UK certification scheme list gets shorter

Posted on 24/09/2011 by hugh

The list of small wind tubines that hold the coveted MCS certification is growing shorter as time goes by.  In order the qualify for the lucrative Feed in Tariffs, you need to own a turbine on this list.  Recently the Eoltec has disappeared and now following technical problems the Proven 35 has also gone.

The MCS administrators have made this statement:

MCS today announces that the certification of the both the P35 and the P35-2 has been suspended, pending further information on the recent failures it has experienced.

We are now advising all customers of either the P35 or P35-2 to follow the safety advice of braking those systems, and then contacting their installation company for further advice.

The Proven 11 (formerly the 6 kW Proven) is now on the approved list    

Evance…      Evance Wind Turbines Limited      R9000…      
    Evoco…     Evoco Energy Limited     Evoco 10…     
    Gaia-Wind     Gaia-Wind Ltd         GW 133-11kw…     
    Proven Energy P11…     Proven Energy         P11…     
    quietrevolution QR 5 v1.3…     quietrevolution     QR 5 v 1.3…     
    quietrevolution QR 5 v1.4…     quietrevolution     QR 5 v 1.4…     
    Skystream 3.7…     Southwest Windpower, Inc.     Skystream 3.7…     
    Skystream Marine 3.7…     Southwest Windpower, Inc.     Skystream Marine 3.7… Info
    Xzeres -442SR Xzeres Wind Corp     Xzeres-442SR Wind Generator…    

There are several other good products out there.  For example the C&F turbines from Galway are worth watching.  See this rather positive write up.There are other old, established manufacturers who are weathering the storm gracefully whilst others boom and bust.  Here is a quote from one:

Over the years we have seen a number of small wind companies take venture capital or go public as “penny stocks”. With their newfound millions they hire high-power managers and marketers with no background in small wind, they build slick web sites, they advertise and promote extensively, and they woo dealers with visions of untold riches. They focus much more on quantity of sales versus quality of sales and they don’t address product and support issues with the same priority. The result is often hyped-up expectations, dissatisfied customers, a sinking reputation, and an inability to build sales based on word of mouth referrals. Sales slow while overhead expenses continue, losses build, more money is poured into the company, and at some point the money-men pull the plug. They thought they were in for a quick buck, but they had no idea how difficult the small wind business really is.

Posted in UK small wind scene | 27 Comments

Dyocore in San Diego

Posted on 23/09/2011 by hugh

By claiming for a 1.6 kW wind turbine on your roof, you could get it paid for by California State subsidies.  This one can produce that much (in the sales pitch) although it’s only the size of a 200 watt turbine.  The trouble is that it can’t deliver energy because it doesn’t have access to any significant amount of energy if it is so small and in such low winds.  Basic rules to learn about using wind energy.

Paul Gipe explains the details here

Ian Woofenden gives the quick verdict here.

Windpower is not viable in low wind areas like this.  Turbines are too expensive to waste on rooftops.  To catch useful wind they have to be on a tower well above surrounding obstacles.

Here is a complaint made by the Californian Energy Commission in July:

The complaint alleges that DyoCore, Inc., (“DyoCore”) violated the intent of the Energy
Commission’s Emerging Renewables Program (“ERP”), and, in particular, Appendix 3,
Section (A)(2) of the ERP Guidebook by submitting grossly overstated information
regarding the performance characteristics of the DyoCore SolAir wind turbine (model
no. S80015dc) (“DyoCore turbine”) in order to have the wind turbine ‘listed by the
Energy Commission as eligible for use under the ERP. The complaint requests that the
DyoCore wind turbine be immediately removed from the Energy Commission’s “List of
Eligible Small Wind Turbines” on the ERP website, that the Energy Commission provide
guidance regarding the resolution of pending ERP applications for rebate reservations
and payment requests for small wind systems using the DyoCore turbine, that the
Energy Commission take all action necessary to recover ERP funds that were paid as
rebates for small wind systems using the DyoCore turbine, and, if appropriate, that this
matter be referred to the Attorney General for investigation and prosecution.

Posted in products/technical, Rooftop madness, wind systems tutorial | Leave a comment

Interesting German site for building turbines

Posted on 23/09/2011 by hugh

Markus in Switzerland told me about this interesting site.  Parts of it are in German (which I never learned to read, but can using Google translate).

http://www.nadaparasiempre.com/hobbies/wind-energy/

Daniel has made an interesting spreadsheet for designing axial alternators.  You can download it here. http://www.nadaparasiempre.com/hobbies/wind-energy/generator/index.html It allows you to design for a particular cut-in rpm accurately.  But take care, because it does not calculate the rpm and the tip speed ratio when the wind gets a bit stronger.  It is likely that your rpm will be too low and the turbine will stall, so the performance will not be s predicted in the spreadsheet.

