Frank, give us your scenario. Solar can be an expensive initial outlay for the right setup. What boat? how many batteries? Location boat is at? Any existing power for use? Security at location? In a slip? Do you want this as your primary means for recharging batteries etc? There is a lot of factors to consider. Oh and welcome to the forums. I moved your last post here so you can get specific answers to your question so it wouldn't interfere with the original posters thread.
Now me, if there's ANY power, I'm going to use onboard chargers (NOCO has become my favorite). I have used solar panels but on a very small scale, it was more for trickle charging/keeping the battery topped off at docks or even while traveling. I think it was only a little 5amp at most. The bigger ones have to have other configurations and a means to regulate voltage so as to prevent overcharging etc. That can get up into big bucks, BUT if there's no power available, then its the only way to go.
When I worked IT in the Colorado area, we equipped remote shacks with batteries and a radio that would convert to ethernet (it was equivalent to 4 T1 lines, so it handled phone call relays as well as ethernet) so we could monitor levels in brown water tanks so we could dispatch trucks when needed up the mountain areas to haul the water off. Did fine except during heavy snow, then we'd have to send a team to shovel off the snow if no signal came on for 2 days (batteries would hold power for 4 days without solar). Not cheap though for the initial outlay.