Why do I have to measure the Solar Panels?
When you have Solar Panels, you should measure them! When your Panels produce energy, that energy will first flow into your home's appliances. Only the excess energy produced will flow back to the grid, via your energy meter.
If you would only measure the total current from the grid, then Smappee would not be able to make the difference between a Power reduction of e.g. -500W, by measuring that the total power from the grid has been reduced from e.g. 2000W to 1500W (-500W) due to your the Solar Panels that suddenly produce an extra 500W (means you will need less from the grid as the panels produce the 500W now) or due to an appliance of 500W that just switched Off (you consume less, so you will take less from the grid).
Where to install the CT's of my Solar Panels?
In the following picture, your Solar Panels are connecting behind the main Fuse. The current flowing through the main CT's (Current Transformers: Smappee's Current Sensors) that will measure the net energy that will flow from your meter to your house.
CT's on the wire from your energy meter into your fuse panel will measure the
Grid = Consumption - Production
The CT's on the the wire from your Solar Production will measure your Production.
Without CT's on the cables feeding the Solar Production into your panel, you would not be able to measure your Consumption exactly as:
Consumption = Production + Grid
Grid metering, this is the default configuration of Smappee, position the CT's here:
Other configurations are possible as wel, e.g. Load metering:
Change advanced metering and CT configuration parameters in Smappee's Web portal. More on this, here.