Project: Smart Embedded Sensor System

The aim of the Smart Embedded Sensor System (SESS) is to provide the wind turbine industry and wind turbine users and operators with an effective tool for anticipating structural damage and extending the service-life of wind turbine blades. The expected technological result will be a device consisting of an array of piezo-based transducers that will be embedded either directly on the wind turbine blade or inside the wind turbine blade, and will detect internal damages in the blade by means of analysis of surface ultrasonic Lamb waves produced and sent out over multiple wave modes and wavelengths, as well as by detecting vibrations and other conditions which may arise in the structure of the blade. The rotor blade, which is the most vulnerable part of a wind turbine [1] requires comprehensive analysis due to its complex, multi-layered structure. The SESS will be able to respond and detect flaws which are caused either by loading, unforeseen conditions or by the inherent characteristics of the blade itself (i.e. manufacturing flaws)._x000D_A dedicated structural health monitoring system for wind turbine blades is at present not available on the market, which means that producers and operators need to compensate for this during the design process (i.e. large safety margins) and/or through COtenance scheduling at regular intervals, which may be costly and may not be reliable or accurate due to incomplete or non-current knowledge. This has been recognized not only in the science community, but also by key industry stakeholders, such as the European Wind Energy Technology Platform's Working Group "Wind Power Systems" which stated in May 2007 that "as reliable monitoring systems for early failure detection and accurate interpretation of signals are not yet available, R&D in this area is urgent. In particular access technologies for offshore and remote terrain applications are crucial in bringing the availability to acceptable levels"[2]. The Working Group "Offshore Development and Operation" also outlined a similar need, specifically for offshore sites [3]. _x000D_The context for the need for a cost-effective and reliable structural health monitoring solution should be looked at from a number of perspectives, these being: 1. the COtenance cost and power output lost as a result of interruptions in the operation of wind turbines 2. the backlog in component parts 3. the ever increasing burden on wind energy as the key source of alternative energy in Europe and the steady growth in power capacity of wind turbine farms in Europe. _x000D_1. Wind turbine blades are a significant cost during the lifetime of a wind turbine - 30% of the life-cycle costs are attributable to them, while they also contribute to 34% of the overall system downtime [4]. Studies have shown that replacing a set of turbine rotor blades costs 15-20% of the original turbine investment, while the annual repair and COtenance costs vary from 1.5-2% of the wind turbine price with new-generation wind turbines, and up to 3% in the case of older-generation wind turbines [5]. A recent study, which developed a mathematical model for quantifying the cost-effectiveness of condition monitoring systems showed substantial long-term benefits, especially for small and mid-sized wind farms [6]. The SESS, because it will offer on-line, real-time monitoring will make operations and COtenance activities on the blade a more analysis- and knowledge-based activity, and thereby drastically reduce the probability of oversight and subsequent, irreversible damage to the wind turbine blade._x000D_2. The current problem facing the wind turbine industry - a considerable shortage in the supply of component parts[7], highlights the need for predictive and preventive COtenance. The SESS by providing a knowledge tool will help operators make more informed purchasing and O&M decisions and become less dependent on supply-side shortages._x000D_3. In the past 5 years, 30.9% of all new electricity generation projects in Europe were wind power-related [8]. The investment in wind power will continue to increase in the wake of the EC's Energy Green Paper which calls for a binding goal of 20% of energy supply from renewable energy sources by 2020. Wind power's share in the renewable electricity generation with 16,3% was second only to hydraulic power in 2005 [9]. To continue the trend of wind energy growth in Europe and beyond, it is necessary to look at measures which will make this power source more competitive and the SESS is a potentially very useful solution. The operating power capacity in Europe has increased from 34.4 GW in 2004 to 40.5 GW in 2005[10]. The project consortium consists of 3 SMEs (Noliac, EC Electronics, IP), which are seeking to gain entry in the highly niche SHM/NDT market, a research institute (Risoe/DTU) which has done extensive work and possesses invaluable knowledge about wind turbines, and an association which brings together potential end-users (Estonian Wind Power Assoc.)

Acronym	SESS (Reference Number: 4410)
Duration	01/01/2009 - 30/09/2011
Project Topic	The SESS will aim to provide the wind energy sector with a cost-effective monitoring device and analytical tool for locating and changes in turbine rotor blade structure. The innovative aspect of SESS lies in the dual active/passive detection method and a novel approach to damage detection analysis.
Project Results (after finalisation)	SESS prototype hardware (v1.0) in Denmark, Estonia, and Poland
Network	Eurostars
Call	Eurostars Cut-Off 1

Project partner

Number	Name	Role	Country
6	EC Electronics	Partner	Poland
6	Eesti Tuuleenergia Assotsiatsioon	Observer	Estonia
6	Innowacja Polska	Coordinator	Poland
6	NOLIAC A/S	Partner	Denmark
6	OU ELIKO Tehnoloogia Arenduskeskus	Partner	Estonia
6	(Risø-DTU) National Laboratory for Sustainable Energy, Technical University of Denmark	Partner	Denmark