BLADE RUNNER

PP Techniq

Wind power is a highly innovative industry where a significant proportion of company revenues is invested in research and development. Whilst a great deal is invested into the design of turbines to increase their energy generating capacity this has set a trend for ever larger turbines and presents challenges in keeping them operational. Endeavour Magazine looks behind the scenes at advances in wind turbine maintenance to keep the blades turning.

Wind power is one of the fastest growing energy sources in the world. In the EU alone investment in new wind farms exceeded €13 billion during 2010 with almost 20% of all new energy electricity generating capacity now coming from wind power both on and offshore. There can be little doubt that this is a large and growing market but an often overlooked issue relates to the maintenance of existing wind turbines. The design, construction and material composition of wind turbines has changed dramatically since the first utility scale wind farms were developed in the late 1970s and all turbines must be maintained and repaired in the event of failure. From a financial perspective it is imperative that wind turbines are kept operational at all times but in some cases shutdown becomes unavoidable. Wind turbine blades are ever increasing in size with rotor diameters now reaching

over 150 meters for the largest of turbines and historically repair and maintenance of these blades has been a major task. Often the repair of wind turbine blades will involve complete removal of the hub and bringing the blades to ground by crane which presents more challenges when turbines are situated offshore. This is extremely capital intensive in a market where cost control is of absolute importance.

PP Techniq, founded in 2003 by inventor and current director Paul Teichert, is a company established to develop advanced and cost effective applications for the wind energy sector. The company specialises in the development of new technologies and innovative use of materials by working alongside a range of leading specialist consultants and technology partners.

The flagship innovation from PP Techniq is the “FF360” blade guided access and maintenance platform which allows safe 360 degree access to wind turbine blades. The system allows access for two workers who can adjust their position in relation to the wind turbine blade to perform maintenance and inspection duties from a safe and stable operating platform. The system can also be used to carry equipment for scanning, cleaning and surface treatment meaning that most maintenance duties can be performed with little disruption to turbine operation. Gert Vinther Knudsen, Project Manager for PP Techniq explains:

“O ne of the main challenges the wind industry faces is how to set up a programme for regular inspection and overhaul of the blades (one of the most important and expensive components on a wind turbine) to ensure maximum output and to minimise costs and downtime throughout the turbine´s full lifetime.

“There is a need to access the installed blades in a cost effective way for inspection, surface treatment, cleaning and repair due to damages caused by handling and production failures and due to impact by hail, rain, salt, lightning etc. The blades are working under extreme conditions at very high speed! Furthermore there is a need to access the blades for aftersales activities to optimise the blade´s aerodynamics to increase output.

“These challenges will only increase with time as blades are going to become increasingly large and increasingly more advanced and will be installed in large numbers on huge turbines both on- and offshore.”

“The Blade Guided System makes it possible to access rotor blades independent of distance from tower to blade, length of blade, height and type of tower. Due to the controlled grip on the blade the platform is serving as a safe and calm working platform even when there are sudden changes in wind speed

PP Techniq

and direction. Furthermore only by being in firm contact with the blade the exact position of the technician and/or equipment can be fully controlled. Thus the technicians can focus on doing the work in a safe and fast manner, to keep downtime at a minimum.

“The Blade Guided System will be the ideal carrier of tools and robots to carry out semi or fully automated process on blades such as surface treatment, cleaning, inspection and NDT (non-destructive testing).

“From our perspective; alternative solutions such as tower based solutions, rope access, baskets hanging in a crane etc. will soon come to their limit due to the obvious challenge to access the increasingly larger blades. “

The ideas behind the Blade Guided System have been patented worldwide.

“Today we have realised the Blade Guided System in our FF360-platform which has been type-certified according to CE regulation for use on-shore. Furthermore we have made design studies on alternative Blade Guided solutions to be developed according to customers specific needs. “

The versatility and ease of rigging for the system also helps to minimise the time a turbine is taken out of operation and helps improve productivity as maintenance duties are carried out.

Recognising the potential of a sophisticated, reliable and fast working platform for wind turbine maintenance Force Technology has worked in close collaboration with PP Techniq to adapt a compatible non-destructive testing system used to analyse blade condition. Force Technology has extensive experience in non-destructive testing methods including development of lightweight and compact ultrasound scanning systems which allow detailed analysis of surfaces and internal structures. The Force Technology in house developed “P-Scan” testing equipment allows fully automated inspection of the blade surface and internal structure enabling assessment for wear, fatigue or damage.

“Our concept has been designed to support the use of automated equipment for maintenance work and Force Technology is a leader in providing on-site automated

scanners for non-destructive testing of wind turbine blades but the challenge for them is finding ways in which scanners can be used along the length of the blade itself. Through adapting a scanning system to work with the blade guided system we have been able to provide a platform which allows for constant and stable scanning across the entire length of the blade.”

Non-destructive testing methods have proven to be highly effective as a preventative measure to avoid down time in wind turbine operation by allowing potential blade failure problems to be identified and rectified as early as possible as part of a regular maintenance and inspection programme, the platform developed by PP Techniq also means maintenance work can be performed quickly with minimal disruption.

“The key focus remains on preventative testing. Even under normal conditions blades are subjected to high levels of stress. For example a wind turbine blade operates at 350 kph and at this speed even small particles in the air will have an abrasive effect on the blade surface. This abrasive effect causes wear to the blade and means regular testing and maintenance of the blade surface is very important to prevent further damage which over time could lead to failure.”

Today, in a challenging international economic environment, wind energy is coming under intense scrutiny and governments must demonstrate careful planning and budgetary control when formulating energy policy, the industry must do what it can to enhance the productivity and cost effectiveness of wind power. It is undisputable that investor confidence remains in wind power with the sector contributing a total of €32 billion to EU GDP during 2010 and creating 30% more jobs when EU unemployment rose by 9.6%. In order for confidence in the industry to be maintained it is vitally important that operational wind farms are as productive as possible and down time is kept to an absolute minimum. Innovations such as those demonstrated by PP Techniq and Force Technology go a long way in improving the efficiency of wind turbine maintenance and such effective use of technology can only contribute to the long term prosperity of the industry.

PP Techniq

Blade Guided SystemSolving the challenge to access installed rotorblades in a safe and fast manner to keep turbine downtime at a minimum. Independent of distance from tower to blade, shape and length of blade, height and type of tower.

PP Techniq ApSNordborgvej 81DK-6430 NordborgDenmark

info@pptechniq.com+45 74887288www.pptechniq.com

PP Techniqwww.pptechniq.com+45 7488 7288

Written by Martin White

www.littlegatepublishing.com