THYmøllen – A Wind Turbine Made In Thy

In 2008, when the Danish government passed a law to further the production of energy through sustainable sources, the telephone lines became busy at wind turbine salesman Leif Pinholt’s office.

Thy WindPower ApS Oddesundvej 183
7755 Bedsted
Phone: 71 99 06 00
www.thymoellen.dk
Email: lp@thyml.dk

Grønkjærs Smede- og Maskinværksted Industrivej 12
7760 Hurup Thy
Phone: 97 95 11 76
www.gronkjaer-mv.dk
Email: info@gronkjaer-mv.dk

  • Guided tours: By appointment
  • Open: All year round
  • Language: Danish, English, German.

 

Leif’s company Dansk Vindmølleformidling (Danish Wind Turbine Facilitation) has been working in the field of dismantling, repairing and reselling some of the many small wind turbines that are replaced with larger turbines in Denmark. This work has provided Leif with an extensive knowledge of wind turbines and a worldwide network of customers and contacts. As the small scale wind turbines came in demand in Denmark, it was time to rethink the business concept. Second hand wind turbines can not be reused in Denmark due to the fact, that the dismantling of small scale turbines is subsidised by the government, in order to further the installation of larger wind turbines.

web_ThymoellenBBJ_1879_2010_09_16_17 Leif contacted business partners and Thy WindPower co owners Flemming and Bent Grønkjær who own Grønkjær Engineering Machine Shop in Hurup and have many years of experience in manufacturing wind turbines. The first type approval for a 7,5 kW wind turbine was achieved in 1983. In Flarup near Hurup one of the 7,5 kW wind turbines has been running from 1983 to 2012 when it was replaced with a new 6 kW THYmølle. Flemming installed a 11 kW wind turbine in Ettrup in 1986 which has been running without major repairs ever since.
This was a good starting point for setting up a production of small wind turbines and as it turned out, Flemming still had the blueprint for the 11 kW turbine in his drawer. Thus the company Thy WindPower ApS and a new THYmølle, TWP 6 kW was born – a residential wind turbine tailor made to suit the specifications in the legislation.

What is a Residential Wind Turbine?

6197345990_1cc78958ca_b In Danish legislation a residential wind turbine is defined as a small wind turbine placed in conjunction with a solitary property, whose sole purpose is to produce energy to that property, either in the form of electricity or hot water. It is further defined as:

  • having a maximum height of 25 m from foundation to the top blade tip
  • having a rotor diameter of up to 13 m
  • having a maximum effect of 25 kW.

Technical Specifications

In April 2011 the THYmølle type TWP 6 kW with a 21 m lattice tower was approved for installation. It is a three bladed upwind propeller turbine with wooden or glass fiber blades with a tip brake device. It has an active yaw system with a yaw drive controlled by a PLC computer in order to ensure that the nacelle and the rotor are always facing up wind achieving the highest possible effect.

  • Rotor diameter: 7,13 m
  • Nominal effect: 6 kW
  • Nominal speed: 98 revolutions per minute
  • Gear box and asynchronous generator
  • Mechanical brake.

To date, 200 6 kW THYmølle turbines have been installed in Denmark, and the TWP 6kW is now joined by a new 10 kW turbine as a result of a recent change in the legislation, making it more profitable for customers to install a 10 kW turbine. The new TWP 40 10 kW turbine is expected to produce up to 25 % more power than the 6 kW turbine. The design of the new turbine is very similar to that of the TWP 6 kW, yet the 10 kW turbine is fitted with broader blades, a 35 kW gearbox and a lattice tower with 5 mm thicker poles. The use of heavier components reflects the importance of a correlation between yield and quality of the components used. A durable design is more sustainable and makes for happy customers. The developing of the 10 kW wind turbine demonstrates how a relatively small manufacturer like Thy WindPower manages market competition so well. It’s good to be small because it improves the ability to adapt to a market, that is constantly challenged by an ever changing legislation.

