Offshore wind is set to provide up to a third of the UK’s energy by 2030, as the government commits to raising capacity to 30GW in the next decade. Achieving this target is a key milestone on the path to net zero in 2050, requiring a significant rise in annual installations.
As momentum gathers behind a green recovery, investors will be keen to ensure that they back projects that are environmentally and financially sound. Wind energy has already proved to be a resilient haven for investors globally due to a continued fall in cost and a recognition of its increasing long-term prominence in the global energy mix.
Life extension of existing wind farms will be a key tool to support the UK as it builds out wind capacity. Crucially, the financial case for life extension is a key driver, enabling wind farm owner operators to boost profitability and reduce energy costs even as they continue to improve the green credentials of the technology.
Recent events have accelerated the uptake of digitalisation, as owners and operators look to minimise site work and make the most of remote monitoring. Looking past 2030, half of UK wind farms will be over 20 years old. If the correct predictive maintenance strategies are ingrained into the entire UK wind market, the savings could be £140 million over the next five years.
The environmental and financial benefits of life extension using digitalisation
Life extension using digitalisation can boost the value of wind farms by 12 per cent, which will unlock the investment needed to help the UK hit its zero carbon targets. And crucially, running wind turbines for longer allows owners and operators to extract more clean energy from them, making a larger contribution to the UK’s green targets over their lifecycles. Keeping older wind turbines working profitably for longer also means more wind farms potentially operating at the same time, increasing wind’s contribution to the energy mix.
But the incentive for owner operators to extend asset life is already in place. A turbine pays for itself in the first 10 to 15 years of its life. Selling electricity produced after this, once operations and maintenance costs are considered, represents pure profit. Figures from a leading renewable financial institution show that the largest factor by far affecting the value of a project was the ability to extend life – the difference between running assets for 25 years versus 20 years is huge.
The capability to produce additional energy from a wind farm offers one avenue of revenue. There are also significant benefits gained from reducing waste through digitalisation during the whole lifecycle of a wind fleet. Less construction, less frequent replacements of carbon-hungry steel components, less demand for rare earth metals – these things are now possible due to advances in digital tools.
Finally, a better understanding of the technology, and better materials, means life extension can support the move to a circular economy. A challenge for the wind industry has been that most components get thrown away. If a gearbox fails, all the bearings are replaced regardless of their wear as operators don’t want to risk failure. Now, there is increasing interest in refurbishment – figures from SKF show that using a refurbished bearing saves 90 per cent of the energy compared to producing a new bearing.
The choices facing owner operators as their assets age
Wind turbines are robust machines. With the right maintenance strategy, they can provide clean energy for around 20 years. But inevitably, as turbines age, they lose efficiency. Older turbines tend to be smaller too, placing aging wind farms at a competitive disadvantage.
European markets that were early adopters of wind technology, such as Germany, have already started to see an increase in aging assets. As the UK wind industry matures and significant proportions of wind turbines start to approach their decommissioning phases, wind farm owners and operators have three options.
They can let the wind turbines run to failure, withholding further investment and allowing the assets to come to a natural end. This can create problems, such as the need to consider the decommissioning process early and putting a potentially profitable site out of action.
Alternatively, they can repower the turbines, completely replacing older turbines with larger ones, or carry out extensive works to replace the gearbox, blades, and generator – commonly performed in the North American market. This can often be economical compared to building a new wind farm as infrastructure such as the tower, foundation and grid connection can be reused. It is also a good choice for owner-operators of very windy, profitable sites with small, low powered turbines installed. However, the process can be lengthy due to re-permitting delays and may still incur significant expenditure during installation, not to mention downtime.
Owners and operators have a third, more sustainable opportunity. Advanced sensing technology is now affordable, transforming the economics of retrofitting condition monitoring on older, sub-megawatt class turbines. Where it was previously not worthwhile to invest further in some older turbines, technological advancement and reduced production costs have made this not only a viable solution, but one which makes sound financial sense.
Further incentive for maximising power production during the life extension phase is that modern energy tariffs are significantly lower than older agreements underpinned by various subsidy mechanisms. Digitalisation is vital for reducing downtime, but implementation costs are even more vital. Reliable and affordable solutions with proven ROI can make the economic case for faster, cheaper and more reliable life extension even more attractive.
Bringing old assets online
The key to unlocking the potential of aging assets is digitalisation. The advent of low-cost sensors covering key indicators of machinery health such as vibration has given owners and operators a deeper understanding of the health of their fleets. Using artificial intelligence and machine learning combined with the real-world expertise of data analytics and engineering partners, has enabled predictive maintenance to revitalise assets, extending useful asset life by up to 25 per cent.
Through detailed analysis and affordability modelling, owners and operators can modernise their aging fleets in a targeted way, reducing expenditure. Ultimately, a greater overview of asset health allows for flexibility and control, allowing owner operators to reduce uncertainty and make better decisions on which assets are worthwhile to invest in, and how.
Data analysis combined with engineering expertise helps owner operators to assess the options which can be taken before uprating a generator or replacing a gearbox using objective facts. Changing the filtration system or the lubricant, increasing oil flow to crucial areas of the machinery, changing blade bolts, installing autogreasers for vital yet commonly overlooked loadbearing components such as the yaw gear – these simple changes have a significant effect on failure rates for aging assets but can be considered ‘low hanging fruit’, offering high return on investment.
At this stage of a project’s life, the productive capabilities of the assets are well known. There is very little uncertainty in terms of wind forecasts, and operations teams will have significant experience with the technology. Using digitalisation, the other uncertainty, unplanned operations and maintenance costs, can be significantly reduced. Digitalisation and advanced analytics can reduce the operating costs of older machines, keeping a wind farm running without major upgrades for longer.
Predictive maintenance can reduce maintenance costs by 30 per cent, and total opex costs by up to 17 per cent. Potential problems can be detected with lead times of up to 24 months, enabling site managers to streamline logistics and procurement processes, reducing time on turbine for technicians and reducing the need for crane hire. Procurement of parts for older, often obsolete turbine technologies is also made easier with advanced lead time.
Predictive maintenance can also be used to ensure safety when running older assets beyond their original design life. Although life extension assessments of structural components are undertaken by owners, these often come with some uncertainty, as the required input for such assessments is often limited due to the age of the technology. Retrofitting condition monitoring systems for the surveillance of structural components will not only make a difference to operations and maintenance expenditure but will provide vital reassurance against unexpected catastrophic failures.
Digitalisation’s potential to overcome a lack of historical data is not limited to structural components. Investing in data capturing systems ahead of time will provide essential information about reliability and operating conditions to support life extension planning such as opex modelling, contractual negotiations, supply chain analysis and equipment upgrades.
Investing in a green future
Life extension plays a key role in effective, long-term digitalisation strategies, and an important part of supporting the UK’s 2050 net zero commitments. By modernising aging fleets and using the latest machine learning technology in tandem with engineering expertise, the wind industry in the UK will continue to drive the cost of production down while continuing to improve environmental outcomes.
Ultimately, healthier assets with longer lifetimes prevents wasteful damage and unnecessary replacements. This is vital to unlock further investment in wind energy. If investors can use digitalisation to run their projects more profitably, then they will have more capital to invest in future and be better inclined to support more wind projects.