Smart Meter Installed

[Andy Chee]

Andy Chee: The three phase import-export issue, I haven't figured it out yet, because it was not an interesting question financially (here) up until ~ 1 months ago. I think it's a very easy test, by placing a hair drier on another phase. And assumptions are nice, but I found reality much worse than that.

It shouldn't be that hard to confirm, just look at your energy bill!  Does your energy provider bill you for total kWh? or do they bill you kWh per phase?  maybe they send you three bills every billing cycle?!

[Siwastaja]

Andy Chee: The three phase import-export issue, I haven't figured it out yet, because it was not an interesting question financially (here) up until ~ 1 months ago. I think it's a very easy test, by placing a hair drier on another phase. And assumptions are nice, but I found reality much worse than that.

It shouldn't be that hard to confirm, just look at your energy bill!  Does your energy provider bill you for total kWh? or do they bill you kWh per phase?  maybe they send you three bills every billing cycle?!

It isn't obvious from the bill. For example for me, the billing strategy changed in 2022 or so. Bill itself did not show hourly data, so you can't say - they just show total buy, total sell energy. During the old times, billing was per phase, but as those were summed into the bill this was not obvious (and I did not receive three bills).

But if you added your own per-phase measurements and record the data at high sample rate, then you can reconstruct different ways to calculate the total sum. When you arrive close to the total values shown in the bill, then you have high chances you have found the same algorithm as used for billing.

Or, you can just ask the company. Obviously they are required to disclose the exact process on which the billing is based, so you don't need to guess.

[Njk]

I just noticed that one day last went they marked as "High feed-in".

I presume they think that's bad? 
And now it hasn't updated over the weeekend.
And I haven't had a single day yet where I haven't used at least some grid energy, which seems odd. But maybe this was some peak that couldn't be supplied by the solar at the time or the battery, which is possible, but I'll keep an eye on that.

If you have two properties, it can be difficult for you to be at two different sites simultaneously. So yes, I'm not always there, especially at winter since it's not a big pleasure to do a construction work at that time. But it seems that guys have a monetary incentive to install as much smart meters as they can, so they're using all the tricks

[Andy Chee]

they just show total buy, total sell energy.

As long as the provider quotes these buy & sell totals in kWh (NOT currency $ or €), that should be enough raw information to verify whether single phase export is offsetting unbalanced three phase import (or regular single phase import).

The fine grained hourly data can help in chasing every $0.001/kWh, but is not needed when checking for blatantly obvious meter misconfiguration or malfunctions. (e.g. export disabled)

[tszaboo]

Andy Chee: The three phase import-export issue, I haven't figured it out yet, because it was not an interesting question financially (here) up until ~ 1 months ago. I think it's a very easy test, by placing a hair drier on another phase. And assumptions are nice, but I found reality much worse than that.

It shouldn't be that hard to confirm, just look at your energy bill!  Does your energy provider bill you for total kWh? or do they bill you kWh per phase?  maybe they send you three bills every billing cycle?!

Well two things:
They changed billing recently, not a lot of experience (or statements) on what this means to customers. Meters have common hardware, but their exact settings are tailored for the country they are sold in.

And it depends on the algorithm, mathematically it's not that hard to see, that this below would be less advantageous for customers .
Total export = Integral every 10 seconds (Export P1 + Export P2 + Export P3)
Total import = Integral every 10 seconds (Import P1 + Import P2 +  Import P3)
It also depends on what the DSO does with the data. They are not going to keep 10s interval data, it's cumulative for ie. 15 minutes in Belgium.

[Njk]

Anyway, one positive thing: The smart metering provides a lots of people with occupation. And it's better than, say, a blockchain stuff, which is a pure waste of energy with zero useful effect.

[EEVblog]

7 days in a row now where it says around 1.8kWh imported.
Actual values are:
2.08
1.38
2.05
1.69
1.87
1.93
1.84

That's WAY too coincidental...
And on none of those days has my battery gotten to 20% and cut off. And you can see that exporting significant energy, biggest peak is 15.8kWh, which means my battery got full early and there was a ton of excess. Yet still I imported 1.38kWh on that day?

