Marno...how many amp hours of power per day do you need and what kind of space do you have for panels
? As a rule
of thumb...divide panel wattage by 3 to determine how many amp hours you will get from them on a sunny day.
Example...if you need 50AH's per day on board...get 150+ watt solar panels
Most 12V large panels put out around 17V-18V in bright sunlight and need a controller or regulator
if you don't want to burn out your batteries.
A good Mppt
controller/regulator will help this a bit. My guess is solar
is a less good idea where you are than in most places! (G)