Using a spinning chimney cowl?

Hey Permies! I live in a historical area of Italy and can't put up a windmill due to local visual codes. But everyone has those spinning chimney cowls. Wondering: can I attach a spinning cowl to a horizontal bicycle wheel and use a bike-lite generator to charge a battery? Do they generate enough power? Ever hear of anyone trying this? Thanks!!

Hi Jack. Welcome to permies.

In theory it will work. That is essentially a vertical axis turbine. Anything that keeps the generator spinning within it's normal operating rpm range will work. YouTube has many examples of bicycle wheel turbines.

There are 6 volt & 12 volt bicycle generators so that needs to be considered when selecting batteries to be charged. I wouldn't expect to be cooking many meals from this system but it could work well for running some low power devices like LED lights or charging AA's & AAA's. Might want to consider adding a small charge controller.

Welcome to Permies Jack!  I'm sure you could generate some electricity that way.  I'm guessing you could generate much more with a purpose built vertical axis wind turbine that is designed to look like a chimney cowl.  Maybe also a little bigger than a standard cowl but not so much bigger that people notice.  

It would amaze me if it could, chimney cowls are super light, normal wind won't turn the wheel, and if you add the bike dynamo the friction will be too much. It will stand still. They are expensive and fragile. I've removed one that made a squeeky noise every turn. Better buy a small solar panel, Italy gets a lot of sun hours.

Dug up some battery & bike generator specs online & did some quick calculations. Assuming there is enough wind. Guessing 10 - 20 kph minimum.

It will take 40 hours to charge a typical motorcycle battery & 100 hours to charge a typical car battery. That assumes no losses & perfect generator operation. So figure double that amount of time in the real world.

A fully charged heavy duty marine battery (bigger than the car battery calculated) will cook a thick hamburger on a hot plate before it needs recharging. Or barely boil enough water for 2 servings of rice. That should give some realistic idea of what to expect.

The idea has some merit. Especially in a place with rules & good wind. Would be a fun project but don't expect miracles. As already mentioned ... there are obstacles & quite possibly better alternatives.

Great comments, All. Thank you! Yeah, I'm a former off-the-gridder and looking for a project. Solar panels are not allowed unless you're super discreet or your Uncle Vito "knows a guy!" Just looking to power some LEDS so I don't break my neck on one of our four flights of stairs!

Jack Thomas wrote:Hey Permies! I live in a historical area of Italy and can't put up a windmill due to local visual codes. But everyone has those spinning chimney cowls. Wondering: can I attach a spinning cowl to a horizontal bicycle wheel and use a bike-lite generator to charge a battery? Do they generate enough power? Ever hear of anyone trying this? Thanks!!

I read about a horizontal stealth wind generator that went along the roof ridge and appeared to be part of the roof. The person lived in a neighborhood with a lot of regulations about how things should look. I don't remember where I saw this but maybe if you research stealth wind generators you will find it.

Here you go just what you need)  https://newatlas.com/secret-energy-wind-turbine/14299/  looks like a chimney cap and is near silent.  
Otherwise put a movable solar panel inside the house when the sun is shining thru the window.