Repairing Wind Turbine Parts: Driving the Circular Economy

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New Parts vs Repairing Old

Often being a manufacturer is at odds with being a repair company. If you repair more, your customers need less new product, your revenue falls and you can’t meet your cost base. Similarly, if you build a higher quality product with greater reliability, you will have a higher cost, be less competitive and see less volume in after sales.

Usually this situation produces a dichotomy of companies. Those who produce and those who repair. It would be like Mick Jagger busting out the dust pan and brush after one of his gigs. It’s not his problem, he’s made his money and he gets no satisfaction (pun intended) from cleaning up after himself. But what if manufacturers were rewarded for thinking about the entire product lifecycle rather than short-term profits?

Current WTG component procurement strategies

There are over 4000 components that make up a wind turbine and whilst the OEM’s assemble all of these parts together they do not make them; they buy them from specialists. They put together a specification to include space envelope, operating environment, testing requirements and send it to some very keen suitors to bid. The lowest compliant price gets the most production volume.

Is the component parts strategy working?

This procurement strategy, whilst commercially sound, has a few issues. The WTG OEMs can’t be specialists in everything so they rely on the technical capabilities of their component partners to either conform to or modify the specification. Often at this stage, with no field data, or understanding of neighbouring components, they are asked to commit to a certain product lifetime (>20 years) and various warranties (60 months for onshore, 72 months for offshore) which are onerous.

These European WTG OEMs are currently facing some difficult questions about turbine quality from wind farm developers and operators at a time when Chinese OEMs are dominating the top ten.

Buy cheap, buy twice

The true cost of a bad wind turbine is enormous, you fail to recoup the R&D investment, your order book gets shredded, staff jump ship and the reputation of quality that you have cultivated since the 90s becomes tarnished. All of this at a time in wind when we have achieved grid parity, beat conventional power and new wind and PV projects dominate energy generation developments. We are now only in a pissing content with ourselves.

Component manufacturers want to make quality product. No design engineer endures all that maths and education to make the cheapest product with the lowest quality. Some will see this as an optimisation problem to solve but most want to make the best, innovate and drive performance. Over engineering is punished through lower OEM volumes and ultimately less market share. The irony being is that their customers want quality wind turbines in the first instance and if the turbine doesn’t manifest quality, the risk lies with the OEM in availability and warranty claims. You reap what you sow.

Lifetime Cost Thinking

WTGs are now being design for more than 30 years. This is a long time for components that see difficult operating environments coupled with the dynamic nature of wind power production. Cycles are inconsistent, diurnal temperature swings producing condensate and add in the inconsistency of the people that maintain them. All we can predict is that 30 years of operation is going to be unpredictable for a new turbine at a new site.

If we sold a component on a lifetime cost, just as OPEX costs are modeled for 30 years and added to CAPEX for levelised cost of energy (LCoE), then we can afford to over-engineer. Through looking at a component through a 30-year lens we can change how we see cost based procurement. We could make a unit that lasts 30 years and can be repaired rather than 5 cheap units that fail and go in the skip in service of the same wind turbine. How would you go about designing a car if you knew you had to look after it for 30 years? You make it easy to work on, with good quality parts and more documentation than the Library of Alexandria.

Taking ownership of a wind turbine

You don’t get that in wind. You have to steal documentation, dongles and laptops with the intensity of the British Museum on a supermarket sweep. You have to play detective to figure out which part number, goes in which turbine and who makes it? Wouldn’t it be wonderful if there was a Haynes manual and supplier list with each turbine? If the part that failed was repairable, you would go back to the manufacturer first and get them to repair it. That way they have to eat their own dog food and can carry that responsibility from cradle to grave. If they are responsible for repairing it too, they are more likely to make it easier to work on in the first place.

But what can I do?

It’s very easy to get depressed when faced with the scale of problems that blight the wind industry today. We keep reinventing the wheel and despite our sustainability credentials we are passengers to the relentless marching of capitalism. All the money moves upward, stuff gets bigger, waste gets made and China wins through cheating.

If you have a problem-solving mind, working in large organisation it can be frustrating to drive change. I’ve found it easier to drive change through working with small organisations, particularly in repairs, that have an environmental conscience with an engineering mindset. With the relentless drive for new WTG design R&D teams are transferred from platform to platform as new are developed. This leaves a handful of support engineers to clean up the following twenty years of reliability issues. As they age, platforms get classed as legacy, despite being life extended and being sited in the best wind class locations. Like a boomer waiting out retirement in a public sector job.

For those that still have old turbines (<2MW) and have no hope of retiring. I urge you to share your pain with me, I might know someone…





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