Researchers in South Korea develop groundbreaking technology to protect offshore wind turbines from rare but powerful positive lightning strikes.
A team at the Korea Electrotechnology Research Institute (KERI) has developed a receptor technology to safeguard wind turbine blades from damage caused by positive polarity lightning. This development addresses a critical challenge in renewable energy infrastructure, particularly offshore wind farms vulnerable to lightning-induced failures during winter.
While most lightning strikes are of negative polarity, positive polarity lightning—though less common—carries significantly higher current intensity and poses greater risks. These strikes primarily occur in winter, when cloud altitudes are lower, and are more likely to bypass conventional air-termination systems on wind turbines. “Positive polarity lightning has highly irregular patterns and requires advanced protective measures,” explained Dr Woo Jeong-min, the project lead.
Offshore wind turbines face heightened exposure to such strikes due to their isolated locations and towering structures. Traditional lightning rods fail to adequately protect against positive polarity strikes, which often target the side edges of turbine blades rather than their tips. This vulnerability leads to blade damage, operational downtime, and costly repairs. Industries relying on offshore wind farms, including renewable energy companies, power utilities, and infrastructure operators, are likely to benefit from this breakthrough technology. Its application could also extend to other lightning-prone areas, such as communication towers and offshore structures.
To tackle this issue, the KERI team analysed the interaction between lightning polarities and blade conditions. Using scaled models and artificial lightning experiments, they identified specific vulnerabilities in blade design. High-resolution imaging and simulation tools revealed that positive polarity lightning avoids the air-termination at the blade tip, striking the negatively charged middle section instead.
The innovative edge receptor technology optimally redistributes charges along the blade’s edges, enhancing resistance against positive lightning. Rigorous testing confirmed its effectiveness in minimizing damage. “KERI is the only institution globally to successfully develop and validate countermeasures for positive lightning on wind turbine blades,” said Dr. Woo.
This research promises to increase the resilience of wind energy systems. KERI aims to refine the technology, apply it to full-scale turbines, and continue expanding its scope to support the growing renewable energy sector.
