Current Cost Support Forum

Good morning everyone,

I tried to monitor with ENVI monitor the production of the my 3 kW photovoltaic system, but I am a little puzzled with the result.

After connecting the monitor with an ENVI a normal trasmitter near line output of my SMA Sunny Boy, I found that the energy measured was about 20% lower than the value indicated by the inverter. In practice ENVI monitor shows quite less energy than does the inverter.
I also tried a second monitor ENVI and then with a second transmitter, but the result was the same. So there seems no to be an individual device defect ENVI.

At that point I also came to suspect that it was also approximate the normal reading of energy under power meter (grid), that is the normal way of use of ENVI monitor. But then I checked with another portable power meter and I realized that is not wrong in this way.
Why I find this difference in size with Photovoltaic energy line?
Is there anyone who has tried and tested such a thing?
Thanks, Pasquale

The envi clamp can only measure the current flow but your portable energy meter and the display on the inverter probably display true AC power.

To obtain a true AC power reading the meter needs to know the voltage, the current and the power factor of the load.

PV inverters also often appear to draw large amounts of power during the night when monitored with clamp devices.

This is because they have large capacitors on the AC side which don't actually use any power (other than very small leakage / safety discharge circuit) but can draw a large current, sometimes registering over 100 watts (depending upon inverter size).

What we need is the Current Cost "Pro Range" with sensors that read the AC mains voltage and with this they could also check the power factor.

With the transmitters mains powered, data could be transmitted to the display units more often.

Automan.

I suspect it is time that CC offer a energy meter range for the more professional user who requires accuracy and better integration with other energy sources.

mycurrentcost.com for example is quite basic, only offers a single channel and does not seem to support a positive energy flow rather than negative.

Such a "pro range" I imagine would cost a little more but for those who have invested in PV projects or other alternate power sources e.g. EcoGen gas boilers such a product range would be useful.

Automan.

Hi,

I also have my Envir set up to monitor my consumption as well as PV production, and the PV production is out by about 50%! This is compared to what the inverter claims it is putting out (2kW Aurora). I know the consumption readings are pretty good (within 5%) as I've been checking them with the electricity meter and known lighting loads.

So I waited for usage to plateau and clear blue sky, then swapped the plugs of the two transmitters. Sure enough the PV increased by about 2X and the usage went down.

I suspect a faulty CT sensor clamp for my set-up, not sure how to return it though.

Hi matchfairy

If you look at the main currentcost.com site there is a contact us button. From there you can contact Technical Support. I find that the response from them is usually pretty quick for returning items if they are faulty.

Hi,

I use the smaller pincer style CT sensor to monitor my consumption and PV generation. Interestingly an old Electrisave (cent-a-meter) seems to record the generation as zero at night, whilst the EnviR device reports a steady 45watts each night.

I am wondering if changing to the mini style clamp would make any difference or if this difference is fundamentally down to a difference in the way the two units work?

Has anyone tried these?

I have finally replaced the suspected faulty CT clamp on my solar AC active. It is now tracking the reported inverter output nicely