Any way of adding template sensors?

[frsantos]

Hi

I have some sensors that need some processing before using it. For example, the version comes in a decimal number, but it should be displayed as V1.10.32, or there are some "total" measurements that should be the sum of the 3 phases (R,S,T) that come in 3 sensors each, or the total solar power comes from the sum of the 2 sensors each from a different solar string...

I'd like these to be defined in the inverter definition, instead of needing another template configuration outside. Can this be even possible with HA?