Power requirements for an electric trike

[bemidjimac]

Hello,
I may be thinking out of my element here but I am considering a project. I want to build a recumbent trike that is electric powered. I want to take a slightly different approach however. I want to use the pedals to turn a generator to assist in the recharging of the batteries. Additionally, I want to add solar panels for additional recharging. With this set-up, I hope to significantly extend the range of the trike. Additionally, with the solar panels, charging can continue when the trike is not being used. What I am not familiar with is how to determine size generator and solar panels that need to be used. I want to build it using a 48 volt system. I am sure you will want more details, but I don't know what else to give you at this time (as I said, I am out of my element here but like to take on projects that stretch me).

Thanks
Ken

 

[CWatters]

How much power can the person pedalling produce and at what rpm? That's the size generator you need.

A lot of research has been done into pedal power. Not just for cycle racing but also man powered flight and for power generation in remote areas (lighting and radios in Africa).

Do some googling.

 

[Babadag]

Following CWatters recommendation I found this link in the web:
https://www.quora.com/What-is-the-average-pedaling-force-applied-by-a-bicycle-rider
From the above link P=300 W at 80 rpm.
You need some of this power to keep on cycling and another part to charge the battery.
So, let's say you have to climb a 15% slope hill , the weight of 100 kg and a rolling friction factor of
0.07 with a constant speed of 2 m/sec. The force will be 100*0.07*sin(a)=9.88 kg =97 N
[a=asin(0.15)] and the required power P=F*v=97*2=194 W.
The available power to charge the battery will be 300-194=106 W.
An average sun power [including efficiency] it could be 75 W/sqr.ft
It depends now how many hours you may dedicate for charge the battery.
A battery of 30 Ah will give 4.2 A /7 h [4.2*48=201 W].
Charging only by pedaling will take about 14 h. Combining pedaling and sun you need about 7 hours.

 

[CWatters]

This page says that tour de France cyclists average 250w cruising in the pack.

http://mapawatt.com/2009/07/19/bicycle-power-how-many-watts-can-you-produce

I suspect normal people would find that difficult to sustain?