Reducing LCOE through innovation in the design of the pitch control system

Introduction

Recent investment trends in the power generation industry show that there is a healthy competition between solar and wind to attract investment dollars for new capacity. Globally, in 2015 the wind industry attracted $110B in investments for new capacity addition compared to $161B that was invested in solar based power generation. Levelized Cost of energy (LCoE) will be one of the key metrics that the asset owners will be using to make the choice between generation sources. It is critical for the wind industry to constantly innovate through design optimization and technology enhancements to reduce the LCoE. The pitch system is a major component contributing to turbine failure and downtime. This paper analyzes and demonstrates how an innovative design concept can help improve pitch system reliability and thereby reduce scheduled and unscheduled O&M expenses. The paper further establishes the link between the design improvements with reduction in LCoE.

Approach

a. Interview top 10 global wind turbine manufacturers (OEMs) to understand and map industry pain points
b. Benchmark pitch system reliability by gathering and analyzing field data to verify current failure rate
c. Develop, test and validate multiple innovative technology options to optimize pitch system design for reliability improvements
d. Use industry standard models of capital expenditure (CapEX) and operational expenditure (OpEX) to measure the reduction in CoE due to technology enhancements


Main body of abstract

Expiration of subsidy programs and changing policy frameworks are presenting a number of challenges for wind industry stakeholders These challenges, coupled with the fact that other renewables like solar are becoming more economical, have created an environment in which wind has to be more competitive if it is to survive and grow. As a result, reducing LCoE will be critical to ensuring the long-term success of wind projects in the future. New technologies will play a pivotal role in achieving this.

In recent years, significant advances in wind turbine technology have allowed manufacturers to reduce cost of energy through advancements in automation and electronics, blade tip extensions, etc. Pitch system is one area which can contribute to significant reductions in LCoE.

Typically, pitch systems account for less than 3% of a turbine’s total CapEX cost, and because of this, the true impact they have on turbine reliability and uptime has not yet been fully realized in the industry. In the past, OEMs have largely been focused on the optimization of bigger ticket items such as gearboxes and rotor blades; however, given the high percentage of downtime that is a direct result of pitch system failure, improving their performance and reliability has become increasingly difficult to ignore.

Conventional pitch systems used in many of the world’s wind turbines today consist of over 3,800 parts/components, and it is largely because of their complexity that they account for nearly a quarter of all failures in turbines. By optimizing the design and reducing the number of parts to just over 600, probability of component failure can be reduced significantly to ultimately improve the overall reliability of the turbine. An analysis based on the DNV GL cost modeling tools OMCAM and Turbine.Architect suggests that improvements in pitch system reliability from a standard industry design to a highly optimized one can result in reductions in LCOE of USD 0.89 per MWh.


Conclusion

- Reducing LCoE is important to the wind industry.
- Though pitch system is not a major cost component in a wind turbine, it is a major source of turbine failure and downtime.
- Technology can help improve pitch system reliability by **%
- Pitch system reliability can account for differences of up to * % in wind farm availability, **% in wind farm annual OPEX and * % in CoE.


Learning objectives
•Industry investment trends and importance of a reducing wind turbine Levelized Cost of Energy
•Wind turbine component (pitch system) reliability and its impact on turbine downtime, availability and cost of energy
•Increasing uptime and reducing O&M expense through innovation, technology and design optimization