About Windmill Power

Watch Out For Wind Turbine Power Ratings:

The power ratings usually given by the manufacturers for wind turbines
are nearly useless, in that they are determined at wind speeds much higher that
you will normally see.  A good rough formula to keep in mind in evaluating
different wind turbines is:

Annual Output (KWH/year) = 0.01328 (D^2) (V^3)    


Where D^2 is the blade diameter in feet squared,
and V^3 is the wind velocity cubed in mph  — this is the year round
average wind speed — see wind maps below.Wind turbine energy production

So, a 10 ft diameter wind turbine in 12 mph average
winds might produce about (0.01328)(10^2)(12^3) = 2300 KWH/year

 Note that the energy produced is proportional to the
cube of wind speed — having enough average wind speed is everything in wind turbines. 
Use the wind maps discussed below and a wind survey of your site to determine
if a
wind turbine will actually payoff.

The graph is of the wind energy equation shown above
for various wind speeds and turbine blade diameters. 

See also:
Solar and WIND water pumping


ARE wind turbine in Oregon         
photo by J. Hall

Wind Power
Step One — Avoid the scams There are some very heavily advertised guides for sale on the Internet in
the $50 range that promise that you can make a small wind turbine that will
provide "80%" of your homes power for a couple hundred dollars. 

You can be sure that anyone making these kinds of claims is a scammer —
don’t waste your money.  You will find plenty of free information below
for reputable sources.

Wind Power for Dummies,

Ian Woofenden, 2009


you are interested in a wind turbine installation for your house, this is
probably the best $20 you can spend.

Ian is a very long time wind expert
— he does wind workshops from his wind powered home in the San Juan’s, and
has been the wind expert/editor/author for Home Power for many years. 

The book covers the whole process of investigating whether wind is workable
for you, how to find the right wind turbine and tower, and all the rest. 
The best getting started reference you will find.

Small Wind Electric System — U.S.
Consumer’s Guide,

Wind & Hydropower Technologies Program,


www.eere.energy.gov ,,,

A US consumer wind guide, as well as guides for many state.  Other
wind publications as well

good guide for residential size wind turbines.  Covers restrictions on
locations, wind required for good performance, sizing turbine to meet your
needs, cost and economic return.

The state guides include wind maps for
the state in question.

Wind-Electric Systems simplified,

Ian Woofenden


How to
get articles from Home Power …

Power Magazine issue 110, Dec/Jan 2006.  A  introduction to the various types wind powered
electric generating systems and the components that make them up.
Wind Turbine Buyer’s Guide,

Mick Sagrillo,  Ian Woofenden

How to
get articles from Home Power …


Home Power magazine article, issue 131, June/July 2009. 
A very good article from two recognized wind power experts that 
provides some good and realistic advice for people thinking about a wind
turbine .    Covers all the basics, and provides a rundown on
wind turbine models available in the US/Canada. 

If you are serious about wanting to install a wind turbine that will
generate the amount of energy you expect, and will not be a nightmare to
maintain, this article is a must.

The other critical item that is not covered in detail is making sure your
site has sufficient wind to make a wind turbine work — this is covered in
articles below.

Wind Power — Renewable Energy for
Home, Farm, and Business

Paul Gipe’s web site:



Wind Power, 2004 edition, Paul Gipe

An excellent, all around, in depth book on wind power.

Paul Gipe’s website
has a lot of good articles and reference material.