[Electrodynamic]

I'm in Alberta, Canada and the power company installed a smart meter on my acreage about 5 years ago. The reason they gave was it saved time and manpower by being able to read the meter remotely from a grid road. Fair enough but when they came back this year to replace a power pole I quizzed the workers a bit. They agreed it's easier to read the meter remotely and not have to enter my property and deal with dogs and stuff.

Then I said "I assumed you guys installed smart meters everywhere because variable rates and peak rate pricing was coming". He just smiled, then said you can be sure that's the next step.

The power companies also pulled a fast one here. The politicians like to brag about how cheap power is here and it's pretty reasonable at $0.12/kwh with a rural contract. What they don't say is the power companies have quadrupled the maintenance and administration fees to compensate for lost revenue. So now it's common for some people I know to see a $250 power bill for only using $50 worth of power.

I think they may have done this to indirectly penalize people with or thinking about installing small solar installations. So we can produce all the solar power we want to offset our power use but maintenance/administration fees plus peak rate pricing would all but ensure nobody makes a dime.

[Andy Chee]

That's WAY too coincidental...
And on none of those days has my battery gotten to 20% and cut off. And you can see that exporting significant energy, biggest peak is 15.8kWh, which means my battery got full early and there was a ton of excess. Yet still I imported 1.38kWh on that day?

Do you have access to your energy provider's version of the same data?

For example, my energy provider (Jemena) has a website where I can login to get my interval data, like so:

Not sure if your provider (Endeavour?) gives you a similar web page.

[EEVblog]

[EEVblog]

That's WAY too coincidental...
And on none of those days has my battery gotten to 20% and cut off. And you can see that exporting significant energy, biggest peak is 15.8kWh, which means my battery got full early and there was a ton of excess. Yet still I imported 1.38kWh on that day?

Do you have access to your energy provider's version of the same data?
For example, my energy provider (Jemena) has a website where I can login to get my interval data, like so:
Not sure if your provider (Endeavour?) gives you a similar web page.

Nope, nothing. AGL is the provider, but Endevour is the physical supplier.

[Andy Chee]

That's WAY too coincidental...
And on none of those days has my battery gotten to 20% and cut off. And you can see that exporting significant energy, biggest peak is 15.8kWh, which means my battery got full early and there was a ton of excess. Yet still I imported 1.38kWh on that day?

Do you have access to your energy provider's version of the same data?
For example, my energy provider (Jemena) has a website where I can login to get my interval data, like so:
Not sure if your provider (Endeavour?) gives you a similar web page.

Nope, nothing. AGL is the provider, but Endevour is the physical supplier.

AGL is also my biller, but Jemena is my physical supplier.

Not sure whether NSW is different to VIC in this respect, but I got my interval data through Jemena.

[Andy Chee]

Well that's inconvenient!

https://www.endeavourenergy.com.au/your-energy/your-electricity-meter/how-to-read-your-meter

How do I get access to my meter data?

Use our enquiry form to request your meter data. Or call us on 133 718.

Once you have contacted Endeavour Energy, we first need to verify you are entitled to receive the data using the information provided by your retailer.

[EEVblog]

Well that's inconvenient!
https://www.endeavourenergy.com.au/your-energy/your-electricity-meter/how-to-read-your-meter

Just filled it out.
"Data will be provided within 10 business days upon receipt of a valid request." 

[Someone]

Well that's inconvenient!
https://www.endeavourenergy.com.au/your-energy/your-electricity-meter/how-to-read-your-meter

Just filled it out.
"Data will be provided within 10 business days upon receipt of a valid request." 

At one point providers were only providing data begrudgingly, in spreadsheets for the specific requested period. No API or web interface. But it met their obligation to provide it.

[EEVblog]

At one point providers were only providing data begrudgingly, in spreadsheets for the specific requested period. No API or web interface. But it met their obligation to provide it.

That's what it sounds like, they have to do it due to regulation, but no mention is made of how easy it has to be. I expect to get a CSV file or something if I'm lucky.

[Njk]

BTW, it must be relatively easy for the utility (or for those operating the meters) to verify that the meter is located at the particular customer premises and is not stolen. That makes the utility well positioned not only to sell energy to subscribers but also to provide the client authentication service to interested parties.

