Improvement in capacity factor and fatigue assessment of VLMOS for wind power generation based on navigation simulation

The very large mobile offshore structure (VLMOS) for wind power generation is one example of challenging future technologies to create a new backbone of energy resource of our country. The National Institute for Environmental Studies Japan has been studying this concept and found that increasing the capacity factor and reducing the weight of the structure are keys to make this concept successful. We investigated the navigation logic to improve the capacity factor and performed a fatigue assessment to ensure the structural safety of light weight design. Taking the knowledge on the seasonal weather condition in the Pacific Ocean into consideration, improved strategy of the VLMOS navigation for maximizing the generating power is proposed. Navigation simulations show that it is easy to achieve more than 40% capacity factor and to escape from high seas. Using wind and wave data obtained from the navigation simulations, an assessment of the fatigue damage has been performed. It is stated that the structure has enough fatigue strength for a 100 years of operation even if wind turbines get more than 40% of the capacity factor.