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Assessment of more than 160 MW of Retrofitted Wind Turbines

When several clients who operate wind farms on the German island of Fehmarn in the Baltic Sea required assessments of their retrofitted wind farms to ensure conformity with grid code requirements, a thorough analysis in compliance with relevant regulations was necessary. That is why FGH, a cooperation partner of TÜV Rheinland, was the right choice for the project, by virtue of its expertise in grid code compliance checking.

Basic Facts
Client: - Windpark Klingenberg GmbH
- Windpark Fehmarn Mitte GmbH & Co. KG
- Windkraft Presen GmbH & Co. KG
- Bürger-Windpark-Westfehmarn GmbH
- Windpark Fehmarn Nord-West Verwaltungs GmbH
- Fehmarn Netz GmbH & Co OHG
Timeframe:2009 - 2010
Project Location: Fehmarn, Germany
Main services:- Assessment of retrofitted wind farms
- Verification of conformance with SDLWindV for wind turbines
- Analysis of protection schemes - L0 and the reactive power capabilities
Involved regulations/standards:- EE G (Renewable Energy Law)
- EE G guidelines for generators on the high voltage transmission grid
- System Service Ordinance by Wind Energy Plants (SDLWindV)
- TransmissionCode 2007
- FGW technical guideline 8

Initial situation and requirements

The excellent wind conditions on the island of Fehmarn, Germany prompted the building of many wind farms there 15 years ago. Subsequent changes to the legislative framework and adoption of the System Service Ordinance by Wind Energy Plants (SDLWindV) in 2009 led the German government to offer incentives to wind farm operators to retrofit existing wind turbines and make them compliant with the advanced requirements of the grid codes for medium and high voltage regulations (Medium Voltage Directive and TransmissionCode respectively).

Wind farm operators who reinvested and upgraded their existing wind turbines receive a bonus payment for the energy they produce only after they successfully obtain confirmation of their grid code compliance.

About FGH and about TÜV Rheinland

About FGH:

Following a ninety-year tradition as the leading research association of Germany‘s electric power utilities and industry, FGH provides a full range of services for the integration of dispersed power generation units into the power grids. The FGH Certification Office, accredited for grid code compliance proofing, provides unit as well as project certificates for national and international grid codes.

An experienced partner like FGH enables TÜV Rheinland to offer clients a full-service one-stop shop solution for all wind energy projects.

About TÜV Rheinland:

Founded 140 years ago, TÜV Rheinland is a global leader in independent inspection services, ensuring quality and safety for people, the environment, and technology in nearly all aspects of life.

We inspect technical equipment, products and services, oversee projects and help to shape processes for companies around the world. Since 2006 we have been a member of the United Nations Global Compact to promote sustainability and combat corruption.

For the wind energy sector we provide a comprehensive service portfolio, covering every aspect of wind energy projects – from site selection, design and manufacturing support to dismantling plants.

Solutions, results

FGH is an accredited certification - L0 body and performed the technical assessment and respective analyses in this project to ensure the conformity and verify compliance of the wind parks with grid code requirements.

The main task of the project was verification of the requirements of SDLWindV for wind turbines that were commissioned between 2002 and 2008. The procedures used were based on the recommendations in Technical Guideline No. 8 (TR8) of the German Wind Energy Funding Association (FGW), which in fact were developed with substantial input from FGH experts. Apart from verifying the correct implementation and validity of reactive power under voltage protection, FGH also checked the active power reduction in case of over frequency.

In addition, a comprehensive analysis of the protection scheme and the reactive power capability was carried out, where the undersea cables to the island connecting it to the continental power system were taken into account. The retrofitted wind turbines of type ENERCON E70 E4 also received their unit certificates from FGH.

Read more about Wind Farm Certification - L0

Did you know?

On Fehmarn there are six wind farms connected to the medium voltage grid as well as five wind
farms with high voltage connection. With more than 70 wind turbines, the wind farms here
represent a total installed capacity of 168 MW.

Benefits for the client

FGH supported the various wind farm clients:

  • Comprehensive assessments of the electrical characteristics of the wind farms.
  • Extensive expertise in grid integration of renewable energy systems and reliable certification services as an impartial witness.