Thanks for clarifying, Bushman !
As I understood, once you use Meteobridge, you cannot use e.g. Cumulus anymore. I think it is easier for a newbie like me to have the choice between several software packages instead of being forced to use one particular. And I have more than enough webspace available, so that is not a problem, either.
Meteobridge has indeed the advantage of being very low-cost on energy (about 2 Watts as you mentionned), but I think using a weather PC gives more flexibility for the user. After all, the mini PC I found is sold for 40 euro (about 54 US $), and a power consumption of 30 Watts means about 0.20 US $ per day, so that will not make a big difference on the electricity bill here.
I will give it a try and see what it means in reality
Thanks for your replies !
Ronny