navitron
 
Renewable Energy and Sustainability Forum
Welcome, Guest. Please login or register.

Login with username, password and session length
News: Anyone wishing to register as a new member on the forum is strongly recommended to use a "proper" email address - following recent spam/hack attempts on the forum, all security is set to "high", and "disposable" email addresses like Gmail, Yahoo and Hotmail tend to be viewed with suspicion, and the application rejected if there is any doubt whatsoever
 
Recent Articles: Navitron Partners With Solax to Help Create A More Sustainable Future | Navitron Calls for Increased Carbon Footprint Reduction In Light of Earth Overshoot Day | A plea from The David School - Issue 18
   Home   Help Search Login Register  
Pages: [1]   Go Down
  Print  
Author Topic: electric motor as a generator  (Read 2636 times)
billi
Global Moderator
Hero Member
*****
Offline Offline

Posts: 8907



WWW
« on: January 26, 2009, 09:00:24 AM »

which electric motor can i use to generate electricity

I would like to play a bid  and built my own micro hydro turgo generator ( i guess around 1500 RPM)

All parts are easy to find , but have a problem to find a good affordable DC generator ..... to charge a 24 volt battery

Sure could search for a lorry alternator (but they have brushes ?) and i think quite open

Windturbine ones are not fast spinning

So can i not just use an electic motor (magnet) and use it as a generator ?  I hope to generate  between 100-300 watt

Thanks Billi

Logged

1.6 kw and 2.4 kw   PV array  , Outback MX 60 and FM80 charge controller  ,24 volt 1600 AH Battery ,6 Kw Victron inverter charger, 1.1 kw high head hydro turbine as a back up generator , 5 kw woodburner, 36 solar tubes with 360 l water tank, 1.6 kw  windturbine
Richard Owen
Hero Member
*****
Offline Offline

Posts: 2253


Navitron PV Installer


« Reply #1 on: January 26, 2009, 10:10:07 AM »

Don't know much about DC.

Do your inverters/chargers have the capacity to take an AC input?

If so, the easiest way to diy is to use an induction motor as a generator. There's even a book on the subject



If your gear can't take an AC input, I don't think it's hard to rectify a generators AC to DC.

I'm sure others will describe a simpler solution.
Logged

44 Yingli 230Wp panels feeding into 2x Solar Edge SE5000 inverters.
20x 58mm SE, 20x 58mm SW, Solar Thermal feeding 320l thermal store.
10kW heat pump.
300W of Hydro Power.
stephend
Hero Member
*****
Offline Offline

Posts: 562



WWW
« Reply #2 on: January 26, 2009, 10:21:48 AM »

Futurenergy sell the generator component of their wind turbines as a separate part - outputs 24v or 48v DC.  (I've no idea whether the torque and RPM's of a hydro system would match that of a wind turbine...)

Logged

billi
Global Moderator
Hero Member
*****
Offline Offline

Posts: 8907



WWW
« Reply #3 on: January 26, 2009, 06:45:25 PM »

Quote
Do your inverters/chargers have the capacity to take an AC input?

Thats possible , but cause i only think of  100-300 watt it would cause to too much switching in the inverter , cause the let me say 150 watt of the turbine are supplied to the house and then power assisted  by the battery   and i have a 1.1 kwh waterturbine that will go on the AC side of my system ( feeded by a lake that i will drain only occasionally to charge the battery /instead of a diesel backup) or to run a heatpump of it

So try to get a trickle DC charging idea running when lake is overflowing .....

Anyhow thanks for the input

Stephend i have seen the futerenegy ones , but think i would need gearing then ....


billi



Logged

1.6 kw and 2.4 kw   PV array  , Outback MX 60 and FM80 charge controller  ,24 volt 1600 AH Battery ,6 Kw Victron inverter charger, 1.1 kw high head hydro turbine as a back up generator , 5 kw woodburner, 36 solar tubes with 360 l water tank, 1.6 kw  windturbine
guydewdney
Hero Member
*****
Offline Offline

Posts: 4320



« Reply #4 on: January 26, 2009, 06:49:15 PM »

Whats wrong with brushes? Most alternators on trucks, which run for thousands of hours - and the replacements are cheap and easily available.

(unlike the replacements on my new motor - a 50hp(37kw) 300v 1000 rpm - which retail at 800 quid!  Shocked )
Logged

Pic of wheel on day 1
7.2kW Waterwheel and 9.8kW PV
billi
Global Moderator
Hero Member
*****
Offline Offline

Posts: 8907



WWW
« Reply #5 on: January 26, 2009, 10:43:35 PM »

i think my move will be towards a DC generator (PM)  like the one in my Motorwind turbine   .... they say its  rated 1.5 A regardless  of volts upto 95 volts  and use a solar MPPT tracker to charge the 24 volt battery

so the same generator at 70 volt produces about 100 watt   and only around  40 watt at 24 volt  bike

Just thinking

Logged

1.6 kw and 2.4 kw   PV array  , Outback MX 60 and FM80 charge controller  ,24 volt 1600 AH Battery ,6 Kw Victron inverter charger, 1.1 kw high head hydro turbine as a back up generator , 5 kw woodburner, 36 solar tubes with 360 l water tank, 1.6 kw  windturbine
stephend
Hero Member
*****
Offline Offline

Posts: 562



WWW
« Reply #6 on: January 27, 2009, 09:59:57 AM »

The guys at volvoxengineering have recently announced a 48V DC diesel/veg oil generator.  Since they build these themselves they might be able to source just the alternator for you.

Logged

sunshinekid
Full Member
***
Offline Offline

Posts: 162



« Reply #7 on: January 27, 2009, 08:49:11 PM »

You could just make a generator.   I've never done it myself, but read about using a wooden circular disc with around 10 holes drilled around the edge and neodymium (rare earth) magnets glued in the holes.

On another wooden disc, you glue hand-wound coils.  Then using the shaft and bearings from some other motor, you have a completely brushless generator.

Sound like fun?

Steve
Logged

If you know what you're doing, you're not learning anything.
Pages: [1]   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.20 | SMF © 2013, Simple Machines
SMFAds for Free Forums
Simple Audio Video Embedder
Valid XHTML 1.0! Valid CSS!