better off with a standard tariff than with a time-of-use tariff, but it will depend on your electricity consumption habits. It may be helpful to change to a standard tariff if you use a lot of electricity in the evening which would currently be a peak rate for you.
Modern electricity meters, such as yours, are normally very accurate and it is very unlikely that it is not measuring your grid electricity use properly. While it is possible your rooftop solar system isn’t providing much power, any power that it does provide should definitely be reducing the amount of grid electricity you use.
Hi All,
I’ve recently (last week) had a 5KW Solis Inverter and Talesun solar panels installed at my home….QLD, 4 bedroom double storey with Central Aircon and a Pool & Spa and a 3 phase meter. My contract with the Solar Supplier/Installer includes a 3 phase Inverter, but on the day of the installation, the Installer put in a Single phase Inverter saying that as I have a digital meter, it would not make any difference if I had a Single Phase or a 3 Phase Inverter.
Should I insist on them replacing the Single Phase Inverter with the 3 Phase Inverter as per my original contract…(they claim that their is no price difference between the two)? I would appreciate any insight or help that you can provide…….as I am an ignoramus when it comes to this stuff!
Thanks in anticipation of your replies.
Hello
A three phase inverter is superior to a single phase inverter as you will be less likely to suffer from over voltage problems that can cause your solar system to shut down. I would definitely want a 3 phase inverter if that is what I had paid for. I don’t know of any 5 kilowatt inverter that doesn’t cost more for a three phase model so to me it seems they are ripping you off. If you can tell the name of the installation company I’d appreciate that.
I suggest telling them you want the three phase inverter you paid for and contact consumer affairs in your state if they give you any trouble. You can also let us know if they give you problems.
Hi Ronald,
Thank you so much for your reply and for clarifying my query. I will insist that they change my Inverter to a 3 phase one.
Will get in touch with the Company now and let them know.
Thanks for your help in this…..really appreciate it.
Cheers, Praveen
Hi All,
I have 3ph power and Email Q4 net meter, probably 10 years old now. I only use 3ph occasionally in my workshop. Currently my 2kW single phase invertor is connected on the same phase as all my house circuits, so no metering issues now.
I am about to install another independent 3kW pv system with 1ph invertor (to make a future battery install easier). I want to balance the phases by hooking the new invertor to a different and little used phase and maybe split my house circuits across as well, but this relies on all phases being combined for metering purposes.
My questions are:
Does the Email Q4 combine phases for metering purposes?
Who would be able to advise me about this?
Or if the meter program is uncertain, how do I test my installed meter to see if the phases are metered in combination or separately?
Hoping you knowledgeable folk can help me!
Cheers,
Rowan
Hi Rowan
If you are getting a new solar system installed you will be required to have your old meter replaced with a new smart meter and that will combine the phases for metering purposes. For example, if two phases are each drawing 1 kilowatt of grid power while the third phase is exporting 2 kilowatts of solar power the new meter will regard your property as using 0 kilowatts of grid electricity at that time.
The only way around this I can think of would be to install a solar system that is designed to never export electricity to the grid. Then you won’t have to change your current meter. But this means you won’t receive a feed-in tariff for any surplus electricity it generates.
Hi Ronald
Thanks for your help, I will talk with my installer about my metering options.
I live in a retirement village in the ACT with 6 x3 storey blocks (133 apartments )
What are the best possibilities for solar installation to provide returns to village use of power as well as to individual apartment use?
An embedded system?
Thanks for your excellent website
Hi Sue
One option would be to allow each apartment to have its own separate solar system, but I assume the amount of roof space available to each apartment would be very small, so this is not likely to be practical. But if not all the residents want solar perhaps there may be sufficient space for those who want it.
A more practical approach may be to install either one large solar system on each block, or large system divided between multiple blocks. If the retirement village is an embedded network where the village pays one electricity bill to the electricity retailer and then each apartment pays their share based on use to the village, then this can reduce everyone’s electricity bills and the solar system should have a relatively low cost per kilowatt thanks to economies of scale. If the village is not an embedded network it still can be done but it may not be as effective at reducing electricity costs.
I suggest contacting ACTsmart to see if they are able to help with information specific to the ACT.
Hi Finn,
Thank you for all your efforts in promoting truthful information about solar energy.
In your blog post you mention that your electrician contact “tested some 3 phase meters and has discovered that some are now being configured the latter way: i.e to calculate exports only on the solar phase, to benefit the electricity company at the expense of the unknowing solar owner.”
Is there a simple way to verify the configuration of a three phase meter?
We have a three phase supply and 10kW of solar panels, the power from which, overall, we almost always consume ourselves. However the single phase loads are not always in balance so we at times we export power on one or two phases while consuming more on the other phase than the panels can supply for that phase.
Our installation details are as follows:
Email EM3330 meter
SMA Sunny Tripower Inverter (STP 10000TL-20)
Enphase Envoy monitoring system with management access so can view the individual phases produced/consumed/imported/exported. (Recently installed)
Hi Richard
While this was a concern years ago, as far as we can tell all three phase meters are being configured correctly. It’s very unlikely to be a problem.
If you are concerned, you could check by waiting until, or arranging it so, one phase is exporting solar while the other two are importing grid power. Then you can check if your meter is measuring household electricity consumption as it should.
Hello Finn,
I still have this problem with AGL and when I spoke to the AGL rep he explained that’s how it should be. So my smart meter (from the AGL website) is showing that I’m exporting while I’m importing at the same time.
Will this be a AGL issue or is it a NSW issue?
Over what time period is the energy export/ import supposed to be netted:
5 min/ 30 min/ 1 hr/ daily??
It happen in real time, for every instant in time, in reality it is probably limited by the meter CPU, but it’s likely to be many hundreds of time a second.
Metering 3 phase electricity like this is illegal, mainly because the meter can’t measure accurately – see Blondel’s Theorem on wikipedia.
Finn really should know this, but I guess it looks like a reasonable thing to do if you don’t think about it very hard and/or you haven’t seen it before.
The long and short of it is you can’t measure phase-phase connected loads with three single phase-neutral connected meters whether you want to or not. Try it yourself and see what happens.
There’s an easy way to test for it if anybody is interested – the meters are so bent that they out themselves immediately.