Migrating towards renewable energy generation is driving the need for strengthening the distribution grid. HVDC cables are making the connections to bring power to you.
Indeed, reliable access to renewable energy relies on multiple generation sources that extend beyond the local level. HVDC cables make the connections between renewable energy sources and the grid that brings power to you.
Green energy from afar
Renewable energy skeptics and critics are quick to point out that without wind there is no wind power. Though this may be true on the local level, there is always wind power available elsewhere. The power grids just need to be strong enough and be properly interconnected to transport the energy from the source to the consumer destination. There’s no wind in the Baltic Sea? No problem. The wind farms in the North Sea, the solar power from Spain, or the hydroelectric plants in Norway come to the rescue. As long as there is green energy somewhere across the grid, reliable and constant access to renewable energy is a very viable option.
Riding the German corridor
Lately, huge steps in pushing the renewable power generation agenda forward have been taken in the form of the German Energiewende, where nuclear power plants in the south are being substituted with off-shore wind farms in the north. Big power generation projects are being realized. The latest step has been to plan and procure the energy highways transporting the energy from the north of Germany to the big population centers and industries of the south. The technology of choice is Extra High Voltage Direct Current cables. These so-called corridor cables extend hundreds of kilometers long.
The HVDC difference
What are these HVDC cables? How do they differ from HVAC cables from a manufacturing point of view? Almost all the same elements are found in an HVDC cable as in a familiar HVAC cable; aluminum or copper conductor, triple-layer insulation, metallic moisture barrier, and a plastic jacket for mechanical protection. The construction appears identical, yet there are significant differences. Manufacturing-wise, segmental conductors are not needed and different insulation material is used which requires different processing conditions. The insulation system with its three layers exhibits major differences compared to AC cables. Here, one strives to minimize the insulation conductivity, where the insulation material behaves differently during the manufacturing process. Those differences must be compensated for during process setup in order to achieve cable quality.
Made on our CV lines
Most corridor cables are insulated on our CV lines. This technology has been used to produce the vast majority of the HVDC cables existing today and will continue to do so in the future. Maillefer’s HV know-how and extrusion solutions are helping manufacturers find their way towards a reliable renewable energy future.
Markus Boström
Director, Technology
markus.bostrom@maillefer.net
