you can install an emoncms server locally without contact to the emoncms.org website.
guess you can run pimatic and the emoncms server on one pi, maybe the pi2 would be the better choice for that.
BUT in deed the emoncms.org website is not needed at all.
if you are using the pcb from lechacal (or maybe having your diy circuit with this sketch), you can change the attiny sketch and write the readings from the sensors in clear text instead emon formatted. then you do not need the emoncms server at all. then you can read the sensor values every X seconds to a logfile via cronjob for example and read this log with a logreader device.
const boolean OUTPUT_AS_CSV = false;
const boolean OUTPUT_AS_CSV = true;
here’s the sketch:
Guess I will change my setup in the near future to this solution to reduce some LAN traffic.
hope this helps!