Wind Turbine Considerations for an Irish climate

Even though I am only in the early stages of gathering wind data for my house I decided to do some research into wind turbines and the practical considerations one must keep in mind.
Mike Sagrillo in the 2002 August September issue of Homepower 2002 wrote an article titled “Apples and oranges – choosing a home-sized wind generator”. Mike made some good suggestions about selecting a wind turbine. They are:
1 – The KW rating is not enough of an indicator for its performance, you need to find out at what wind speed the turbine generates that amount of energy.
2 – Look at the power curves, if your average wind speed is 5 m/s then that is what you should make your decision on, not on peak values which rarely occur. Different manufacturers will rate their peak power at different wind speeds so try and pick a speed that reflects your site and ascertain the power output for that wind speed.
3 – Lower rpm turbines are usually quieter turbines. In order to run at lower rpms they use a large rotor diameter which gives them a larger wind swept area i.e. can use more of the wind. Several of the lower rpm turbines can operate at lower wind speeds and generate decent power.
4 – Heavier turbines are more rugged and will usually last longer. In Ireland we have significant gusts etc so a rugged turbine is more preferable.
5 – 3 bladed turbines wind generators avoid yaw chatter, which happens when a two-bladed machine yaws. The term “Yaw” refers to a wind generator pivoting on its bearings around the tower top to follow the continually changing wind. Some two bladed turbines do use a spring plate mechanism so as to absorb some of the yawing vibration so as to mitigate the yawing chatter
5 – Warranties etc, a turbine may need to be lowered and greased once a year, how much will that cost etc
6 – Proper blade and rotor balancing is critical so as to have smooth operation. Mike notes that a unbalanced rotor will display tail wagging symptoms.
Urban-wind.org have a catalogue which list the European Urban Wind Turbine Manufacturers.
Using the above criteria I reviewed the turbines with a view to quiet operation and power ratings around 5 – 6 m/s.
The following turbines met my initial criteria
Iskra 5 kW turbine, 200 rpm, 1.284 kW at 6 m/s. Rotor diameter 5.4 meters, 3 blades (page 23), Power and rpm rated at 11 m/s
Travere Industries 2.1 kW, 440 rpm, 1.120 kW at 5 m/s. Rotor diameter 6 meters, 2 blades (page 45), Power and rpm rated at 8 m/s
Tulipower HAWT, 2.5 kW, 0.958 kW at 6 m/s, Rotor diameter, 5 meters, 3 blades (page 47), Power and rpm rated at 10 m/s
Wind Energy Solutions, 2.5 kW, 0.958 kW at 6 m/s, Rotor diameter, 5 meters, 3 blades (page 53), Power and rpm rated at 8.5 m/s

5 comments

  1. Hi doctor, I’ve been reviewing your blog entries and find them very interesting, I too was interested in gathering information about wind turbines and noted that the proven wind turbine comapny in scotland provide a 3 day course on installation, maintenance and general over view of wind energy. It costs 1000 Stg excluding vat. From my own perspective I was thinking of the 6 kW proven wind turbine whenever grants and smart metering come into play. I would agree with you in saying that monitoring the wind for a year would make my choice better. I have a heat pump installed using the seabed as the ground collector and living on the coast I would assume that wind energy would be ideal on the exposed coast of Donegal that I live in. I currently use around 20K unit of ESB per year. Any helpful hints from you.

  2. Paraic Conneely says:

    Hi there the proven wind turbine is by far the best the 6 kw will
    give you 6 kw @ 12m/s but the most important thing to consider
    is the cut out speed the proven turbines have no cut out speed
    and will produce electricity in storm force winds due to their flexi blade design other turbines will shut themselfs down in
    strong winds to protect themselfs hence when you would most expect
    to be producing power in strong winds your turbine would have shut down and all that wind energy lost

  3. Frank Gethings says:

    I would disagree with Paraic that the most important thing to consider is the cut-out speed. There are a number of factors to consider but I would not be overly concerned about the cut-out speed or indeed a very low cut-in speed. Because of the infrequency of these wind speeds there is very little energy to be gained from them compared to the overall annual energy capture.
    The Evance Iskra 5kW turbine manufactured in the UK is a well designed and good performing machine which is also very reliable. Its annual energy output is comparable to the larger Proven 6kW and since it is an upwind machine it does not suffer from tower shadow as the downwind machines, such as the Proven, do. Like the Proven the Evance R9000 does not cut out in high wind speeds, it continues to generate up to 60m/s (134mph). It is a low rpm machine and it regulates its speed by pitching the blades as the larger wind farm turbines do. It is a direct drive permanent magnet a.c. generator machine and looks really well, very sleek and aerodynamic.

  4. Ger Slattery says:

    I have installed a number of the Evance R9000 to date and they are as Frank has indicated a very sleek,aerodynamic turbine.
    The most important part of installing any turbine is the correct site not the cut out speed or the rated KW..
    If you put up a Proven or Evance on a poor site then it will only lead to dissatisfaction,low yield and generally give micro-wind turbines a bad name.
    On a good site 5-10m/s both turbines will produce many useful units of power but at lower speeds the Evance will produce more.It is only at the high wind speeds that the proven kw will produce more power and these high wind speeds are less frequent than the 5to10m/s average speeds.

  5. liam noonan says:

    Hi Ger,
    Thanks for the comment.
    The selection of site is critical and as you point out if you put up a turbine in a poor site then you are causing long term damage for the reputation of the installer, turbine and industry.
    I find the SEI wind maps are a useful starting point along with the method 1 analysis from RETscreen.
    Liam

Leave a Reply

Your email address will not be published. Required fields are marked *