Andy Burns has brought this to us :
Which is odd, I assume your meters work similarly to mine, the gas one being
battery powered and sending its readings over low powered radio to the
electricity meter, which is mains powered and forwards electricity and gas
readings to the in-house display and for billing via a GSM network.

Well, that was what I too thought, but maybe not.

The G SM reports through to the display every few minutes, the E SM
every few seconds.