Solar and a proper alternator with proper regulation on the main engine will produce all the power you need. Forget wind; very little practical yield. If you are crossing oceans or doing long ocean passages, a hydrogenerator can work. A portable suitcase
generator can be nice if you can't quite fit enough solar to provide everyday needs and you aren't running your main engine much (so you are anchored out for long periods at a time without moving).
With solar the more the better, but large solar installations are ugly and will have a negative effect on sailing ability of a monohull. You'll have to decide yourself how to balance these considerations.
But the good news is that it is fairly straightforward to make up solar power shortfalls with other power sources. It is really worthwhile to install a high output alternator, or even a second alternator if you have room for it, with external regulation. You can't get a lot of power out of a stock car-type alternator because these are not designed with the
cooling needed or the high temperature components for sustained high output use. A large frame
school bus type alternator is the gold standard, but if you can't fit one of those there are different sources for higher output alternators which can fit in place of any standard one, Mark Grasser and
Balmar, to name just two.
So very typical for a boat which needs more power than it can get from solar is to run the engine for an hour in the morning (or half an hour, or whatever) to get a good bulk charge on, then shut it off and let solar take over.
My previous boat had 800w of solar and we never really needed to do that. This more than covered all of our power needs. But the present boat is much more power intensive (washer, dryer, electric
cooking, etc.) and we use a heavy duty low speed diesel generator as the main power source.
Then you need adequate battery
storage. Forget AGM's and gels -- just use the cheapest 6v golf cart batteries you can find -- by far the best cost to value ratio of any batteries. The only other alternative worth considering is
LiFePo4, which requires a significant amount of installed infrastructure, so the intitial
installation may be expensive for a boat not designed for it, but which functions much better, lasts much longer, doesn't require all the maintenance, worrying about
charging up fully every few days at least, being left in partial state of charge, etc etc etc. There are some excellent threads on
LiFePo4 battery systems in this forum for further information.
Whatever type of batteries you choose, have enough. Lead batteries will give 50% of their nominal capacity in real amp hours from fully charge, and maybe 35% if short cycling. If you are relying primarily on solar, you will want to have at least a day's worth of your
consumption, as realistic stored power in the batteries, so you would want the nominal capacity of a lead battery bank to be equal to at least three times your average daily
consumption. If you have plenty of solar power, then lead batteries will be fine if there are enough of them. If you need to use other power sources, even if only as a supplement to solar, then LiFePo4 has some profound advantages (not a problem to never fully charge them, so no problem charging them opportunistically; high charge acceptance rate means possible to get maximum benefit from charging runs using internal combustion engines; others).
Have fun designing this; electrical systems on board are one of the more interesting subjects for cruisers, and it's satisfying when they work well. It's satisfying to go for months at a time off grid, producing and managing all your own power via a system you designed yourself.