Repowering a Wind Farm: The Key for Decent ROI
 Topic: extensions for renewable energy projects |  Read Time: 7 mins |
 Landowner type:Independent landowners | Institutional landowners | Professional advisers |  Energy: Onshore wind |
14th February 2025Is repowering a wind farm critical for seeing a decent return on investment? In this blog, I will explore the repowering process in detail and how it can benefit both developers and landowners.
When a developer builds an onshore wind farm in the UK, local authorities typically grant planning permission for a period of 20 to 25 years. This timeframe reflects the expected economic lifespan of onshore wind turbines, which is generally in line with the planning approval period.
At the end of this period, developers are usually responsible for decommissioning the turbines and restoring the land to its original state. Both wind farm developers and planning permission officers generally view this arrangement as reasonable, as it ensures the operational life of the wind farm corresponds with the duration of its approved planning permission.
However, wind turbine technology has become far more efficient over the years. As a result, developers are now exploring the option to repower their wind farms, allowing them to maximise their return on investment instead of decommissioning still-viable projects.
Repowering typically involves replacing older turbines or relocating them within the site. However, developers wouldn’t technically be decommissioning the entire project, as the wind farm remains operational with enhanced performance.
But how viable is repowering a wind farm? Is it a good deal for landowners or only designed to benefit developers? Whether you’re curious about the repowering process or are on the cusp of negotiations, this blog covers the key things you need to know.
What Does Repowering a Wind Farm Mean?
The ‘repowering’ of a wind farm means extending the life of existing turbines or replacing and repositioning them.
This definition was solidified during a landmark case in 2019 that involved Kirkby Moor Wind Farm in the Lake District.
The case determined that planning applications for the ‘repowering’ of wind farms would face less stringent requirements than those for new onshore wind farms. The case also confirmed that existing wind farms seeking to extend their existing planning permission would not be required to obtain the backing of their local community.
Equally, existing wind farms wouldn’t need their local authority to formally recognise their site as being located in an area suitable for wind energy development.
These factors are unlikely to bear much relevance after Labour’s removal of the de facto onshore wind ban in 2024. But it’s worth noting that repowering a wind farm usually faces less resistance than building a new one.
What happens during the process?
During the repowering process, a developer will assess new turbine models and blade designs to determine the best fit for the site. They’ll also check the capacity and condition of existing grid connections to ensure they can handle increased energy output.
Like on any wind project, developers must still adhere to their region’s height and visual impact restrictions. They’ll also need to update any Environmental Impact Assessments to evaluate impacts on wildlife, noise and landscapes. These factors may have changed since the developer first mounted the project, so it’s important to reassess these things before moving forward.
The developer will then decommission the old turbines once the local authority green-lights the repowered project. This process involves removing existing turbines, foundations and electrical components from the site.
UK regulations promote recycling and sustainable disposal, especially for blades and other non-recyclable components. So, developers should abide by this when and where they can.
After the developer decommissions the old turbines, they’ll work on replacing old turbines with newer, more powerful models. They may also need to reinforce or replace any foundations and upgrade the site’s electrical connections to accommodate a higher potential output.
Finally, they’ll test the turbines to ensure they integrate smoothly with the National Grid. From there, the focus shifts to optimising energy output and monitoring turbine performance to catch any issues preemptively.
Why Is Repowering a Wind Farm Now a Better Option Than Decommissioning?
As I mentioned earlier, wind turbine technology has improved significantly over the years.
A clear example of this is the UK’s 715 per cent increase in electricity generation between 2009 and 2020. Much of this is down to improvements in wind turbine materials and design over the same period.
For instance, hub height has increased an impressive 66 per cent since 1998, and modern turbines are now better equipped to handle higher wind resistance.
In addition, most turbine manufacturers now use glass and carbon fibre composite materials. These are usually lighter and more efficient than previous iterations. So, turbines are hardier overall.
As a result, it isn’t uncommon for today’s turbines to remain operational for up to 35 years (subject to adequate maintenance, of course). This extended lifespan makes repowering a wind farm a more attractive option than decommissioning.
Alternatively, if a wind farm has performed significantly worse than expected due to the premature failure of parts, the developer may choose to replace the turbines before the original planning permission expires. This allows the developer to continue operating the wind farm beyond the initial approval period and secure a more favourable return on investment.
