4200 alternator options

Posted on 19/08/2011 by hugh

I haven’t built a lot of turbines 4200 mm diameter (14 footers for the North American market). I use 16 magnets the same as the 3600 (12 foot) turbines but put them on a larger disk (450 mm/18 inches) compared with 400mm/16 inches. This allows me to put in a lot more copper to compensate for the lower rpm of the larger 4200 rotor blades.

However Jay Hudnall of Tripalium and Tieole in France has told me that he uses 20 magnets on the larger rotors and gets a higher power output.    With the rising price of neodymium magnets this might not be very attractive to people in low wind areas, but it does offer better efficiency and higher peak output in stronger winds.

For those who wish to charge 48 volt batteries, the 20 magnets recipe is to use 54 turns of 2 mm diameter wire in 15 coils.  For grid tie, using a Windy Boy 2500 inverter use 260 turns of 0.9mm diameter wire.   The 20 magnets allow you to comfortably reach a peak output of 2500 watts instead of the 1700 watts that I would normally recommend.  This inverter also operates at a higher voltage (up to 600 volts) whereas the 1700 only goes up to 400V DC.

Higher voltage and higher peak power will not win you much extra in the low winds when power is scarce, or the medium winds where most of the energy comes, from but it does improve the efficiency and productivity in higher winds for those blessed with really good sites.

Comet ME in the middle east are using these 20 magnet rotors in their latest project at Tubah.

Posted in CometME, construction, developing world, France, People | 13 Comments

Frans Beudt’s control systems

Posted on 13/08/2011 by hugh

Frans Beudt  lives in the northwest Netherlands.  Average wind 5,5 m/sec

Youtube channel here

“Testing the windmill at 5 Bft .  Results till now OK ,   Rpm stays around 300 , Amps 20 ,Volt 30 .  Electronic system doing good .”

“The actuator is made of a battery-screwdriver with a threaded rod m6 and a travelling nut , distance adjustable with micro-switches.  The blade-angle can be controlled by Rpm ,Manual, and anemometer with a micro-controller.  A generator can be connected with a timing-belt or co-axial with your design (which I made before succesfully).  It’s not for beginners ,but I like mechanical-engineering.”

Below is an older concept for control by servo on the tail.

” The tail is moving by a small actuator ( as used for adjustment hospital beds).
The generator is made according to your design and it has an electrical break , double safe .  The rotor of 10ft has a lot of extra power . And I see sometimes burned stators on Internet (Alan)  I decided so.”

additional information addes 24th August:

“My findings : In high wind there is a direct effect to a lower constant  rpm 300 .
I can hear a low noise level of stall in high wind.
Nice load current 20 – 25 amps.

The electronical circuit board can be more compact .It takes 400 millies max.
An LCD readout is preferred.
Waiting for more wind .
Regards : Frans.”

Posted in construction, People, Video links | Leave a comment

V3 now sell complete wind turbine kits!

Posted on 12/08/2011 by hugh

These bespoke kits comprise of a set of three hand-carved blades, a complete alternator, mounting and an electrical system. We have been building these turbines for over 5 years and as a result you can expect the highest degree of craftsmanship. The kit does require some assembly and assumes a certain level of knowledge about renewable energy and wind power. The kits are designed to charge a battery bank and can come as a 12v, 24v or 48v system.

V3 website here

Posted in construction, People, products/technical, UK small wind scene | Leave a comment

Single phase, chain driven alternator project with ferrite magnets

Posted on 28/07/2011 by hugh

Chris Olsen has been busy experimenting and reporting his findings on the Fieldlines board

This single phase stator for a ten magnet dual-rotor turbine is his answer to the rising cost of neodymium magnets.  As always Chris is pushing against the accepted way of doing things (3-phase, direct drive etc) so his project gives rise to some interesting discussions.

As an update to this post I offer this link to a discussion on the ‘Backshed’ forum where Chris describes his latest (2-bladed) creation and I argue the case for single stator alternators.

Posted in construction, ferrite magnets, People | 4 Comments

WindAid Volunteer programmes in Peru

Posted on 13/07/2011 by hugh

WindAid is a non-profit social responsibility organisation based in Trujillo, Peru and we run environmental development projects building wind turbines for communities in Peru without access to electricity.

The dates for our upcoming programmes are:

·  FULL!!! 18th July – 19th August 2011

·  26th September – 28th October 2011- 2 spaces left

·  7th November – 9th December 2011- 6 spaces left

·  30th January – 2nd March 2012

·  26th March – 27th April 2012

Posted in construction, developing world, Notices | 2 Comments

Pedro’s microwave ferrite magnet turbine

Posted on 12/07/2011 by hugh

Pedro Bernardo has been sending me photos of his latest project using ferrite magnets from a microwave oven.  Pedro lives in a village close to a small city called Marinha Grande, Portugal.  (Since I first posted this message he has put all of these details on the Fieldlines discussion board.)

Stator with 9 coils (2 x 1.6mm wires)  46 turns, connection star/series, 13mm thick.

The generator had  two 6mm disks, 12 magnets each (microwave magnets in pairs at first), diameter 306mm.

