Like some others I have really good charging sources while away from the dock. Large capacity alternator on one of the engines, and a nice NL 9kw generator.
My boat also uses between 35 and 40 amps of DC pretty continuously, even though I have LED lighting. Lots of stuff on the boat, and I do not desire making any lifestyle sacrifices
What that means is that I am using around 840 amp hours a day or around 10 KWH. This is not including the electric stove, or the watermaker, washer drier, things that cannot run off of the inverter.
I was thinking of adding two 160W solar panels, but I’m rethinking that. Using the 30 AH per 100W number thrown out there in this thread This setup would provide around a hundred AH per day for probably 6 months or so, but no more than that.
While cruising that might reduce my generator run time by an hour a day at the most but probably not, and while at the dock it might reduce my power bill by $10 per month but only if I capture the entire output, which will not necessarily happen since my boat is plugged into shore power all the time.
For me the approx $1000 investment would not only never pay for itself, it wouldn’t help reduce my dependency on generator power either.
Personally guys I like my generator. It is so quiet you cannot hear it, it is reliable, and it produces enough energy to live my life at sea without compromising anything.