Logging consumption from solar pv input

Submitted by Aceshigh84 on Sat, 15/08/2015 - 20:51

Hi,

I've hooked up the emonpi and ct's as per the type 1 solar pv setup, I am getting an input from ct1 for grid, all good there.

The way my solar pv has been installed is as per the type 1 diagram, with the pv hooked up to a henley block along with the cables to consumer unit and grid.

However, I also have the solar pv generation meter and enphase unit connected to the same cable as the solar pv, and so at times when I am not generating, those two devices are actually consuming (like right now, it's dark, yet I'm measuring 7-10w on ct2). This consumption is shown on feeds value.

How can I configure the solar pv input to allow a negative value to account for times of no generation but consumption for the two devices?

Thanks in advance,
Colin

Re: Logging consumption from solar pv input

Submitted by Paul Reed on Sat, 15/08/2015 - 21:11.

This is a common issue, and probably caused by noise & other issues rather than actual consumption. These threads may help;

http://openenergymonitor.org/emon/node/10679

http://openenergymonitor.org/emon/node/10842

Paul

Re: Logging consumption from solar pv input

Submitted by Aceshigh84 on Sat, 15/08/2015 - 21:52.

Hi Paul,

Thank you for your reply, the links you provided explain why the solar value doesn't register below 10W on the solar app.

However, I know that there is consumption of approximately 7W on the solar "line", as the enphase gateway definitely consumes power and so is not considered noise. While this won't register on the solar app because it's less than 10W, it will register on the normal feed log and is incorrect as it's logged as generation.

I used to use Smappee and that would just register -7W (minus) when not generating, and then +xxxW when generating. I was expecting similar from OEM.

Cheers,
Colin

Re: Logging consumption from solar pv input

Submitted by Paul Reed on Sat, 15/08/2015 - 22:09.

If you are satisfied that inverter gateway is consuming 7W and you wish to record this as zero, why not add a 'process' to the solar feed, such as 'Calibration' '+' -7

That will always deduct 7W from your feed.

Paul

Re: Logging consumption from solar pv input

Submitted by Aceshigh84 on Sun, 16/08/2015 - 18:12.

Quick update...

I'd wired the ct's wrong, although I have a junction box, my system better matches the type 2 installation, as I don't have a single feed for "household" usage. So I have to calculate consumption.

At least now my figures are accurate with regards daytime generation, grid export and import.

I'll wait for the pv to stop generating and then see if it picks up the enphase envoy gateway electric consumption as a negative value.

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