How much power could a person regenerate?

Hello dear fellow ebikers, I'm investigating the possibility of the usage of a hub motor to generate electricity for a fun project.
I was thinking of using a bike with a rear wheel direct drive motor, with the wheel lifted off the ground, to be able to generate electricity by pedaling. The generated electricity I want to use to do "fun" stuff like light and sound effects and that kind of things.
So, I'm trying to find out what comes out of a regenerating direct drive motor, and how to make use of it.
I imagine that the voltage coming out will depend on the rotation speed and the current will depend on "how hard it is braking" and that I would need some regulating electronics to be able to make it usable.

So, I decided to post here, in the hopes that some of you would share your wisdom and thoughts about this matter.

Thanks in advance for your replies.

Above 1200W burst for some professional or olympic cyclist...
About 200-300W for a great healty cyclist
About 100W for a not motivated of pedaling
About 75W for a lazy cyclist

An average human body dissipate about the equivalent energy in heat of a 100w bulb.. but that energy is difficult to recover...


327w continuous average power for an awsome cyclist:




a good exemple:

[youtube]S4O5voOCqAQ[/youtube]

That was a great reply! Robert made my day,thank you.

knutselmaaster said:

I was thinking of using a bike with a rear wheel direct drive motor, with the wheel lifted off the ground, to be able to generate electricity by pedaling. The generated electricity I want to use to do "fun" stuff like light and sound effects and that kind of things.

Click to expand...

This has been done many times by many people and works just great. In it's simplest form, you use a 3phase rectifier on the motor outout (a normal ebike controller will do the job just fine), and choose a motor KV and gear ratio such that at a normal pedal cadence the generated voltage from the motor is of the same order as the battery voltage that that you are using as a charge buffer. Then as you pedal harder and harder you'll get more and more current flowing into the pack, but your overall pedal rpm won't increase too much. When you pedal speed is below that required to produce enough voltage to charge the pack, then there is no pedal resistance from the hub. Rock the bike in Oakland CA have built an entire business around this:
http://rockthebike.com/store/

As a more advanced approach is to use a motor controller with regenerative braking on it, and then you can dial in the amount of pedal resistance independantly of your pedal RPM, and you don't care as much about the specific KV of the motor and gear ratio matching your battery voltage. The motor can be generating a lower voltage and the regen capable controller will step this up to the system bus voltage.

As Doctrobass said, expect ~100 watts form someone just sitting there pedaling away, and a couple hundred watts from people who are sweating it. If you ever sit on an exercise bike at the gym most of those have an option do display your wattage output. That is the mechanical power your legs are putting on the cranks, expect the electrical power you get for running accessories to be 75-85% of this depending on the generator efficiency at that particular load and RPM.

Meanwhile, Brazilian prisons have also adapted this concept. No need to stick to a direct drive hub motor either..

https://www.youtube.com/watch?v=VSMKGMcgDec

Yes, this is what I was thinking of - a car alternator (cheap from a wreakers or just find someone parting something out). Pretty straightforward if 12v is the ticket... theres a bunch of youtube videos of people doing it.

https://www.youtube.com/watch?v=cn_Pi2GpBMs

Those are very informative replies, thank you.
Using a car alternator is not bad as an idea, as I would surely use 12v appliances and it certainly is the least expensive solution. The hub solution is a lot cleaner and "ebike-ish" though.
A lot of stuff to think about, it is always great to have different people's opinions on projects before starting to build

My human power generator:
https://www.youtube.com/watch?v=cuVjm5RWtwk

justin_le said:

knutselmaaster said:

I was thinking of using a bike with a rear wheel direct drive motor, with the wheel lifted off the ground, to be able to generate electricity by pedaling. The generated electricity I want to use to do "fun" stuff like light and sound effects and that kind of things.

Click to expand...

This has been done many times by many people and works just great.

...

As a more advanced approach is to use a motor controller with regenerative braking on it

...

That is the mechanical power your legs are putting on the cranks, expect the electrical power you get for running accessories to be 75-85% of this depending on the generator efficiency at that particular load and RPM.

Click to expand...

I have a Phaserunner and CA and 48V battery - what is the better motor to use for this?

Geared or direct?

If direct, fast-wind or slow-wind?

You folks might find this little ABC news item of interest:

Newport Folk Festival includes stage powered by bicycles
https://abcnews.go.com/Entertainment/wireStory/newport-folk-festival-includes-stage-powered-bicycles-87289915

"The Newport Folk Festival is known for creating electrifying musical moments, and this weekend it is powering a small stage in part by festival-goers on stationary bikes"