I don’t yet have the emonTH but not to sure it can ‘stock’ data locally, you have to let emonhub active.
Basically it takes measures and sends data directly to emonpi or emonbase …
Guess you’ll have to keep the pi running 24/24 7/7
taken from the shop description
Data from the emonTH is transmitted via wireless RF (433MHz) to an emonPi / emonBase web-connected base-station for logging to Emoncms for data logging, processing and graphing.
As far as I know, no data is retained in the emonTH (or emonTx for that matter - except for the “…ACK” sketches which retain it until receipt is acknowledged or the number of retries allowed is exceeded). It is transmitted immediately it has been collected and if the transmission fails, it is lost.
I did not expect the emonTH to retain data whilst the pi was off, The problem was that when I turned the pi back on this morning, it was not receiving any current transmissions from the TH.
Incidentally, after power cycling the Pi a few times, it has started working again.