Wirelss energy monitor for PV system

[dougalthedog]

Hi,

There are plenty of energy monitors on the market at very reasonable prices (<£50) and we have been supplying these to allow customers to easily monitor how much they are generating. Is anyone aware of a device with 2 separate clamps / readings which would allow the user to view how much they are generating / using / exporting on one display?

Thanks.

 

[SolarCity]

The Wattson should do it. If you can get one that works.

 

[dougalthedog]

Looks good - are they problematic? Do you have to buy an extra clamp separately to monitor generation and consumption?

 

[SolarCity]

The solar specific model has two clamps.

Are they problematic? I don't believe so. I have bought one and it doesn't work - technical weren't entirely useful. It sounds like I may have just been unlucky.

 

[saint]

did you come to a conclusion as to whether you have to have a separate cu for the PV?
I have seen comments on another thread but no real conclusion ????

 

[SolarCity]

I think that you probably do if you want to get accurate readings.

You need to be able to monitor energy usage independently of the PV system - which you can't do if the PV system is connected to the same CU.

 

[dougalthedog]

In theory it's possible to do it without a seperate CU I guess - import (or export if negative) = consumption - generation so as long as you measure generation at the cable from inverter to CU and total flow into / out of the CU / meter it would be fairly simple arithmetic to calculate import, consumption & generation. However, the device would need to have different modes depending on how / where the two clamps are postioned - I'm off to consult the manuals and see if they mention anything.