The most logical thing to do is
an energy budget, which will most likely tell you that the best first thing to do is increase your house bank capacity.Then, and only then, you can go figure out what else you can do to supplement your engine charging system, like:higher output alternator and smart regulator (got a stock OEM alternator? - you'll find out soon it isn't worth much)solarsmall generator (gen set)windetc.StuPS "windmills" are generally the LAST thing people add. Catalina builds great boats (congratulations on yours!) but leave a LOT to be desired on the electrical side, especially battery banks and alternator charging. We can't seem to get Gerry to do anything about it, because most people don't know enough, or won't pay extra for it, because they don't know until they get and use the boat. The factory has thrown some crazy switching into the electrical loop on some of their newer boats, but a small, inadequate house bank with a stock internally regulated alternator will let you down every time. If you don't have it already, buy Nigel Calder's Boatowner's Mech and Elect Manual. I had a C22 for 3 years and a C25 for 11 years before we bought our C34 in 1998, and that book saved me tons of problems. The first chapter alone will answer your question. The best $50 you'll ever spend.