Got Wind?  —
How to use  the Wind Resource Atlas of the United States

US set of wind maps:


and, another:


(has some more detailed maps for NW)

Similar for Canada:


Got Wind? -- Using the wind resource atlas The
Wind Resource Atlas of the United States will give you a rough idea if you
are in a locations with wind potential — here is
how to use it.
NREL Wind Turbine Payback Spreadsheet

www.eere.energy.gov …

(Thanks to Derek for relocating the lost link to this useful


Spread sheet estimates economic return wind turbine installationThis
spread sheet from NREL allows you estimate the economic return from a wind
turbine on your site.  You enter information on your wind turbine, your
site, and financing — it provides a graph of cash flows over time. 
You will need a good estimate of the average wind on your site, and the cost
to install  to get useful numbers from this spreadsheet.
Site Analysis for Wind Generators


How to
get articles from Home Power …

Site analyis for wind generatorsHomePower
Magazine article, issues 40 and 41

The most important factor in
determining if you can successfully use wind power is how much wind you
have.  This is not an easy thing to determine — this article
tells you how.

Scoraig Wind — Hugh Piggott’s Homepage


Scoraig wind -- DIY wind turbine informationHugh Piggott’s
excellent web site on building wind generators. 
Plans and design  information on building a wind generators from scratch. 
Plans, books, workshops, ….

The "Windpower Workshop" book gets very good
reviews from people who want to build their own (as do his actual

Anatomy of A Wind Turbine,

Ian Woofenden, Hugh Piggott,


How to
get articles from Home Power …

Power Magazine article, issue 116

A good basics article explaining the internals of a wind turbine.  
Good to understand whether you want to build one or buy one.
The American Wind Energy Association


good reference website for wind power.  Some valuable materials for
people interested in small wind systems.

Lots of good material.
Apples and Oranges 2002 — Choosing
a Home-Sized Wind Generator

Mike Sagrillo

How to
get articles from Home Power …

Home Power magazine article, issue 90

good advice on choosing a home size wind generator from the guru.  Lots
of comparison specifications for numerous commercial wind generator

Tower Economics 101, 102 and 103

Mick Sagrillo

How to
get articles from Home Power …

Wind turbine towers analysisHomePower
Magazine article, issues 37 — 39

Very good article on the economic
benefits of using a tall tower, and how to decide how tall.

Harvest the Wind

Michael Hackleman and Claire Anderson

Mother Earth News


Earth News Article, Issue 192

Good introduction to determining if a wind
system will work for you, and the important elements of a wind system.

Kid Wind




site intended for students wanting to learn about wind power, but lots of
good materials anyone interested in wind power — including lots of hands on
building projects.
Ontario Landowner’s Guide to Wind Energy" (free download)

Paul Gipe and
Jame Murphy




guide for land owners considering installing one or more large wind turbines
on their land. 

Logging Wind Velocity

These gadgets log wind speeds over an extended period to see if you have
enough wind to make a wind generator pay off.
Jarvis (and other) Wind Data Logger

Backwoods Solar (and select "Windmills"):


APRS World, LLC:


wind data logger will record wind over an extended period for import to a PC
spread sheet.  You can then calculate what a particular windmill model
will deliver.  About $180.
Inspeed Wind Speed/Direction Loggers




options for measuring and logging wind speed and direction.  Some are

Some of the solutions require a PC to be on at all times to log
data, so you would want to have a very low power use PC.


Piclog – PicAxe
based Wind Logger



is a wind logger based on the PicAxe microprocessor chip that you can build
yourself.  It interfaces to a PC to store and view the data.

Another PicAxe based logger with built in data storage …

Windmeter/Anemometer by Infidigm



windmeter to measure and record wind speeds.   The experts
recommend measuring wind speed at your site for a year before investing in a
wind turbine.  Here is one way to do it.

Another option is to install
of the small wind turbines (like a Air X) and use it to see how much power a
larger wind turbine would generate. 

DIY Windmill Plans and Information
Scoraig Wind — Hugh Piggott’s Homepage


Hugh Piggott’s
excellent web site on building wind generators. 
Plans and design  information on building a wind generators from scratch. 
Plans, books, workshops, ….

