© ABB-EWEC 2006 ATHENS /03/06 EWEC 2006 Athens The Challenges of Offshore Power System Construction Peter Jones Lars Stendius ABB

© ABB-EWEC 2006 ATHENS /03/06 Troll A Platform NorwaySweden UK Troll A delivers gas to Kollsnes from all the field platforms 70km offshore 47% of Norway’s gas reserves 28% of Statoil’s total own production (oil and gas) Europe’s biggest offshore gas field in production providing 15% of Europe gas.

© ABB-EWEC 2006 ATHENS /03/06 Troll A Platform Total weight: tons Total height:472m Above water103m The largest man made structure moved across the surface of the earth as a complete unit Main objective with the pre- compression project was to increase the production capacity on Troll A

© ABB-EWEC 2006 ATHENS /03/06 Customer Values Reliable power supply Simple design incorporating redundancies Power quality control Operational Versatility Black Start Capability Remote onshore connections without the need for grid reinforcement Expandable modular systems that can easily be expanded to a multi-terminal system

© ABB-EWEC 2006 ATHENS /03/06 Customer Values Robust light-weight, oil-free cable system Simplified platform design Compact and low weight Reduced design weight to allow onshore assembly Short installation and implementation timescale Savings from reduction in Green House Gas Emissions

© ABB-EWEC 2006 ATHENS /03/06 Customer Values Savings from reduced need for offshore manning Remote operation Significantly lower maintenance Health Safety and Environmental impact Removal of risks associated with gas turbines Noise suppression from enclosed equipment

© ABB-EWEC 2006 ATHENS /03/06 Very High Voltage Motor 4-pole, 40MW Hz 56kV Troll A SM 70 km +/- 60kV HVDC Light 132kV Kollsnes ~ = = ~ Troll A HVDC Light ® – power from shore

© ABB-EWEC 2006 ATHENS /03/06 Troll A HVDC Light ® – power from shore Land based converter station at Kollsnes Modular converter unit on the Troll A platform Two HVDC Light ® transmissions units 2 x 40 MW nominal mechanical output ± 60 kV DC transmission voltage 70 km submarine cable

© ABB-EWEC 2006 ATHENS /03/06 Very High Voltage Motor for Compressors 56kV Very High Voltage Motors used to drive compressors Variable frequency operation for smooth start and operation Weight savings, no platform power transformer required Completely oil-free concept

© ABB-EWEC 2006 ATHENS /03/06 HVDC Light ® Submarine Cables 70km ABB sub sea cable Operating at +/-60kV DC Robust polymeric cables Lightweight design which simplifies installation Very long single lengths of cable loaded directly onto vessels from factory Oil free design significantly reduces environmental impact

© ABB-EWEC 2006 ATHENS /03/06 HVDC Light ® Onshore Converter Station Compact converter building Pre-assembled and tested equipment such as valves and control system helped to reduce delivery and installation timescales Fulfills high safety requirements for a gas plant installation

© ABB-EWEC 2006 ATHENS /03/06 Installation of HVDC Light ® Platform Module Installation commenced with auxiliary equipment on the first floor Second and third floor arrives in assembly area

© ABB-EWEC 2006 ATHENS /03/06 Installation of HVDC Light ® Platform Module Semiconductor valves suspended from the ceiling in order to withstand platform movement AC equipment installed on third level The module is then fully enclosed to maintain a weather proof controlled environment

© ABB-EWEC 2006 ATHENS /03/06 Offshore module ready for shipment!

© ABB-EWEC 2006 ATHENS /03/06 Installation of HVDC Light ® Platform Lift Completed module lifted gently into position by a large sea barge crane. The module is lowered onto a pre-fabricated platform extension unit The module is secured into its final position.

© ABB-EWEC 2006 ATHENS /03/06 Lessons Learned At Planning Stage High focus on finding an environmental appropriate solution Early selection of a suitable electrical solution (HVDC light technology) Sufficient time to study, mature and qualify the technical solution Building trust through open, and good cooperation.

© ABB-EWEC 2006 ATHENS /03/06 Lessons Learned At Execution Stage Continued open and good cooperation Common and joint approach to problem solving Ability and willingness to find win-win solutions on difficult technical, commercial and contractual challenges.

© ABB-EWEC 2006 ATHENS /03/06 Summary of Lessons Learnt Very high focus on Safety When introducing innovative solutions early and close involvement with the client to study and understand the new technical solutions is essential. Involve highly qualified personnel with high integrity, in problem solving Involve local knowledge and establish good relations with the relevant industry experts Statoil and ABB team pictured after successful commissioning of Troll A

© ABB-EWEC 2006 ATHENS /03/06 Offshore Power Supplies for Renewables ABB has a proven concept for power to and from shore High reliability, high voltage power supplies offshore are possible Greater understanding of technical risks Experience and lessons learnt are transferable to the offshore wind industry