Something does not add up..

[Uklad]

Hope your guys can help with this had my 4 kWh system in since Dec 18 2012 everything is working great but i have just entered my import meter reading onto Scottish Powers site and i don't seem to be seeing much of a reduction in my ele usage

Feb usage = 369 vs generation 142 kWh export measured at 50 kWh
March usage = 366 vs generation 271 kWh export measured at 80 kWh missing a week of data..

I have noticed when i do meter readings at the end of the month the import meter is always showing rEd

 

[Gary K]

rEd stands for reverse energy detected. some meters can be configured to add any energy going the wrong way through it to the used energy reading- it to stop people frauduantly rewiring their meter.
Obviously if you don't use the energy as it is produced, say you are not at home during the day so no usage, then you will not save anything. once it is exported then its gone.

 

[Uklad]

Ahh so my export could be being added to the import meter who fixes that for me ?

 

[Earthstore]

Your energy supplier should arrange for a meter change/upgrade.

 

[whinmoor]

Is your import meter a Siemens?

Or, do you have a pre-payment meter?

 

[liquidity]

But just because it's saying rEd doesn't mean the export is being added to the import.

You give what appear to be import, generation and export figures for Feb and March. Where does the export figure come from?

 

[Uklad]

From my owl PV system everything else is from meter readings

 

[Gavin A]

Is your import meter a Siemens?

This is an important question.

There's an entire batch of siemens meters out there from around 10 years ago that have an anti-tamper setting that means they read both import and export as if they were both import, which would explain your readings.

There may also be other makes with the same issue, but I've not come across them (yet).

 

[FB.]

But just because it's saying rEd doesn't mean the export is being added to the import.

Agreed - I have a Landis&Gyr E110 electricity meter an although it says "rEd" it does not add export to import (neither does it go backwards like the old mechanical meters).

By chance my solar array also happens to have a Landis&Gyr E110 to measure export.


As some people have suggested: perhaps the power generated by the solar is not being efficiently used ("use it or lose it"), but on the other hand some people with solar over-estimate how much it produces and switch everything on (sometimes in a wasteful way), resulting in a lot of power being imported from the grid because the power demands are so high that the solar can only provide a small portion of it.

At the moment, I'm generating about 0.6kW (3.7kW solar array) on a "white cloud" afternoon. My computer is running (0.2kW), the central heating is running (0.2kW for pump/fan etc), my wife is watching TV in the other room (0.2kW) so we're using all it's producing. We just boiled the kettle (3kW) so during that time we were still having to import 3kW of power for five minutes. Not to mention if we were running the washing machine, power tools/garden tools etc.

 

[Uklad]

The generation meter is a Landis&Gyr E110 my import is a Ampy Automation 5235a looks the same

 

[SibertSolar]

They're both effectively the same meter. Your primary/utility/import meter shows rED when reverse (exported) energy is sent to the grid, as others have said. Your system is most probably exporting energy when you need it the least, thus impacting on your imported values very little. You need to store or be smart about how you consume your generated energy if at all possible, in order to reduce your net import.

Just as an aside, how accurate do you believe your Owl monitor to be? I've seen over 20% innacuracy on some systems...

 

[Uklad]

Today my owl has measured 12.1 kWh generated from CT clamps, PVoutput logged from the inverter is showing 12.5 kWh that's a 1% difference in my calculations are correct

Helmshore sun trap ! 4.000kW

I'm not really questioning the smartness of my energy usage, im just not really seeing the difference in my import meter that i would expect based on my generation, maybe it is just me meter configured wrong..

 

[FB.]

I'm not really questioning the smartness of my energy usage, im just not really seeing the difference in my import meter that i would expect based on my generation, maybe it is just me meter configured wrong..

Is your house a high consumer of electricity, and the cold weather has caused you to use more? It is reckoned that gas usage is up by one-third on last year. Quite a few people are looking at their gas and electric meter in recent days (bills due soon) and a lot of people have had a fright at just how much they've had to use to keep warm this winter.
So if you have quite a lot of electric heating in your house, maybe the bitterly cold weather has caused higher usage than last year, but the solar has made a contribution which has kept the electric import about the same.

 

[Uklad]

Ha Ha don`t mention the gas bill holly carp !! with this winter and an extension added to the house in the summer the gas has shot up, i think i will give it another month and do some calculations again and see how it goes

 

[Worcester]

The other thing to consider is that occasionally some installers have incorrectly connected the PV to the WRONG side of the consumers meter, so you're not getting the benefit of anything you generate (except the FiT).

How is your's wired in - a photo would help us and save a dozen posts asking for more detail.

 

[danesol]

Today my owl has measured 12.1 kWh generated from CT clamps, PVoutput logged from the inverter is showing 12.5 kWh that's a 1% difference in my calculations are correct

Helmshore sun trap ! 4.000kW

I'm not really questioning the smartness of my energy usage, im just not really seeing the difference in my import meter that i would expect based on my generation, maybe it is just me meter configured wrong..

Does your OWL work out what your actual export values are ??

As looking at your PVO account - they either arent posted or you have PVO settings set incorrectly ??

As said above - you wont see a great reduction in your electrical bills Jan-Feb and Nov-Dec, especially if your export percentage is high as well.

 

[danesol]

Hope you dont mind, but another observation just looking at your LIVE data - your voltage seems to go a little high - you may have to keep an eye on that when the production really kicks in, as your Inverter may start to shutdown if it gets too high.... assuming that (grid) voltage figure is accurate btw


ps> where is that Temperature value coming from too ??

hth

 

[Uklad]

The data on the PVO is direct from the inverter the TEMP is the inverter temp i think, i can not find a way to link the owl data into PVO.. so the export is just the same as generated.

on a side note about the grid voltage i have noticed its a bit high but for a few days in feb is dropped but came back up

Helmshore sun trap ! 4.000kW | Live Output

Is there anything that can be done about the high voltage

 

[danesol]

The data on the PVO is direct from the inverter the TEMP is the inverter temp i think, i can not find a way to link the owl data into PVO.. so the export is just the same as generated.

on a side note about the grid voltage i have noticed its a bit high but for a few days in feb is dropped but came back up

Helmshore sun trap ! 4.000kW | Live Output

Is there anything that can be done about the high voltage

Well as long as it isn't ambient temperature around the Inverter you are OK

With regards Grid Voltage, just keep an eye on it as it may cause an issue when fully generating, are there any other Solar PV arrays in your surrounding area that you know of on the same sub-station ??

If you do have issues - May onwards, you or your installer could try speaking with your DNO about lowering the grid a wee bit, as I personally found my DNO very helpful when I reported that voltage was too low in our road on every phase ( 216Vac ), however I suppose it did cost them a fortune in my repair bills so may have been over obliging in my case switching the network within 3hrs of the callout ( after checking other random houses in the road on each phase ) but are not obliged to do anything unless its outside std +/- tolerances.

 

[Uklad]

I know of 1 other system that is on the same sub station looks in the region of a 2kWh, i have long had issue with halogens popping way to soon and LED transformers not lasting long..