The "Windpower Workshop" book gets very good
reviews from people who want to build their own (as do his actual






a source of nitty-gritty detailed information on building wind generators. 
Many projects described.
Homebrew Wind Power,

Dan Bartmann and Dan Fink, 2009, 320 pages




Dan’s website — consulting, training, seminars…

And, Dan F blogs here…

very good new book from the two Dans that run the OtherPower.com website
(just above). The book gives very detailed instructions on how to build a 10
ft wind turbine.  The design of the turbine is one that the Dans have
perfected over the years.   Complete instructions are included for
building the alternator, furling tail assembly, and carving the blades. 
All of these part designs benefit for years of refinement and many
workshops.  Most of the parts for the turbine can be locally purchased,
while some of the more difficult to find parts can be purchased from
OtherPower.  The book also covers scaling their design to other sizes,
tower construction, and wind generator theory.  More than of 300 pages
of kind of information you only get through long experience and many builds. 
I would not try building a wind generator without reading this book and the
Piggott books first.
Building a 10 ft Piggott/Otherpower
style wind turbine



good set of pictures on building the Piggott/Otherpower style wind turbine.


Quite a bit of detail in the photos.

This is an Otherpower Diaries entry.

Tom’s 5.5 KW, 20 ft
diameter wind turbine and 140 ft tilt-up tower

Full construction details…


Sullivan’s 20 ft diameter, 5.5KW  wind turbine and a 140ft tall
gin-pole tower. 

The turbine is Tom’s version of a Prairie Technologies 5.5KW, grid tie, AC

The 140 ft tower was completely designed and built by Tom.

Quite a project!



Full details …

DIY Windmills from The Back Shed


Detailed plans for a DIY windmill with a minimum of special parts and tools



is a terrific site for build it yourself windmill information, and getting
better all the time.   It includes very detailed picture
plans for a moderate size windmill based on the Fisher Paykel motor. 
The plans use standard steel sections, and a require a minimum in the way of
special tools.

Oct 09: this site gets better and better — a great
collection of material on home built wind machines.

"Now for the Wind






very good personal website on designing and installing a PV and wind system
that is grid tied with battery backup.

Lots of detail and helpful information on design, choosing components,
installing, wiring, towers, suppliers, permitting, …

How I home-built an electricity producing Wind



shows the details on how he built his 4 ft wind turbine using a 
surplus DC motor for the generator.  Full details are
provided on the construction, as well as a number of useful design
information links.  Total cost was $140.
Wind Stuff Now




personal site on DIY wind generator design and build.  Several projects
described, program for wind generator sizing. 

An interesting site with new "stuff" added frequently.

Kits for small DIY windturbines.

The Lenz2 turbine in picture at right is an ongoing project that was
featured in Popular Science.  —>

Building a Wind Generator From Scratch,

Chuck Morrison




very nice set of picture plans and text guidance for building a 7 ft
diameter wind generator.

Very detailed.

Wind Blue Power


Here is a series of videos for a wind gen built from the WindBlue
alternator rotor:

Part 1

Part 2 …

Part 3 …

sells full windmill kits as well as a selection of parts to make windmills
— including alternators, blades, tails, charge controllers, …

One nice thing about this site is that they are honest about the

output of their windmill kit …
Maine-Built Windmills From Scratch

Everett Russell

How to
get articles from Home Power …

Home Power Magazine article, issue 79

article on building wind generator system from scratch from someone who has
been doing it since 1937.

Dragon Fly Wind Generator Plans/Kit



plans for a 9ft diameter wind generator.  Kits for some of the part
also offered. 
Colorado Wind Power



good "how to" on making what appear to be strong, lightweight composite wind
turbine blades.

Other material on this site of interest to DIYers,
including making wood blades, stators, …



Wind Odyssey

Dick Anderson


How to
get articles from Home Power …

Home Power Magazine article, issue 82

nice article on rebuilding an Enertech 1800 wind generator.  Lots of
detail on what’s involved in a project like this.

