"Up to 16 watts" doesn't mean you'll get that at normal speeds. The drag is 6 watts at 20 kpm powering a 3 watt light. Google "Schmidt son bicycle quarterly" for more info. How much riding power do you want to direct to not moving?
Check the following too.
http://www.peterwhitecycles.com/pedalpowerplus.asp
Last edited by njkayaker; 04-16-13 at 07:31 PM.