Wind turbines are often erected in remote areas of the world, off shore or in mountainous regions, to exploit better wind resources. In these areas, the cost of failures and repairs can be substantial, and increase the levelized cost of energy (LCOE) remarkably. Since blade failures due to lightning are known to cause the longest outage time and involve the largest repair cost, ensuring the lightning performance of the turbines and especially of the blades has become very important.
Modern wind turbine blades are to a large extent manufactured using Carbon Fiber Reinforced Polymers (CFRP) structural parts, due to the CFRP’s excellent mechanical tensile strength and stiffness, combined with a light weight. The use of CFRP decrease the weight of the overall rotor, and hence reduce the requirements for the remaining structure (drivetrain, nacelle structural parts, tower, foundation, etc.). By reducing all loads on the structure, the cost of the installed capacity can be minimized (CAPEX).
However, CFRP also exhibit highly an-isotropic electric and thermal conductivities, which require special attention in terms of lightning protection. The specific issues of concern include design of electrical bonding to CFRP, investigation of damage tolerance, resin chemistry to optimize thermal and electrical properties of the CFRP, guidelines on overall protection concepts, etc. The research project SPARCARB is dedicated to solve these challenges of enabling efficient lightning protection of wind turbine blades using these CFRP based materials.
Once the complete knowledge on the interaction between lightning and CFRP is achieved, and the knowledge is built into design guidelines and paradigms for blade manufacturing, blades can be designed to lower both CAPEX and OPEX of wind turbines. The reduced CAPEX will make future investment in wind plants more attractive, and the reduction in OPEX will ensure that the business case for investors remains attractive for the lifetime of the turbines. Both are important to ensure integration of more green energy into our system, and SPARCARB will via the generated knowledge assist in this process.
