HVDC Interconnectors Benefits and Challenges Electric Power Control Center Workshop Bled, Slovenia 18th May 2015 Ole Gjerde
Content of Presentation Background Experience Benefits Challenges Future
A Changing Power System
Experiencies with HVDC Interconnectors 1976 Skagerrak 1 (250 MW) 1977 Skagerrak 2 (250 MW) 1993 Skagerrak 3 (500 MW) 2008 NorNed (700 MW) 2014 Skagerrak 4 (700 MW) 2019 NordLink (1400 MW) 2021 NSN Link (1400 MW)
The Cable Laying Vessel C/S Skagerrak
3 key arguments for interconnectors Increased security of supply Prepares the move from fossil fuel consumption to renewable energy consumption
The NordLink project Linking Norway and Germany
The NSN Link Project Linking Norway and Great Britain
The Technology
Benefits of Interconnectors Congestion rent Producer surplus Consumer surplus Day ahead trade Capacity mechanism Trade of ancillary services
Example benefits Germany-Norway
Challenges in HVDC Interconnector projects Technical Commercial Environmental Regulatory
Technical Challenges - HVDC Interconnector Technical concept and solutions: Converters and converter stations Cable including submarine installations and protection Crossings Underground cable
Challenging Nature Steep Walls at Landfall for Cable
Challenging Weather Conditions
Challenges of Interconnectors Market integration results in harmonized market prices Results in change of flow on all interconnectors at the same time (same turn of the hour) Gives a ramping challenge for the operation
Challenges with new Interconnectors Future interconnector Interconnector capacity for South Norway increases from 2400 to 5200 MW For a full change of flow direction this means a change of up to 10400 MW Existing interconnector 3700 MW The change adds on to the morning and evening peak 1400 MW
Ramping Challenges Rate of change of flow on interconnectors: For the market; change from one hour to the next (Present Nordic limit: 600 MW/h) In operation (Present Nordic: 30MW/min, from 10 min before to 10 min after hour shift) Possible alternatives to manage ramping with new interconnectors: 1. Higher hourly ramp rate 2. Continuous ramping (use of the hour) 3. Optimize ramping constraints in the market coupling algorithm A solution will probably be a combination of alternatives
The new Cable Links - Effect on the grid in Norway Export mode Change in flow direction and volume
NSN Cable England - Norway
Challenges in Cable Submarine Installation Installation configuration Single cables in Norwegian and Danish waters Cable bundled in German sector
Example NordLink - Project Overview 1400 MW at +/- 515 kv DC VSC converter technology Grid connection points Tonstad (NO) Wilster (DE) Schleswig-Holstein Cable 514 km submarine cable route 55 km underground cable route in Germany 53km Overhead line in Norway Investment 1,5-2 billion
This is how we do it
Proposed European off-shore Supergrid Source: B. Andersen, Cigre SC B4, 2011
One conceptual plan of a super grid Linking renewable sources across North Africa, the Middle East and Europe. (Source: DESERTEC)
Thank You for Your Attention!