Turbine Selection

Many prospective wind developers ask me how I decided the turbine make and model to buy.

My viewpoint was very much shaped by Soren Krohn, who at the time, was the Executive Director of the Danish Wind Turbine Manucturers Association.  As part of my research on wind, I made a trip to Denmark, to talk to wind turbine manufacturers and owners, to learn all I could about wind energy technology.  Denmark is the Silicon Valley of the wind industry.
At the time, there were several technology options.  Some manufacturers, such as Enercon, made a big deal of their direct drive models.  These turbines have no gearbox, which reduces the number of moving components.  At the same time, their generator is much larger than gearbox models, and so if it failed, it would be a very costly repair.  There was NEG Micon’s stall regulated models, compared to Vestas’ active pitch models.  Passive stall turbines automatically stall because of blade aerodynamics, when winds exceed about 14 m/sec, slowing down the rotor, ensuring the generator output does not exceed the rated capacity of the turbine, causing overheating.  Active pitch turbines have motors that adjust the blade pitch, and let wind pass when winds are strong, accomplishing the same thing.  It was confusing to know what to buy.
So I asked Soren for his advice.  “Which technology is best?  The manufacturers all make claims about how their technology is simpler, or superior.  Direct drive manufacturers claim that eliminating the gearbox reduces maintenance cost.  Passive stall manufacturers claim that the simplicity of passive stall, with no need to pitch the blades, reduce points of failure.  The active pitch manufacturers claim that their techology eases some of the strain on the tower and blades.  Which one would you choose?
He thought about the question for a minute.  “All of the technologies work.  What matters is who has the best service in your local area.”

That answer made sense to me.

At the time that I ordered the V80, in early 2002, there were 3 commercial scale wind turbines operating in the province.  Ontario Power Generation had a Tacke 600 KW model built in 1995, and a Vestas V80 built near the Pickering plant.  Phil Andres had built the Vestas V47 at Port Albert.  Vestas was the only company with a service facility.  (Tacke had been bought by Enron, which later sold their wind division to GE).

It makes no sense for a small developer to do their own service.  Servicing wind turbines is a very specialized field, and I believe factory training and updates are essential to doing a good job.  There are many parts of the turbine that are proprietary, especially the software, which has pitch algorithms, and protection and control, to ensure safety and to  ensure that no damage is done to the turbine if something is wrong.  The Ferndale V80 has temperature sensors in 17 places, and if any of those overheat, the turbine shuts down to protect itself.  It measures voltage, and shuts down if voltage drops too much, or if the current is imbalanced.  Both of these conditions could damage the generator.  It has an optical rotor speed sensor, to shut the turbine down if it spins too fast.  It has a flash detector in the transformer, which will detect arcing or fire.  It is measuring wind direction, and the yaw motors adjust the nacelle to face the wind in the optimal direction.  It is measuring wind speed, to adjust the blade pitch to let some of the wind pass by if it is too strong, and shut down in very high winds, to protect the structure.  The software manages automatic restarts if conditions improve.  It logs events.  It place calls to technicians when problems are detected, in order to ensure speedy response.

So there is a lot to the controller and software.  And it is proprietary.  The turbine has had several software updates, to provide for increased protection from field problems found elsewhere, and to optomize output.

And of course, parts availability is crucial.  Summoning parts from Europe or California can result in significant downtime. Stocking an inventory of spare parts requires a critical mass of installed turbines before it makes financial sense.  Somebody has to pay for that.  And a critical mass of installed turbines is also essential to allowing service technicians getting good at diagnosing and doing repairs.  There is nothing like solving a problem once to make solving it the next time far faster and easier.

I look forward to the day there are third party service organizations for wind turbines.  But meanwhile, factory trained technicians and local service parts are essential.

When the V80 was ordered, Huron Wind in Kincardine had just placed an order for 5 of them.  I always tell people I let them share my boat, although it may have been the other way around.  Transportation costs for small projects can be greatly reduced if they can be delivered in conjunction with other projects.

So, the reason I ordered Vestas was because they were the only ones with service.  They were the world’s largest turbine manucturer, a wind turbine owner in Denmark was happy with their service, and they had enough turbines installed locally to have a local spare parts inventory and experienced technicians.  And I could buy a 5 year warranty, with availability guarantees.
The V80 was a relatively new model in 2002.  It certainly had its teething problems.  But Vestas always looked after it.  Have I always been serenely happy with them and with the turbine?  No.  But at the end of the day, they stood behind their product very well.  To me, that is the measure of a good supplier.
Today Ontario has turbines installed by GE and Vestas.  The turbine at the Ex is a Lagerway.  The Melancthon project in Shelburne, the Port Burwell project, and the upcoming Prince project near Sault Ste. Marie use GE turbines.  The project near Goderich has Vestas V80’s.  More projects are in development, and no doubt other models and manufacturers will begin to build in Ontario, so developers will have more choice in suppliers with a critical mass of installations.
The biggest challenge for small developers is to get the interest of the overly busy manufacturers in your project.  They probably deal with 20 interested parties, who will consume all of their time, for every one who has the where-with-all to build a project.  So be patient and persistent.  They need to be convinced that you are the one in 20 who can actually get a project built.  And once they are convinced they will deal with you.  But service should be at the top of your list of concerns and questions.

All of the technologies work.

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