Siting of small VAWT turbines in the UK


Factors affecting the success of a wind turbine are :reliability, windspeed, swept area, cost and efficiency. I found a Quiet Revoluiton QR5 turbine at the botanic gardens in Edinburgh and I am checking out these criteria.

There is a good rule of thumb that says a wind turbine should be 30 feet above any obstruction within 300 feet. Windspeed is highly critical for energy production since the energy depends on the cube of the windspeed. There is hardly any wind for turbines sited below the ‘canopy layer’ of the tree tops. For more details check the Carbon Trust wind siting tool. The company state that “Please note that the minimum recommended average wind speed for a QR5 is 5m/s.” But they were willing to sell one to go on this site, maybe just for “demonstration purposes”?

Reliability is very important since the kilowatt hours of energy generated will depend on the hours the turbine is available. The QR5 is out of action so far as I am aware due to problems with the blade attachments. Vertical axis turbines do have intrinsic fatigue problems which along with the problems of starting and stopping, and the problems of putting them on proper towers have made them a poor choice for wind energy.

The turbine is a nice size (5m high x 3.1m in diameter) but in relation to its cost it will not produce much energy even on a good 5 m/s site. The turbine alone costs £25,000. It does not matter how efficient it is it can never produce more than about 12,000 kWh per year at a 5m/s site, and the manufacturers claim 7,500 kWh per year. A HAWT of similar size and a fraction of the cost would do the same.
Nice ornament? Or a big waste of money, and another big embarrassment to the small wind industry?

This entry was posted in Rooftop madness, UK small wind scene. Bookmark the permalink.

6 Responses to Siting of small VAWT turbines in the UK

  1. Leslie says:

    I studied this type of design in the mid 1980,s based on references and research from New Scientist mag from the late 1970,s etc. A couple of universities built really big ones, but all agreed that the design was poor, due to metal fatigue and the high revs required to produce usefull power. It seems to me that another manufacturer has not done his research properly!!

  2. Nikki says:

    A good introduction about diy wind turbine. You should give a detailed introduction on control and brake system. These are two important parts of a samll wind turbines.wind generator

  3. Anonymous says:

    A but this is 2100 not the 70s or 80s.
    VAWTs have come a long way sense then, like 50 rpm and blade design.
    I always worshiped the HAWT but now I dont know.
    What do you think?

  4. marco says:

    Dunno…I pass by the Gardens everyday, and I see it gingerly spinning away, even with low wind…maybe the fact that the wind comes mainly from the west and there are not trees on its way counts for something…definately nice to look at, got to say!
    cheers.

    • admin says:

      Thanks Marco, it’s great to know that it does spin, because I have not seen that. However this turbine is designed to produce several kW and it is (in my opinion) wasted on a site with such low winds. I am in the USA just now and there is a cultural tradition of using the wind here and they (mostly) understand the necessity of putting wind turbines on tall towers where the wind is good and steady. If you look at the energy production in kWh, you will see that it’s very simple economic common sense. See also the recent report by the Energy Savings Trust entitled ‘Location, location, location’.

Leave a Reply

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