The Case For Surge Protection Systems For Wind Turbines

The continual change in climate conditions combined with the increasing dependence upon fossil fuels has provided a great in interest in sustainable, renewable energy resources worldwide. One of the most promising technologies in green energy is wind power, which except for high startup costs would be the choice of many nations worldwide. For example, in Portugal, the wind power production goal from 2006 to 2010 was to increase to 25% the total energy production of wind power, a goal which was achieved and even surpassed in later years. While aggressive government programs pushing wind and solar energy production have expanded wind industry substantially, with this increase in the number of wind turbines comes an increase in the likelihood of turbines being struck by lightning. Direct strikes to wind turbines have become recognized as a serious problem, and there are unique issues that make lightning protection more challenging in wind energy than in other industries.

The construction of wind turbines is unique, and these tall mostly-metal structures are very susceptible to damage from lightning strikes. They are also difficult to protect using conventional surge protection technologies which mainly sacrifice themselves after a single surge. Wind turbines can rise more than 150 meters in height, and are located typically on high ground in remote areas that are exposed to the elements, including lightning strikes. The most exposed components of a wind turbine are the blades and nacelle, and these are generally made of composite materials which are unable to sustain a direct lightning strike. A typical direct strike generally happens to the blades, creating a situation where the surge travels all through the turbine components within the windmill and potentially to all electrically-connected areas of the farm. The areas typically used for wind farms present poor earthing conditions, and the modern wind farm has processing electronics which are incredibly sensitive. All of these issues make the protection of wind turbines from lightning-related damage most challenging.

Within the wind turbine structure itself, the electronics and bearings are very susceptible to lightning damage. Maintenance costs associated with wind turbines is high due to the difficulties in replacing these components. Bringing technologies which can improve statistical averages for necessary component replacement is a source of great discussion within most board rooms and governmental agencies involved with wind production. The robust nature of Raycap’s Strikesorb surge protection product line is unique among surge protection technologies because it continues to protect the equipment even when activated, and there is no need for replacement or resetting after a lightning surge. This allows wind power generators to remain online for longer periods. Any improvements to the statistical averages of offline statuses and times that turbines are down for maintenance will ultimately bring further costs to the consumer.

Preventing damage to low-voltage and control circuits is crucial, as studies have shown that more than 50% of wind turbine failures are caused by breakdowns of these types of components. Documented breakdowns of equipment attributed to direct and induced lightning strikes and backflow surges which propagate just after a lightning strike, are common. Lightning arrestors installed to the power grid side of systems are grounded together with the low voltage side in order to decrease grounding resistance, increasing the ability of the entire chain to withstand a strike to a single wind turbine.

Raycap’s Strikesorb technology, combined with the traditional elements associated with lightning suppression, presents the best scenario for prevention of lightning surge damage to wind farms over time. While the unique aspects of a wind turbine itself make it difficult to foresee a future without the discussion of lightning damage, the prevention of surge related damage through the use of maintenance-free Strikesorb industrial SPDs will help wind power to stay online and compete with fossil fuel energy as a viable source of green and sustainable power.