Blade Design

For small wind turbines, like THYmøllen, with a limited rotor area of 40 m2, the best possible blade design is paramount to how well the wind turbine performs. It is really only the outermost third of the blade, that revolves fast enough to pull the rotor and thereby generate power. The part of the blade that is located closest to the blade hub does not pull enough to generate power. That is why, a broad blade profile with a large contact area extending all the way to the tip of the blade is important. The blade is fitted with a brake device at the tip of the blade, functioning as an emergency brake, automatically slowing down the rotor if wind speeds exceed a certain level. A unique feature of the THYmølle blades are the so called “winglets” that increases productivity as well as significantly reducing the noise emitted from the blades.
The first 40 THYmøllen turbines came with wooden blades made by the staircase manufacturer BV-trappen in nearby Koldby, but because of customer demands, blades are now glassfiber produced by Olsen Blades in Odder.

Local Manufactures

thymoellen-03_16_2011_28 Thy WindPower places great importance on the fact that as many of the components as possible are produced locally. Furthermore the durability of the product is important, and Thy WindPower very seldom experiences complaints. All components are standard items that are easily available. The metal parts are laser cut and bent at KK Metal in Hørdum, Limbo Boats I/S in Agger produces the glassfiber nacelle/turbine housing, Grønkjær Engineering Machine Shop in Hurup welds the frames and installs the wind turbines, while the controls are put together by electrician Jørgen Poulsen at the workshop in Hurup. The tower is produced by Alfred Priess in Vinderup near Holstebro. Even the insurance company is the local Thisted Forsikring. The local rooting contributes to the creation of jobs in an area that is somewhat occupationally challenged and is an integral part of the branding of THYmøllen.

THYmøllen – The Silent Wind Turbine

web_ThymoellenBBJ_1888_2010_09_16_25 In 2012 statutory noise testing was performed providing THYmøllen with a sound certificate. Test results proved that the THYmøllen turbine fully complies with the allowed noise levels of the noise ordinance thus merits the title as the most silent small wind turbine on the market. It is the components of the turbine that reduce the noise emission. For example, the specially designed blade tips, a parallel axis gearbox and the low revolution rate of the rotor. Also the lattice tower has been carefully selected because of its low level noise abilities, that are partly due to the fact that the legs are solid metal. Many other wind turbine manufactures deliver lattice towers with hollow legs that react almost like organ pipes when exposed to the wind – not a desired quality in a wind turbine.

Company Visits

Thy WindPower welcomes visitors from local schools and other institutions. Each year many trainees from Nordic Folkecenter for Renewable Energy in Ydby and students from Aalborg University are given a tour of the facility. Through a Danish/American exchange program a group of students from Florida visit Thy WindPower each year after having been to see Siemens Wind Power first.

Historical Overview

thymoellen-03_16_2011_13 1983: The first type approval of Flemming Grønkjær’s 7,5 kW wind turbine.
2010: Leif Pinholt and Flemming and Bent Grønkjær form the company Thy WindPower ApS and a new 6 kW THYmølle wind turbine is born.
March 2011: The lattice tower is approved to a load capacity of 1600 Newton. Required maximum load capacity is 1350 Newton.
April 2011: The TWP40-6 kW THYmølle wind turbine with 21 m lattice tower is type approved for installation and operation according to the Danish Energy Agency executive order no 651 of the 28th of June, 2008, concerning the technical approval of construction, production, installation, maintenance and service by the certified company and according to the Approval of wind turbines with a rotor diameter of 40 m2 or less with a maximum capacity of 25 kW.
November 2013: The TWP40-6 kW THYmøllen wind turbine no 200 is installed
November 2013: The new TWP40-10 kW THYmølle is approved for sale in Denmark.

Production Data

thymøllen i kulden

The THYmøllen type TWP40-6kW with 21 m lattice tower:

  • Three bladed upwind propeller turbine
  • Wooden or glassfiber blades with tip brake device
  • Active yaw system with a yaw drive controlled by a PLC computer
  • Rotor diameter: 7,13 m
  • Nominal effect: 6 kW
  • Nominal speed: 98 revolutions per minute
  • Gear box Renold (UK) and asynchronous generator
  • Mechanical brake.

The THYmøllen type TWP40-10kW with 21 m lattice tower:

  • Three bladed upwind propeller turbine
  • Wooden or glassfiber blades with tip brake device
  • Active yaw system with a yaw drive controlled by a PLC computer
  • Rotor diameter: 7,13 m
  • Nominal effect: 10 kW
  • Nominal speed: 105 revolutions per minute
  • Gear box Renold (UK) and asynchronous generator
  • Mechanical brake.