Hi all
This is my first post so please hang in there as I try to explain my issues ;-)
I am running a Grid Connected Solar install with no diversion so all excess is sold back to grid. I have a emontx v3 and emoncms 8 running on a pi with two ct clamps and an AC-AC 9v adaptor, our power here is 230v. I am trying to get the input feeds right so I can show four main things.
1. PV generation
2. Power usage
3. Energy sold back to grid
4. Energy purchased from grid
Currently I have CT1 setup on the solar PV cable and CT2 on the Grid meter side. I have included few screenshots to show what is not working. The last of the dials should be showing 0 as we are not importing any energy at present, but I am not sure where I have gone wrong.
Many thanks for the help.
Nathan
Re: Trying to figue out Solar with out energy diversion
Hi Nathan, welcome to oem.
To me it looks like your grid ct maybe inverted. The calculations are much easier if import is a positive figure,
that way solar + grid = consumption (so log all your solar feeds then consumption feeds on the solar input page)
and then use the grid input page to separate and log import and export using the allow positive and allow negatives
Paul
Re: Trying to figue out Solar with out energy diversion
Is CT1 going to Node 1, and CT2 to Node 2? Because it looks to me from your input list for 10:1 at the beginning that CT1 ought to be on the grid infeed and CT2 on the PV infeed, yet on line 13 of input 1 that treats CT2 as Grid; and on the input list for 10:2 the first log to feed is PV generated.
According to my understanding, and assuming positive is power generated and power imported:
PV generation is CT1 (pure & simple). It will go negative overnight as the inverter consumes some power in standby.
Power/Energy Sold is the negative part of CT2.
Power/Energy Purchased is the positive part of CT2.
Usage is (CT1 + CT2) It should never go negative.
Assuming CT1 is on the PV infeed and CT2 is on the Grid infeed, then this seems to do what you want (the basics only):
Input configuration: CT1
1 Log to feed - Generated
2 + input CT2
3 Log to feed - Use
Input configuration: CT2
1 Allow positive 0
2 Log to feed - Purchased
3 Allow negative 0
4 + input CT2
5 Allow negative 0
6 x -1
7 Log to feed - Sold
Re: Trying to figue out Solar with out energy diversion
Ok thanks, it is dark here in New Zealand at present so i have built up the feeds and will test the Ct orientation tomorrow. Many thanks for all the help.
Nathan
Re: Trying to figue out Solar with out energy diversion
Thanks so much guys, Changed the CT orientation and used Roberts design above and it works a treat. I have also now added kWh/d feeds and Histograms so I can make nice looking graphs to impress the ladies ;-) (Mrs Monk). The attached is a screen grab of a trickle of power first thing this morning.
Thanks again, it is all starting to make sense.
Nathan
Re: Trying to figue out Solar with out energy diversion
Thanks to Nathan and Robert I was able to finally get my PV monitoring dashboard up and running. Very happy with the results and most impressed with the ease of use (once you get your head around the relationships between inputs and feeds etc).
The daily bar graphs are a bit empty as this has only been running today.