E.g. the subscriber puts his private key to the meter (provided the meter will never leak it). Then, during a banking operation, for instance, the client sends a signed request to the bank that naturally wishes to verify the signature. To do so, the bank generates auth challenge message that also includes a one-time symmetric key, encrypts the message with the client's public key and sends it with the client ID to a known auth center where the utility is registered. The center identifies the utility to forward the message to. The utility, in turn, forwards it to the client's meter that can perform the verification as it possesses the client' private key. The meter, in the reverse way, communicates the response message encrypted with the symmetric key back to the bank. Something like this.

[coppice]

Is this an issue like the one described in another current thread, where the poor impulse response of the inverters allows substantial gulps of energy to be pulled from the grid to stabilise the local voltage? 2kWh per day seems a lot for that, but if some bursty appliances keep causing these gulps it doesn't seem impossible. Dave should attach a power quality analyser at the point of metering, and trace what is really happening moment by moment to the power flow. Unless he has disposed of it, he had a pretty nice Voltech analyser, as long as he has the necessary PC software to go with it It lacks its own graphing screen.

[tszaboo]

Is this an issue like the one described in another current thread, where the poor impulse response of the inverters allows substantial gulps of energy to be pulled from the grid to stabilise the local voltage? 2kWh per day seems a lot for that, but if some bursty appliances keep causing these gulps it doesn't seem impossible. Dave should attach a power quality analyser at the point of metering, and trace what is really happening moment by moment to the power flow. Unless he has disposed of it, he had a pretty nice Voltech analyser, as long as he has the necessary PC software to go with it It lacks its own graphing screen.

He has a CT for the house, he can double probe that.
It might be just an offset. But yes, 2KWh sounds like a lot, but it's only 360mA on the 30 or 50A or however much the connection is. So about 1% full scale.

[rteodor]

Maybe Deye has some setting like Victron does ?



50W setpoint amounts to about 1KWh / day.

Later edit: simple test: on a good day turn the breaker to the inverter off and see if that residual consumption is still there.

[EEVblog]

Maybe Deye has some setting like Victron does ?

(Attachment Link)

50W setpoint amounts to about 1KWh / day.

It does, set to 5W

[Siwastaja]

It might be just an offset. But yes, 2KWh sounds like a lot, but it's only 360mA on the 30 or 50A or however much the connection is. So about 1% full scale.

Can confirm. 2kWh/day = merely 83W. We sell a box which does battery control among other things and measures phase currents with those typical cheap Chinese CTs (like everyone else), and around 50-100W would be a typical offset number for our design, still less than 1% full scale.

Even if one developed a super accurate and expensive meter, it would still show an offset compared to the utility meter because those are not infinitely accurate either. Best is to get data integration with the utility meter (interfaces and their availability vary by country and grid company) because then you can feed the adjustment algorithm with the exact same data that gets used for billing - even if it's not completely accurate either. Our box has this option here, but inverters do not.

Or just accept there's going to be a small offset.

[Jeroen3]

Inverters have a maximum power ramp for grid code. How much is this in AU?

Those grid energy meters are supposed to be accurate up to 0. something %, that like a few hundred Wh per month deviation.

My money on the excess export is on dodgy software in the inverter. I mean, DEYE isn't known for the honesty. (see german scandal)

[rteodor]

My money on the excess export is on dodgy software in the inverter. I mean, DEYE isn't known for the honesty. (see german scandal)

I would think so too. If I watch grid consumption during the night when the mains is more quiet, that value swings from 20W to 80W all the time. During the day when more loads are coming and going from the grid that swing grows to like -30W (export!) to well over 100W.
Maybe Deye is built differently but regulation within 5W margin is not easy.

[Siwastaja]

I would think so too. If I watch grid consumption during the night when the mains is more quiet, that value swings from 20W to 80W all the time. During the day when more loads are coming and going from the grid that swing grows to like -30W (export!) to well over 100W.
Maybe Deye is built differently but regulation within 5W margin is not easy.

It's cheap electronics engineered to pinch the last penny, it's not like control accuracy of 1%FS or so is that bad - but it still feels wrong and causes real loss of money. The problem as I see is not the cheap-assery of these products in itself, but how much their price increase in the whole chain when you include sales, install work, etc, with each step marketing them more gloriously and adding their own profit, causing customer unhappiness over the price - quality ratio.