The summary.
RADIO TRANSMISSION DOMINATES POWER CONSUMPTION
Reducing transmissions extends life more than any other change. The device should sleep almost always.
Measure actual consumption with an instrument — estimates omit leakage, peripherals left enabled and unexpected wake-ups.
A DEVICE IN POOR COVERAGE MAY CONSUME SEVERAL TIMES MORE THAN ONE IN GOOD COVERAGE
Because of radio retries. Signal quality is a power question, not only a connectivity one.
SIZE SOLAR FOR THE WORST PERIOD, NOT THE AVERAGE
And account for dust on panels, which substantially reduces output here.
Mains-powered devices must survive routine outages and resume automatically — nobody will visit to restart them.
INTERNAL TEMPERATURE IN DIRECT SUN FAR EXCEEDS AMBIENT
And metal enclosures block radio almost entirely. Both are discovered late if not checked.
VERIFY THE DEVICE WORKS BEFORE THE INSTALLER LEAVES
Returning to fix an installation costs more than the device. Record identifier, location, photographs and signal quality at install.
RUN A PILOT ACROSS A SEASON AND MEASURE SUPPORT EFFORT PER DEVICE
It determines whether the deployment scales economically.