Prototype 10 KW Wind Turbine

Plans for 10 KW Wind Turbine

(Thanks to Tom for re-finding this link)

appears to be a very professionally designed, large, home built wind
Blade Carving 101





a detailed how-to on laying out and carving wood wind turbine  

And, details on the 14 ft diameter wind turbine that the author

Old Jacobs — Current Again

Peter Kuebeck

How to
get articles from Home Power …

Home Power Magazine article, issue 89

article on restoring used Jacobs wind generators.

Total Homebrew — starting small to
learn the basics

Michael Lew

How to
get articles from Home Power …

Home Power Magazine, issue #82

Good article on an all DIY very small scale wind generator system.

Old Jacobs — Current Again

Peter Kuebeck

How to
get articles from Home Power …


Home Power Magazine article, issue 89

article on restoring used Jacobs wind generators.

Prairie Turbines Breezy 5.5




Turbines sells plans for a 5.5 KW wind turbine.


The turbine is said to produce about 3 KW at 12 mph wind speed. 
And, that it can be built for about $4000.

The Wood 103 — A wooden 100 Watt
Wind Generator

How to
get articles from Home Power …

Power Magazine article, issue 88

Being a woodworker, I really liked this
article.  It looks like a good way for one with woodworking skills to
experiment with wind power generation.

Wind Generator from Fisher Paykel
Washing Machine



instructions on turning the motor from a Fisher Pakel washing machine into a
wind turbine alternator from the Your Green Dream website.

Because of its unique construction, this motor makes a good alternator.

Wind Power
Betting the Farm — Wind
electricity Pays Off


How to
get articles from Home Power …

Home Power magazine article, issue 96

Description of grid intertied medium size wind generation system. 
Details economics, planning and installation.

Wind Power History

Visit to Veldkamps Meul’n in Bellingwolde


http://greenbits.com/ …


Fascinating pictures of an 1885  wind mill and all the internal mill

20 meter diameter, 4 blade traditional Dutch design.

Still in operation.

New Designs
The Energy Ball


www.homeenergyamericas.com … North America


interesting new wind turbine design.

Said to be quiet and efficient. 
Appears to be well made.  About $5600.


(Thanks to Jeff for suggesting this)

A Sampling of Wind Generator Suppliers

(listed alphabetically — I have no direct experience
with any of these suppliers — so, beware!)
ARE Wind Turbines



of 12ft and 24 ft diameter wind turbines.
Bergey Wind Turbines





well known supplier of small wind turbines.
Eoltec Wind Turbines



of an 18 ft rotor diameter wind turbine.
Jacobs Wind Turbines




revival of the famous Jacobs wind turbines that were so popular and durable
in the 20’s.
Kestrel Wind Turbines



of wind turbines with rotors ranging from 5 ft to 12ft diameter.
Mariah Power Windspire 1 KWH
Vertical Axis Wind Turbine




Article from The Energy Blog…


A soon
to be available vertical axis wind turbine.

It is 30 ft high by 2 ft wide
with guy wires.  It is anchored in a concrete foundation.

Said to produce 1900 KWH per year with an average 12 mph wind.  Said
to be very quiet.

Price $4000.

Proven Energy Wind Turbines



of a line of wind turbines ranging from 8 to 30 ft rotor diameter.
quietrevolution Wind Turbines




A new
vertical axis design that is targeted for urban locations.
Southwest Windpower



well know supplier of small wind turbines ranging up to 15 ft rotor
Skystream 3.7 Wind Turbine from
Southwest Windpower



is kind of the opposite of Do-It-Yourself, but I thought it was interesting.

The Skystream is a 12 ft diameter turbine that is designed for grid
connected residential use.  It comes as a package that includes all the
electronics and grid tie inverter.   Kind of a plug-and-play wind
turbine.  It claims to be designed to fit into residential areas — low
noise, street lamp type tower, …   About $15,000 plus
installation.  It is said to produce 400 KWH per month in winds
averaging 12.3 mph. 

Some problems have been reported with low power output, so make sure this
has been sorted out, and that you understand roughly how much power will be
produced in your particular installation.