HOW OFFSHORE WIND CONCERNS THE SECURITY OF SUPPLY

Transcription

1 Public funding by Programme: Research for Civil Security Maritime Security Offshore Wind Energy Safety and Security HOW OFFSHORE WIND CONCERNS THE SECURITY OF SUPPLY Presentation at the International Conference & Workshop REMOO-2017 ENERGY FOR TOMORROW May 2017, VENICE / ITALY Dr. Jürgen Gabriel* and Dr. Karin Jahn Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM Bremen / Germany

2 The Fraunhofer-Gesellschaft Fraunhofer-Gesellschaft Fraunhofer IFAM Founded in institutes 24,500 employees R&D volume 2.1 billion Euro Founded in 1968, Fraunhofer institute since 1974 Bremen + Locations in Dresden, Oldenburg, Stade and Wolfsburg 609 employees total budget in Mio. Euro Fraunhofer 2

3 The OWISS-Project Offshore Wind Energy Safety and Security 2020 Research Programme for Civil Security Maritime Security Funding by Federal Ministry of Education and Research Project Aims Prevent / minimise disturbances in the operation of offshore wind farms (OWF) Protect the population from serious disturbances in the supply of electricity due to disturbances in the operation of OWF Affiliated partners University of Applied Sciences, Bremerhaven + Fraunhofer IFAM, Department of Energy System Analysis, Bremen German Offshore Consult GmbH, Bremen Institute of Shipping Economics and Logistics (ISL), Bremerhaven Institute for the Law of the Sea and International Marine Environmental Law (ISRIM), Bremen.plus associated partners from the industry and security authorities Project duration: For more Information: Source: DOC 3

4 Offshore wind farm grid connection Turbines generate mediumvoltage AC power Transformation to higher AC power at substation platform Conversion of AC power to DC power at HVDC platform Transport of DC power onto land via sea cable Conversion of DC power to high voltage AC power and feed into the onshore-grid Source: north-sea-learning-curve /featurenavigating-the-north-sea-learning-curve html and Siemens 4

5 Offshore wind energy categories of risks Categories of risks with regard to the security of power supply Lack of electricity production during periods without wind Volatility of electricity production Longer technical downtimes (compared to similar onshore events) Special offshore threats to safety and security extreme weather conditions unusually high waves lack of shelter insufficient protection against (terrorist) attacks Geographical concentration of central components of the offshore wind energy supply system (OWESS) 5

6 Offshore Wind Energy System critical elements Geographical concentration as special risk in 2020 Concentration of typical elements in the German North Sea Typical elements of the OWESS Maximum power of a single element Maximum power in the case of geographical concentration Wind turbine 5 MW 400 MW (wind farm) Substation platform (offshore) Submarine cable HVDC converter platform (offshore) HVDC converter station (onshore) Land cable 400 MW No concentration known 900 MW 900 MW 900 MW 900 MW Minimum distance of 100 m in the case of parallel cables So called parent/subsidiary arrangement with 1,800 MW Location with 3 elements (2,130 MW) realized, with 3 elements (2,700 MW) planned Cases of parallel arrangement of several submarine or land cables up to 3,000 MW realized 6

7 Our power supply system when is it at risk? Electricity grid: balancing of production and demand required in every second Germany needs daily maximum power of 40 to 80 GW (1 GW = 1 Mio. Kilowatt) Lack of up to 3 GW can be compensated in the EU transmission network within 30 seconds (3 GW = 2 large nuclear power plants) Lack of up to 6 GW can be compensated in the EU transmission network within 5 minutes Power supply Power balance = 50 Hz Power demand Source: 10/stromangebot-nachfrage_waage.jpg Installed power in the German OWESS 2020 (planned) all OWF in the German North Sea = maximum 5,700 MW = 5.7 GW all OWF in the German Baltic Sea = maximum 800 MW = 0.8 GW 7

8 Assessment scheme for the failure of power supply Two criteria Speed of drop of feed in of electricity Maximum loss of power Time span (t) between the occurence of the start event and the drop of the feed in of electricity to 0 MW t 30 sec. 30 sec. < t 300 sec. t > 300 sec. l < l 1,000 l > 1,000 Maximum loss (l) of power (MW) Evaluation of failure of power supply small medium large Source: Fraunhofer IFAM 8

9 Our power supply system when is it at risk? Examples for dangerous incidents Incident Explosion Short-circuit Fire Lightning strike with component failure or short-circuit Strong winds Oil release followed by a fire or by an explosion Expected speed of drop of power very quick very quick very quick (under appropriate conditions) very quick undefined; possibly foreseeable assumption: very quick slow reason: the formation of an ignitable fuel-air mixture takes some time 9

10 Result of the risk analysis Risk of large failure in power supply in case of geographically concentration of OWESS elements with high power converter submarine land converter platforms cables cables stations Some start events can provoke a very quick drop in power and have a high risk for the security of supply fire explosion short-circuit failure of sensitive components 10

11 Reducing the offshore risk for the security of supply Three strategies to reduce the risk Extension of the time available for reaction Reduction of the maximum load failure Redundancy of the particularly vulnerable components 11

12 Reducing the offshore risk for the security of supply Extension of the time available for reaction Multifaceted sensor systems allow the early detection of various hazards, for example approach of a disabled ship unauthorized entry deficiency in relevant plant components fire More time to inform the TSO and to switch off and compensate affected OWESS elements Source: / AP 12

13 Reducing the offshore risk for the security of supply Reduction of the maximum load failure Geographical de-concentration of identical OWESS elements But: Advantages of geographical concentration will be lost too! Adjacent converter platforms backup in case of technical problems, maintenance or repair works Adjacent submarine or land cables: organizational and financial advantages for planning, ground surveys and laying lower costs for the periodic survey of the position of submarine cables special challenge of crossing the UNESCO World Heritage Site Wattenmeer : geographic concentration of cables minimizes the ecological damage and disturbance of the site Adjacent converter stations: backup in case of technical problems, maintenance or repair works lower investment costs easier perimeter protection 13

14 Reducing the offshore risk for the security of supply Redundancy of the particularly vulnerable components (1) Actually most of the OWF are connected to the transmission grid by only one specific grid connection system (GCS) radial grid structure The failure of any single element of the GCS could shut down the whole GCS and stop the production of one or more OWF for several months 14

15 Reducing the offshore risk for the security of supply Redundancy of the particularly vulnerable components (2) A meshed offshore grid could provide redundancy Each OWF is connected to the transmission system via different GCS If any single element of the OWESS shuts down one GCS, power would be transported by another GCS 15

16 Summary Offshore wind energy presents only a minor risk to the security of electricity supply The TSO can cope with the failure of any single OWESS element Geographical concentration of identical elements of OWESS is a risk, if a single event simultaneously hits a group of adjacent elements There exist a number of strategies to reduce this risk One promising approach to reduce risks could be the installation of a meshed offshore grid This would provide redundancy of all OWESS elements The economic feasibility of this approach has to be analysed - both from the perspective of the society and from the perspective of the OWF operators 16

17 Authors Your questions are welcome! subsequently or later via to: Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM Wiener Straße Bremen 0421/