Strange meter readings

[BroT]

I started work at my current firm 6 months ago and a customer has just phoned through saying that their IMPORT meter and elec bill has rocketed up since the PV was installed last summer. Can anyone think of a situation where the electrician could have wired the system that would cause these results? Spoken to a few mates who can't think how this could be happening. Here is his most recent email

"Hope all well, I need your expert help here, previous year before we installed solar penals our electric consumtion was around 1855 units now last 8 months it shoot up to 3156 units, we have produce 1000 units from the solar penals, we havnt bought any appliances which burn more electricity, not sure whats happening.
Southern electric has no clue about this problem.
please help me out here.
kind regards"

Any ideas?
Tim

 

[ktech]

Some utility meters can increment when exporting. I did find a list of meter types once but it didn't seem definative. You could suggest the customer waits for a good sunny day and have little load switched on , ie. they should be exporting. Then check the utility meter each hour and see if it is still going up.

 

[FB.]

Quite a few people seem to think that having solar panels means they can use all their appliances on full power all day long, without drawing power from the grid.

But 1855 + 1000 = 2855 which is not too far off 3156. So could be that the meter is adding-up power flowing in both directions.
I'd do as ktech says; during a sunny spell, turn off everything in the house and see if the import meter creeps up by the same amount as the generation/export meter.

 

[Ian-LS]

What type of meter is it? If its certain type of Siemens meter then it does the opposite to disc meters and PV increases the meter readings rather than reducing them.

 

[LightGEN]

The Landys & gyr (Ampey) model 5235 is quite widely used and this can be configured in "Unidirectional Register" mode, which sums import and export energy in the same register. If the meter is configured as such, it will display a lower case letter 't' on the digital display before the meter reading. The meter owner can reconfigure the meter, via the IEC1107 port, to change the way it deals with exported energy.
I have one of these meters on my own property and in, this case, the meter is configured to cycle between an import and an export reading every few seconds. The other option for this model of meter is that it cycles between an import reading and displaying 'rED' (reverse Energy Detection), an indicator that the meter has measured reverse current flow in excess of a programable threshold.

Regardless of the meter type, call the electricity supplier and get them to reconfigure/replace the meter and deal with the over-charging.

 

[empower]

As others have said, get the meter swapped out with a modern one asap. Something with separate import/export registers! Will need to go through your utility company i'm afraid.

 

[LightGEN]

<snip< get the meter swapped out with a modern one asap. Something with separate import/export registers! Will need to go through your utility company i'm afraid. </snip>

The meter sounds like it's already a 'modern' digital one. I wouldn't be surprised to find that the utility just reconfigures the meter to display in bi-directional mode.
In fact....thinking this through some more, it's possible that the meter has the export data stored in the export register and that reconfiguring the meter will cause the meter to correctly display seperate import/export amounts. I'd be interested to know if this is the case.

 

[empower]

The meter sounds like it's already a 'modern' digital one. I wouldn't be surprised to find that the utility just reconfigures the meter to display in bi-directional mode.
In fact....thinking this through some more, it's possible that the meter has the export data stored in the export register and that reconfiguring the meter will cause the meter to correctly display seperate import/export amounts. I'd be interested to know if this is the case.

All because it has a digital display does not necessarily mean there are separate registers for import and export. Some really 'dumb' meters are single energy flow meters with an LCD and some tariff programmability. Having said that, i've never heard of a meter that accumulates import and export into a single reading, doesn't even sound legal. Maybe the meter is just faulty. Will have to wait to see what the OP says.

 

[SibertSolar]

There are several meters that can accumulate import and export energy measurements into a single display register, it's not that unusual - just doesn't necessarily make sense to "us" when we consider the self-generation/FiT model requirements.

 

[LightGEN]

'Unidirectional register mode' is a fraud prevention feature - the meter continues to count upwards if the 'customer' re-wires the meter for reverse flow.

 

[Meterman]

Hi Bor T

Sounds like your meter is advancing when you are exporting to the grid.
Contact your supplier and tell them you have had solar panels installed and you think that your meter is advancing when you are exporting to the grid, they will come and fix / replace your meter free of charge.

 

[dansk]

Before phoning the utility company, just double check the PV is not connected before the import meter by the means of a henly block, this was the culprit the other week on a job posted on this forum, its not always the meter at fault.

 

[mcantwel]

I had my main electric meter replaced mid February as it was deemed to be too old. On the old one, I could tell if the PV was feeding into the grid by the normal energy usage light being solid on instead of flashing and a "RED" (Reverse Energy Detected) LCD indication. However, my new Sagemcom CX 1000-3 CLK does not appear to give any such indication. Is anyone able to advise if this meter is compatible with a PV system?
I do not myself benefit from the Feed In Tariff as this is gained by the PV system supplier but I do expect gain from free electric when its generating and hence, the meter is not incrementing.
I checked yesterday (the sunnies day of the year so far) and my PV was generating 2 to 2.5kW (and no clouds to diminish this) and I had nothing but fish tank and fridge/freezer on yet I consumed units* in a 2 hour period. This was definitely not the case with the old electric meter.
Note * What 'units' does the new meter measure in, surely not kWh since I have consumed 2561 since its installation which is more than 4 months over the preceding Winter period!

 

[SolarCity]

It is possible that you have consumed 2,561kWh but only you will know if this is consistent with your usual energy usage. As for the meter, I have no experience of that model. However, there is an easy way to test to see if everything is working as it should. Switch everything off in your home at the consumer unit apart from your PV system (as long as you keep the doors shut on your fridge and freezer, they should be fine). Leave it like this for a few hours and then check to see what has happened with the meter. If it has accumulated units then it is possible (although highly unlikely, seeing as it's a new meter) that is registering units being fed back into the grid as units being consumed. This can happen with some meters but it would be surprising if the meter was recently replaced with a model with that 'feature'.

 

[liquidity]

A quick search on that meter suggests it has an export counter/register. Are possibly there any buttons on the front that you can push to scroll through the import and export registers?