Both options are valid reasons for repowering a wind farm, offering developers a better opportunity to recoup their investment and ensure long-term profitability.
What Might Repowering a Wind Farm Mean for Onshore Wind Farms In General?
Many onshore wind farms will likely be repowered over the coming years. This is due to our increasing need for clean and sustainable energy and to fulfill the UK government’s commitment to achieving net zero by 2050.
Data from the energy regulator, Ofgem, shows that the most significant increase in onshore wind farms occurred between 2004 and 2005, following the introduction of generous government subsidies.
With Contracts for Differences (CfDs) replacing the Renewables Obligation Certificates (ROC) scheme, new wind farms may become slightly less lucrative in the coming years. However, as the government keeps pushing for clean energy with the Great British Energy initiative, it’s hoped that more support will be offered to repower projects in the future.
My Recommendations for Developers and Landowners
Before I round off this blog, let’s walk through the exact considerations you’ll want to consider before repowering.
For landowners
Lease agreements
Repowering a wind farm offers the perfect opportunity to review your existing contracts.
It’s wise for landowners to evaluate whether their existing lease agreements with developers need to be updated for the repowered site. With increased turbine height and energy production, this is particularly important, as the site will naturally produce more income.
I always advise doing plenty of research on current market rates on similar sites across the country. After all, the industry will have moved along considerably since the developer first built the site. So, you must seek fair compensation that aligns with the increased revenue from the upgraded turbines.
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Land use and infrastructure considerations
Landowners should have detailed discussions about the larger equipment and vehicles required for the repowering process. While this doesn’t require extensive negotiation, it’s important to recognise that site access will look slightly different for new, larger turbines.
For developers
Engage with Great British Energy
In my rundown of British party policies, I’ve discussed Labour’s new Great British Energy (GBE) initiative in detail. This aim to make Britain more energy independent could be extremely useful for developers who wish to repower an existing project.
While there’s a big push to double onshore wind energy capacity by 2030, there are also likely to be policies in place for repowering. If a wind farm still has life left in it, it makes little sense to decommission it.
It’s worth sitting tight for further news on GBE to make repowering easier and more affordable.
Think ahead and upgrade early
While repowering can be costly, it’s an excellent long-term investment. As I have discussed, modern wind turbines have become more efficient, with longer blades that can capture significantly more wind.
Getting a jump-start on the repowering process could help you produce more energy in the twilight years of your lease.
It’s also worth noting that replacing unreliable turbines with more durable models maximises efficiency and avoids costly breakdowns. This puts you ahead of the game and prevents your project from being out of action for too long.
Collaborate locally
It’s unfortunate, but not everyone is in favour of wind turbines in their area. However, you can boost the popularity of your project by engaging with communities through Labour’s Local Power Plan.
Although in its early stages, this plan is set to promote shared ownership and financial benefits, fostering goodwill and long-term support for your repowered wind farm.
Should Planning Permission Be Extended Beyond 25 Years and Repowering Encouraged?
To answer this question, I’ve reviewed the financial accounts of onshore wind farms commissioned in 2004/5. From this data, I noted it took developers an average of two and a half years from receiving planning permission to when the wind farm became fully operational.
Furthermore, I found that it took most developers an additional 15 years to fully recover their initial investment after their wind farm started generating electricity. This means it took the developers of these onshore wind farms 17.5 years from the date of receiving planning permission to start making a profit from the sale of electricity.
Many of these wind farms are now approaching the end of their original planning permissions and will have only been profitable for 2.5 to 7.5 years (i.e., between 12.5 per cent to 30 per cent) of their 20 to 25-year lifespan.
Given this data, most developers will be desperate to extend the planning permission and repower their wind farms. These extensions will allow them to achieve a more satisfactory return on their original investment by operating beyond the limited period of profitability available.
Now, when considering profitability, both developers and landowners should factor in the falling costs of wind turbines and efficiency improvements. However, with the removal of government subsidies, developers now face a narrower window of opportunity to recoup their investments. This could all change if the guaranteed period of planning permission is extended beyond 25 years.
Final Thoughts
Landowners who have made their land available for wind farms should actively support extending the life of existing wind turbines. Alternatively, they should encourage their developer to replace unreliable wind turbines with more durable and efficient models as soon as possible.
If these steps are taken, wind turbines will provide landowners with a stable and diversified source of income. In my opinion, this is especially needed in these challenging economic times.
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