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Giving turbines a second wind – how to stop early decommissioning

News | Energy Hub
April 1st 2020

Jonas Ballani, Core Technology Developer, Akselos

The energy sector is no stranger to headlines shouting about environmental damage. Usually these stories talk about problems caused by fossil fuels, yet last month saw a flurry of headlines about the surprisingly high environmental cost of wind turbines. Research found that over 8,000 turbines in the US, and 3,800 in Europe, are decommissioned and this is creating huge amounts of unsalvageable refuse – particularly the gigantic fibreglass blades.

Because turbine blades are larger than airplane wings and built to withstand hurricane-level winds, they’re virtually impossible to recycle or repurpose. As a result, the only way to dispose of them is to chop them up and bury them – a solution which is counterproductive from a sustainability perspective. One very important point that may not be considered, is that many of these turbines could still have decades of safe service in them. And, with the number of decommissioned turbines set to rise significantly in the next decade, we urgently need to find ways to manage and mitigate the problem through the use of innovative technology like digital twins.

Built to last

Although most turbines have a recommended operating life of 20 years, many are being dismantled and buried after only 10. Part of the reason is that operators are looking to upgrade to newer, more efficient models. However, in many cases, the overriding rationale is concern about the condition of the blades. Worn out blades could pose a safety hazard which leads engineers to make over conservative estimates and disassemble turbines earlier than necessary, artificially limiting our renewable capabilities. It’s also worth noting that in most cases the recommended operating life of 20 years will also more than likely be over conservative, based on worst case environmental scenarios considered at the design stage.

The issue is set to get worse in the coming years, both because more turbines than ever are hitting their recommended end-of-life dates, and the fact that new blades are twice the size they were a decade ago. In Europe, thanks to stricter waste management regulations, operators are already running into major problems disposing of old blades. And if the issue continues to hit headlines in Bloombergand The LA Times, US companies could soon find themselves having to shoulder new regulatory obligations as well.

In the long-term, the challenge will be addressed by developments in material science that allow either better recycling of existing blades, or the creation of new turbines, designed to be broken down and reused. However, such solutions could be years – potentially decades – away. In the meantime, operators need to take pre-emptive action by investing in technology that can help reduce the rate of decommissioning by extending the life of assets.

Predict it and fix it

When looking to extend the life of wind turbines, operators need visibility of the entire asset, with a detailed and accurate view of each individual component. This is because having a detailed structural analysis of every part provides a far more accurate estimate of fatigue life. Currently, the decisions about whether to decommission a turbine is usually made after a physical inspection. However, a better, more comprehensive way is to use a physics-based digital twin that uses data from sensors across the asset to build a near real-time digital replica. This provides far more detail than a one-off inspection, allowing operators access to the real time condition of the turbine 24/7, and enabling highly configurable simulations to address uncertainties in loading conditions and material properties. For example, if the wind conditions at the site are lower than initially anticipated, this can be incorporated into the model, allowing operators to more accurately understand the remaining life of the asset.

Such insight becomes even more valuable when considering the fact that the 20-year lifespan for wind turbines is only a recommendation, averaged across a host of different models and conditions.  Introducing a digital twin allows engineers to replace guesswork with an unprecedented level of understanding of the real structural life of any asset. Having a holistic view of real time asset condition means that engineers can quickly identify any elements that are in danger of wearing out and carry out pre-emptive repairs, simultaneously helping to avoid early decommissioning and reducing OpEx.

Accelerating the transition

Managing the energy transition is the biggest challenge facing humanity today. We urgently need to enable wide-spread renewable energy generation. A key part of that transition is ensuring that renewables – especially wind – is as efficient and as a result, as cheap as possible, which means eliminating unnecessary decommissioning and preventing additional waste.  

Engineers are doing their best, but without tools that provide full visibility of structural integrity, many turbines will end up being pulled down and buried in the ground before their time. It’s up to operators to invest in digital twin technology which can help then strike the precise balance between efficiency and caution and decommission assets at their true end of life. Which in our experience so far, has been up to 25 years later than planned.

This article originally appeared in ReCharge

 

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