5 ways to optimise wind farm performance
Guest post by David Cunningham, cleantech and renewables analyst at SgurrEnergy.The wind market is maturing, which means owners and operators are increasingly looking to enhance returns by managing their assets more effectively.
At the same time, we are also seeing projects built with higher hub heights and with larger swept areas, where the relationships between the wind and the turbine are not yet fully understood. As a result, there is a drive to mitigate risk and deliver optimal financial performance at both ends of the wind farm development life cycle.
And, if that was not challenging enough, developers are also under pressure to reduce the levelised cost of energy from new projects.
Over the design life of a wind farm, making minor adjustments to the operation of that asset can make a big difference to its financial performance. With that in mind, here are five methods to optimise wind farm operation and financial performance using a combination of modern technology and industry-leading analytical techniques.
1. Fix yaw misalignment
Turbines must directly face the wind to maximise the power they generate, but this often does not happen due to shortcomings of traditional wind direction measurement techniques. Owners can address this by using lidar to measure wind speed and direction across the whole rotor area to allow for optimal turbine positioning.
By implementing more effective measurements this can push up annual energy production (AEP) by 2%, and raise the absolute project internal rate of return (IRR) by 0.3%.
2. Make aerodynamic improvements
Vortex generators are small fins that help to improve blade performance by reducing flow separation and improving lift. The use of effective scanning technology means owners can apply vortex generators in an optimum manner to match real site conditions.
This can increase AEP by an estimated 2%-3%, with a boost of 0.3%-0.4% to IRR.
3. Control and pitch optimisation
Effective individual blade control can be vital to ensure the wind turbines meet their design life in addition to improving energy output. Importantly, as wind turbines age and degrade, their optimum control set-points also change over time. By incorporating a more robust and adaptive turbine control system, we can assist in dealing with off-design wind characteristics and changes in blade surface conditions.
This can increase AEP by 1%-4%, and project IRR by 0.1%-0.6%.
4. Forestry restructuring
Locating a wind farm near a wooded area will clearly have an effect on turbine performance, but the exact effect is difficult to quantify. With the benefit of scanning lidar, developers can best understand the real effects of forestry on project performance — and use this to manage the environment around a wind farm more effectively through selective forestry felling and restructuring.
This can boost AEP by up to 15%, delivering an increase in the project IRR of up to 3%.
5. Wind farm control
We know that wakes from one turbine can have an impact on others, but too often developers monitor and manage each turbine separately. If developers can control the wind farm as a single unit then this would deal with wake effects in real time, and provide grid support to meet regulatory requirements.
This can boost AEP by 1%-4%, and increase IRR by 0.1%-0.6%.
These optimisation results are based on client projects and verified by rigorous before and after tests and measurement. The individual improvements may seem incremental, but in combination these add up to a substantial improvement in the performance of projects.
We are already applying these five techniques to deliver increased returns on investment for wind farms globally. Further commercial gains are expected from a reduction in operating costs, particularly in the rotor blades, as well as the drive train and gearbox.
In our view, adopting optimisation activities enhances developer, investor and owner returns at every stage of the development cycle and should form a core part of M&A, design and operational activity.