The idea is to reach 12 volts close to 200 rpm, and use the recipe book 2400 mm rotor.  Bench testing showed a 12V cut-in rpm closer to 226 rpm.  Pedro then stacked on a third magnet level on each rotor and got the cut-in rpm down to 215 rpm.

According to my calculations this alternator should be comfortable at a power output around 400 watts with 40% efficiency.  This is compared with the neodymium version producing 700 watts with 70% efficiency.

However the magnets are much cheaper, and very durable.  Also the alternator speed characteristic is much more suitable for the blades.  The higher internal resistance of this stator helps to push the speed up as the windspeed increases, thus preventing stall.

I trust that Pedro will secure the magnets against flying away!

Posted in construction, ferrite magnets, People | 48 Comments

Eoltec 6kW turbine is MCS approved

Posted on 06/07/2011 by hugh

A (shortened) press release from Orkney wind energy company Bryan J Rendall Electrical:

The Eoltec Scirocco, co-developed by Kirkwall company Bryan J Rendall Electrical (BJRE), is the first wind generator of its kind to meet Class 1 standards under the Microgeneration Certification Scheme.  This means it is rated to withstand the extreme wind speeds experienced in exposed areas such as the north and west of Scotland.  The Scirocco is now the only Class 1 turbine eligible for Feed in Tariff (FiTs) payments.

The 6 kilowatt (kW) Scirocco has been certified as generating more than 10 per cent more electricity than its nearest rival.

Mr Rendall said the certification process had been extremely challenging, and at times very frustrating.

“We have achieved a Class 1 rating on what is effectively a shoe string budget,” he said. “Other manufacturers have had multi millions of pounds in financial help and investment to carry out this testing.

“We have done it virtually all in house, with only 14,000 (pounds) of much appreciated funding from Highlands and Islands Enterprise.

The BJRE Eoltec Scirocco 6kW wind turbine has been certified as having a Reference Annual Energy Production  (RAE) of 9881 kWh per annum in a mean annual windspeed of 5 metres/second.  This performance  is over 10% higher than its nearest rival, and over 12.5% higher than the next nearest, according to RAE ratings published on their websites.

(Note from Hugh – the Evance turbine is rated to produce 8780 kWh/year in a 5 m/s average.  The Eoltec Scirocco makes 12.5% higher than this figure.  Eoltec do not reveal what their energy production would be at other mean windspeeds.  The  “nearest rival” is most likely the Proven 11 which does not as yet have MCS certification.

The vertical axis QR5 now also has MCS certification, but the rated output is only around 2000 kWh/year at 5 m/s wind.  This VAWT performs best in decent winds, but I only ever see it sited among buildings and trees where windspeed can’t be more than 3-4m/s annual average.)

Posted in UK small wind scene | 27 Comments

Wind turbines in Tajikistan

Posted on 22/06/2011 by hugh

Tajikistan

Jarty Gumbez #4 from an album of photos by Tony Nelson, Director etc4ca

Posted in developing world, People, products/technical | Leave a comment

Source for wind turbine parts/kits in France

Posted on 20/06/2011 by hugh

ventetsolaire“We provide parts, completed sections  or the complete 2.4 metre wind turbine kit for the enthusiast to create your own micro electricity generating station by using the wind as the natural resource.  This can then charge batteries or be used with a grid tie inverter (see product list).”

This site offers parts for my older 2005 design wind turbine in France.  Also an interesting little inverter for grid connection.

Wind turbine building parts are available in the UK from

www.Wind-Turbine-Supplies.co.uk

and in the USA from

www.forcefieldmagnets.com

and in Australia www.thebackshed.com although they do things differently down there 🙂

 

 

Posted in construction, France, People, products/technical | Leave a comment

Otherpower workshop at Buckville CO

Posted on 18/06/2011 by hugh

For those of you who do not read the Otherpower discussion board at Fieldlines, well, you should.

Here is a recent posting about a workshop at Buckville CO.   Dan Bartmann, George and Scottie guided a small group to build an ambitiously large turbine.

DanB has recently posted about a couple of other workshops they did at the Midwest Renewable Energy Association in Wisconsin here and here

These are not only good stories, but also contain a lot of technical details for the latest 12 foot machines being built.  “This is a 48V turbine, we wound the stator with two strands of AWG 15 wire in hand and 64 turns per coil.”, “We hit 48 Volt cutin at 125 rpm as usual.”  and “In an effort to fit as much copper as possible into this stator, we wound the coils (24 volts) with 33 turns each, using 4 strands of AWG 15 wire.  ”

The the 15 inch diameter rotors look lovely with their 2″ diameter, 1/2″ thick N42 neo magnets on (which cost $20 each now!)

My recipe book calls for 45 and 90 turns of wire(14 gauge), which has a higher resistance.  I use smaller 2″ x 1″ magnets, on a larger (16″) rotor disk.  I have a philosophy of using larger stators and less neodymium.

The Otherpower design can hit a higher peak power, but my alternator will be less prone to stalling the blades.

The Fieldlines discussion board is a good place to get advice, see what works for others, and be amazed.  Otherpower are the best guys at running workshops for homebrew windpower and related topics.  Check their web page Otherpower.com for dates and venues.

Posted in construction, courses, People | 3 Comments