With a 30 foot
boat, the effect of windage will be more of a factor too IMO. With
panels on arches and even folded down on the stanchions on the stern or the pushpit, you may notice more
weather helm to fight against. I only have a 100 watt panel, and mine is removeable and lives under a bunk if I am going to start sailing in more than 15 kts or so. But I have very
low power demands, a big
battery and I am usually anchored which gives me plenty of time to charge anyway. BTW watch out for those sharp corners... at least for me, every sharp corner eventually finds me... at the worst time.