Setting up emonpi with mulitple solar inverters. How best to create feeds

[nchaveiro (Chaveiro)]

There is a good topic about virtual feeds on the old forum:
https://openenergymonitor.org/emon/node/10977

And a nice starting thread here:

Understanding Virtual Feeds

When do you need to make use of a virtual feed vs doing processing with input and storing the value in a feed? I would like to calculate when solar generation goes above 2.5kW. I can program this with processing from the input, so that a 1 is stored in the feed. Is this a correct implementation? Or should I make use of a virtual feed? What are typical use cases for virtual feeds? Could data of virtual feeds be extracted in an automated way to be used in another application?