How to make a home-made Hydro-Electric generator?

[pjl83]

Hi All,

 

My nephew has been learning about Hydro Electricity at school. He is very interested in the subject and has asked if I could help him make a Hydro-Electric generator at home as an experiment. I am more than happy with building the turbine bit. I was first thinking of using the tap outside to provide us with the power source (water-flow). The thing I'm not sure of is how to turn the spinning turbine into electricity and use it to do something effective for him to see. It can be something as simple as lighting a small bulb or sounding a buzzer.

 

Then I got thinking about maybe plumbing something up to the drain pipe outside and somehow "storing" the electricity and using it later on to demonstrate the energy stored. For example: connecting a small bulb or a small radio with a switch and leaving it off for a while (a few rainy days) to generate a stored charge of electricity, then turning on the switch to show my nephew what Hydro Electricity can do.

 

Any ideas on this would be very gratefully received as I'd love to make something impressive with him whilst he is interested in the subject. Sadly though, building generators and storing the electricity is a subject that I have never gotten into which is why I am asking for help from the more experienced.

 

Thank you in advance,

Paul

[TonyMcC]

If you google - science fair wind generators - you may get some ideas. Basically they describe how you can use an electric motor as a generator. You can drive the motor from your turbine to make it generate electricity.

[swansont]

Simple generator

http://amasci.com/amateur/coilgen.html

 

I imagine there are other designs on the web. Storing the energy for any length of time is a different matter. I'd go with the instant gratification of lighting a flashlight bulb, but note that the link cautions you that not any old light bulb will work.

[pjl83]

Thanks for the replies.

 

I'll read more into the science fair wind generators. There's some good stuff there.

 

The simple generator looks good too. I am I correct in saying that I could use stronger magnets and thicker wire to producer a higher power output? Is there a way of calculating a set-up to give me 2 to 3 amps using the same type of generator only larger and maybe with a plastic casing and bearings for the shaft to give me more efficiency?

[TonyMcC]

Don't forget that you can't get more power from a generator than you put in (Power = joules of energy per second Watts). A small head of water coming out of a water butt through a small pipe won't provide enough water flow to drive anything but the smallest of generators. I think lighting something like a torch bulb would be a more realistic aim. If you are thinking of using the water mains pressure to drive your turbine the water company might not like that as presumably the water used would be wasted. In theory a larger container providing a greater head of water delivered through a bigger pipe could be effective in driving a bigger, or more powerful, generator (at least for a short time).

[pjl83]

Thanks for the comments. The wasted water comment is correct, I will think of some kind of container maybe using the rain water collector we have.

 

At this point I don't want to get too wrapped up in the equations. I just want to keep it simple and make something happen so that I can show my nephew a working experiment. I'll build a small generator and measure the voltage and current that it produces. From there I'll decide what to connect it to. I'll keep you guys up to date on the results.

 

Thanks

Paul

[the.archer]

Well you have a good idea, it only need perfection. If you are using tap water then, I think you should use a dynamo which can be easily obtained from bicycles-and they are normally rated 6V 24W meaning they give out about 4A. This energy is big enough to run a few electrical appliances such as phone chargers, electric lamps with low wattage and radios. And with some electronics you can use this hydro energy to run your laptop.

Wont you be wasting the water? May be no. You can place your dynamo-turbine in an enclosed case such that the water through it is used for other purposes- while watering your garden or washing your car you may thus be getting free electricity to charge your phone battery or laptop, or lanterns. If you plan this project well it will result into something useful as I have just explained. I wish you best of luck and in case of drawbacks or further clarification don't hesitate to post a question.

[pjl83]

Thanks again for the replies guys.

 

I've got the magnets and the wire now, I'll start building over the next couple of days and let you know how I get on.