Reducing the Financial Impact of Lightning Strikes
Wind is a key pillar of the growing American renewable energy industry. But, with just 8.4% penetration at the start of 2021, we have a long way to go to meet the DOE’s goal of 20% by 2030 and 35% by 2050. To increase adoption and hit these targets, the price of wind energy must drop significantly in the next several years. The wind industry has already seen more than a 40% cost reduction since 2010. The question is, how does the industry continue to reduce costs?
One way is to reduce the financial impact of lightning strikes.
Lightning can cause catastrophic damage to wind turbine blades and other components. It can also result in blade skin punctures, shell delamination, split trailing edges, and other damages that are costly to repair. Even with the current mitigation systems in place, it’s estimated that lightning damage costs the wind industry more than $100 million each year. Strikes are inevitable, and their numbers will only grow as turbines get taller, more on and off-shore wind farms are developed, and our climate continues to change. That’s why the technologists at Arctura are developing a proprietary coating that reduces lightning damage to turbine blades by encouraging surface flashovers.
Our coating is called ArcGuide™ and it’s similar to a segmented diverter, which is a technology originally developed for the aviation industry. Segmented diverters have a strip of conductive elements on an adhesive substrate. When pre-strike streamers form, an ionization channel is created above the adhesive strip that ultimately diverts the energy to the ground. While certainly a step in the right direction, there are a number of challenges with these diverters for wind. First, the conductive elements are on the surface of the blade, making them prone to erosion from wind and rain. The harsh environment can also degrade the strip’s adhesive to the point that it falls off. This means that within the first year, the efficiency provided by a segmented diverter can be significantly reduced. The on-blade placement also increases drag, which decreases power generation. This makes the segmented diverter a costly solution for something that will likely need to be replaced.
Expanded metal foil (EMF) products are also used by the wind industry for lightning mitigation. Made with copper or aluminum, EMFs are integrated into the composite of the blade. However, as with segmented diverters, this technology is costly in part because of the precision manufacturing required to cut and stretch the metal. Also, strikes often damage the EMF itself resulting in drag and eventually expensive and time-consuming repairs.
The team at Arctura set out to solve the challenges presented by both segmented diverters and EMF products, ultimately providing a more cost-effective solution to lightning strike damage. Our proprietary blade coating does just that. ArcGuide™ uses discrete conductive elements that are mixed with an industry-standard topcoat paint and applied to the blade near the lightning receptors. Because the conductive elements are imbedded in a smooth topcoat, there are no erosion or drag issues. Our raw materials are inexpensive, and unlike segmented diverters and EMF, our process doesn’t require precision manufacturing, resulting in what is expected to be ArcGuide’s significantly lower price point as compared to products currently on the market.
Founder and CEO Neal Fine monitors a test of ArcGuide™, Arctura’s proprietary blade coating designed to reduce the financial impact of lightning strikes.
All of these factors result in a blade coating that is a significant improvement to traditional lightning protection systems (LPS). With a traditional LPS, damage occurs when the lightning attaches directly to the down conductor or other metal components inside the blade, rather than the receptors built into the surface. But with the ArcGuide™ coating, ionized channels are formed in the air above the surface of the blade, safely transmitting the energy to the ground and reducing the frequency of punctures and other damage caused by lightning strikes. This improves the performance of the existing LPS without requiring costly redesign. Because of this, we believe that our technology will reduce O&M costs, extend blade lifetimes, and reduce turbine downtime – and that equates to lower wind energy costs and an increase in the amount of wind energy sent to the grid.
Contact Arctura today to learn more about ArcGuide™ and other exciting innovations our team is bringing to the wind industry. If you own and operate a wind farm, we would be excited to talk to you about a potential pilot project as we roll out the ArcGuide™ product in 2022.
