The transmission distance from Mezenskaya TPP to southern Germany is around 3,000 km. The transmission capacity for Stage 1 will be 20,000 MW and for Stage 2 a further 60,000 MW of capacity will be required. For these distances and capacities, dedicated point-to-point UHVDC systems will be required.
The length and capacity of the UHVDC lines is on the margins of existing technology. However lines in China and Brazil have been installed with comparable specifications. For example in China a 5,000 MW bi-pole UHVDC line transmits electricity over a distance of 1500 km between Yunnan and Guangdong at ±800 kV. A 2000 km line is also under construction to transmit 7,200 MW of power at the same voltage.
In Brazil the Rio Madeira hydroelectric projects will deliver over 6,000 MW of electricity to Sao Paulo, a distance of over 2500 km, using twin ±600 kV bipoles.
Multi-terminal HVDC technologies may be required for this project to enable the transmission lines to integrate with the grids of the countries through which they pass. Such technologies currently exist and are operational under the Quebec – New England HVDC multi terminal Transmission project and Italy–Corsica–Sardinia HVDC project. Another multi-terminal project which is currently under construction is the ±800 kV North-East Agra UHVDC link in India. This UHVDC link comprising of four terminals located at three converter stations will have a record 8,000 MW converter capacity, including a 2,000 MW redundancy, to transmit clean hydroelectric power from the North-Eastern and Eastern region of India to the city of Agra across a distance of 1,728 kilometres.
The technologies used in the above schemes may needs to be extended to achieve the 3,000 km distance required, with capacity of around 6,000 to 8,000 MW per ±800 kV or ±1000kV transmission line.
The route of the transmission lines for the proposed project has not yet been determined. Options exist for routes east and west of the Baltic Sea. Since several lines will be required, these can follow different routes to optimise the integration of the regional power systems.