Originally Posted by
noglider
JohnJ80 exactly. People see dynamo hubs and think, "great, free power" until they do the math. I don't feel my dynamo hub's drag, but I'm only powering two lights. If it gave 10w of electrical power, I'm sure I would feel it, and it would probably be objectionable.
I looked at this further and a 20W solar panel can be had for about $75 and would probably do a lot better in providing more power. It’s probably weight neutral to the dynamo hub but even if it’s not, the watts used in pulling the additional 500g (panel i was looking at) would be largely negligible.
I generally think 27Wh would more than suffice for what I need for two of us per day and the solar panel could do this in under three hours at half it’s rated capacity.