German discussion forum here http://www.kleinwindanlagen.de/Forum/cf3/

Posted in construction | Leave a comment

Calculating the energy production of a wind turbine

Posted on 21/09/2011 by hugh

The bottom line with a wind turbine is how much energy it produces.  Do not confuse this with the maximum power output!  Rated power output is only achieved at rated windspeed, which will only occur from time to time.  The energy produced depends on the average power and not the peak power.  This in turn depends mostly on the turbine’s physical size (diameter) and the site average windspeed.  Most of the energy will be produced while the turbine it generating less than its rated maximum power.  In these everyday winds, the power depends on the size of the turbine, and not it’s power rating.

Here is a chart I did that estimates annual energy production for different sized turbines in different annual mean windspeeds.  It is a bit pessimistic (turbines do exceed these predictions in many cases) but it shows the basic trends.

Manufacturers will offer similar looking estimates of the energy production of their turbines in kWh per year assuming various different site average windspeeds.  These figures can also be calculated, using the data for the wind turbine’s power output versus windspeed (the Power curve) and the data for how many hours per year the wind will blow at different windspeeds (the Windspeed Distribution – usually a “Weibull” Distribution rather than real data).

There are spreadsheets for doing this calculation available from various sources.  http://bergey.com/ for example under “technical stuff” offer what they call WindCAD Performance Models for their turbines, based on their power curves and various site parameters including tower height etc.

It can be fun to play aroud with this and see how various changes in input conditions affect the output energy.  I like to add graphs/charts to help my understanding.  Like this version: windcad hugh  Be aware that this process is entirely subject to the quality of the input data.  You can add your own power curves it you wish.

Site windspeed is defined in terms of the mean windspeed, and also a ‘Weibull k factor’ that describes the shape of the curve (pointed or broad).  It’s very hard to predict the mean windspeed.  Don’t rely on a simplistic post-code based prediction for this!  It’s fair to assume that the k factor will be around (or just under) 2 for most good UK and US sites.

Better power curve data is one of the consequences of independent testing being done to achieve MCS in the UK and NREL testing in the USA.  NREL actually publish the data on their web page.

Another site with a similar spreadsheet is http://www.windmonitor.de/ If you click on ‘English’ and look under ‘Service’ you will find a ‘yield estimation tool’.

The Carbon trust windspeed estimation tool for the UK allows you to enter power curve data, and thus estimate the energy production for your site.  Unfortunately the tool is not particularly accurate but it can help you to understand the consequences of siting a turbine under a tree.

But if you prefer larger turbines you can use this link

http://wiki.windpower.org/index.php/The_power_calculator

Posted in UK small wind scene, wind systems tutorial | 6 Comments

Komic Monastery electrification at 14,800 feet

Posted on 21/09/2011 by hugh

Thanks to Vivek Mundkur for these photos from the heart of the Himalayas.

Posted in developing world, People | 4 Comments

1200mm wind turbine workshop at Eirbyte

Posted on 19/09/2011 by hugh

Don’t miss the Irish pipe music and some clever construction ideas.

Eirbyte is here.

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

Proven Wind Turbines go bust.

Posted on 17/09/2011 by hugh

Proven Energy have gone bust.  Here is a good source of information:

http://www.businessgreen.com/bg/news/2109634/proven-energy-cash-crisis

also http://www.express.co.uk/posts/view/271863

and http://www.navitron.org.uk/forum/index.php/topic,14973.0.html

I was a big supporter of the Proven wind turbine in the 1990s.  It’s built like a tank in contrast to so many flimsy products in the small wind world. But my enthusiasm for the company waned gradually as I witnessed their exaggerated claims and heard from their many unhappy customers (during lengthy development of new products).  In recent years they got a big cash injection and became even more arrogant.  I can’t feel much sympathy for the company management, but I am sorry for the workers, the dealers, and even more so for the customers, who have already suffered far too much.

Posted in UK small wind scene | 30 Comments

Price of Neodymium finally levels off

Posted on 16/09/2011 by hugh

There’s an interesting article here about the situation with global supply of neodymium magnets.  Price of Neodymium (Nd) has increased roughly tenfold in two years, but shows signs of leveling in recent weeks.

Thanks to Markus Hugentobler for sending me this link!

Posted in construction, developing world, ferrite magnets | 3 Comments

The first ever wind turbine build completely by people with a disability

Posted on 16/09/2011 by hugh

I Love Windpower – Tanzania are working with Yombo secondary school for people with a disability  to build one turbine of the type ‘Piggott – 3 meter’ plus assemblies and parts, which will be used for the next ordered turbine. “It is our intention to make this workshop a kind of preferred supplier for sub-assemblies of wind turbines.”

The article is here

Posted in construction, courses, developing world | Leave a comment

CometME on WindEmpowerment facebook page

Posted on 13/09/2011 by hugh

See the WindEmpowerment Facebook page for photo albums and a video from CometME about the construction of the 4200 (14 foot diameter) turbines there with 20 magnets.

Posted in CometME, construction, Video links | 1 Comment