REUK.CO.UK
The Renewable Energy Website
This is the printer friendly version of the Permanent Magnet Generator article from the Renewable Energy Website REUK.co.uk.
Click here to print
this article.Printed at 09:54am 21st November 2009
Permanent Magnet Generator
Build a wind or water power system with around a PM Generator
While it is possible to build your own alternator from powerful Neodynium Magnets (1) and coils of enamelled wire (2) an amateur should consider purchasing a ready made and tried and tested Permanent Magnet Generator for their Wind Turbine. Wind turbine blades (for example, home made DIY PVC (3) or carved wooden (4) blades), a waterwheel (5) (connected through a gear box), or even a bicycle can then be attached to spin the generator and produce AC electricity (6).
The generated electricity must then be passed through a suitable Bridge Rectifier (7) (35A rectifiers (8) available for sale here from £1.79 each) to produce DC electricity which can be stored in batteries (9) and/or passed through a power inverter (10) for domestic use.
Pictured above is such a Permanent Magnet Generator (used by Dick Strawbridge in BBC2's It's Not Easy Being Green (11) on his Waterwheel (12)) available in 12, 24, 36, and 48 Volt configurations. Gearing wastes energy and generates nuisance noise, so PM-Generators for wind (and waterwheel etc) applications are designed to produce high power outputs at low RPM.
This Futurenergy (13) model weighs in at just 7kg and the main body is just 18 x 7cm. The 12V model generates 662 Watts at 380 RPM, and 53 Watts at just 260 RPM. The 48 Volt model generates just 42 Watts at 380 RPM, but 1472 Watts at 610 RPM.
Higher voltage generators are more suited to locations with high average wind speeds and strong gusts, and the lower voltage generators more suited to locations with lower wind speeds on average and limited gusts.
Buy a Permanent Magnet Generator
The cheapest place to purchase a permanent magnet generator suitable for use in renewable applications is usually eBay (14). Click here to search eBay now for Permanent Magnet Generator (15), or here for Permanent Magnet Alternator (16). (Far fewer results are usually returned when searching for alternator rather than generator although these devices are all technically alternators since they output AC electricity.Web Link References
(1) http://www.reuk.co.uk/Buying-Neodymium-Magnets.htm(2) http://www.reuk.co.uk/Enamelled-Magnet-Wire.htm
(3) http://www.reuk.co.uk/PVC-Wind-Turbine-Blades.htm
(4) http://www.reuk.co.uk/Make-Your-Own-Wooden-Wind-Turbine-Blades.htm
(5) http://www.reuk.co.uk/Introduction-to-Water-Wheels.htm
(6) http://www.reuk.co.uk/Three-Phase-Basics.htm
(7) http://www.reuk.co.uk/Bridge-Rectifier.htm
(8) http://www.reuk.co.uk/Buy-35A-Bridge-Rectifiers.htm
(9) http://www.reuk.co.uk/storage.htm
(10) http://www.reuk.co.uk/Power-Inverters.htm
(11) http://www.reuk.co.uk/Its-Not-Easy-Being-Green.htm
(12) http://www.reuk.co.uk/Introduction-to-Water-Wheels.htm
(13) http://www.futurenergy.co.uk
(14) http://rover.ebay.com/rover/1/710-53481-19255-0/1?type=1&campid=5336029669&toolid=10001&customid=
(15) http://rover.ebay.com/rover/1/710-53481-19255-0/1?type=3&campid=5336029669&toolid=10001&customid=&ext=permanent+magnet+generator&satitle=permanent+magnet+generator
(16) http://rover.ebay.com/rover/1/710-53481-19255-0/1?type=3&campid=5336029669&toolid=10001&customid=&ext=permanent+magnet+alternator&satitle=permanent+magnet+alternator
Article from REUK.co.uk:
http://www.reuk.co.uk/Permanent-Magnet-Generator.htm
Published: 21st July 2008
© REUK 2009