[Shred]

I think there have been earlier threads on reducing power consumption for Tx units powered from solar panels, but I'm interested to see what people are currently doing.

My experience, so far has been:

1. Tx Arduino's Power LED disconnected
Result: Tx power reduced to 28mA from my 12v SLA battery with blips to >40mA on transmit

2. Replaced the 7809 with a more efficient Traco Power 1-2409
Result: Power use reduced to 21mA

The following SparkFun tutorial is pretty comprehensive:
https://learn.sparkfun.com/tutorials/red...onsumption

I guess the next step is to try disconnecting the USB interface, although "our" Tx units do not use the FT232RL chip. Using a switching regulator to supply 5v to the components on the Arduino board could be an interesting mod too.

A more difficult step would be to replace the 5v Arduino with a 3.3v unit, since the 3.3v Arduino appears to use significantly less power.

[werk_ag]

I guess the next step is to try disconnecting the USB interface, although "our" Tx units do not use the FT232RL chip. Using a switching regulator to supply 5v to the components on the Arduino board could be an interesting mod too.

And another one to supply 9V to the RF transmitter? Powered with just 5V its range is just a few meters.

A more difficult step would be to replace the 5v Arduino with a 3.3v unit, since the 3.3v Arduino appears to use significantly less power.

This one will not be so simple. It would imply significant changes on the code and a lot of work investigating the output voltage for each wind direction for the FO anemometers. There are still other possible problems.

Isn't more easier increasing the power of the solar panel a just few watts more?

[Shred]

And another one to supply 9V to the RF transmitter?

Yes - I'd keep the 9v regulator, since I need the range.

Isn't more easier increasing the power of the solar panel a just few watts more?

At the moment that's the approach I'm using. I have a 20w solar panel, but last Winter I noticed a big drop off in power produced. The problem is that I'm finding all sorts of other, non-weather related things that I'd like to run off the 12v supply in that area of the garden now and that leaves less power budget for the Tx. Maybe I'll have to buy a 30w panel next Winter.