Superconductors unlocking energy saving potential

15th June 2007 By: Karel Smrcka

Energy efficiency and the reduction of carbon dioxide emissions have been headline news in recent weeks and months.These issues also have a decisive impact on the electricity industry. International power trading and the integration of regenerative  energy sources place considerable pressure on distribution networks.

This pressure will increase in line with the rapid growth in cross-border electricity transmission. Superconducting components play a key role in maintaining the reliability of power supplies, and superconducting was one of the key issues at the Hanover Industry Fair 2007.

The discovery of superconducting dates back to 1911. A second boom occurred in the spring of 1987, when physicists at IBM’s Swiss research labo- ratory discovered that copper oxide compounds displayed superconducting properties at temperatures in excess of  –180 730C. The previous limit had been well below –200 730C. This marked the birth of high-temperature superconducting.

However, only today is it possible to exploit the full potential of this technology. Only now are materials available that can be produced cheaply and in large quantities. This is a precondition for large-scale industrial applications. The spectrum ranges from fast computer chips to high-performance electric motors and efficient power-distribution networks.

Numerous practical applications are in the pipeline. For example, superconducting current limiters could ensure the stable operation of high-voltage networks. They are well on the way to market readiness. The function of such current limiters is to curb the destructive effects of short circuits. Installed in the node points of high-voltage networks, they provide the basis for creating more closely meshed redundant structures. Further, they reduce costs when adapting power networks to future requirements.

Superconducting systems deliver percep- tible benefits all along the energy supply chain. In particular, they minimise transmission losses during power generation and distribution. The electrons in a superconductor move practically without any resistance and, hence, enable power densities that are about 100 times higher than in a conventional copper cable. This, in turn, provides the basis for creating more efficient and/or more compact components.

In countries such as the US and Japan, super- conducting has long since ceased to be a purely experimental discipline. The US Department of Energy, for instance, has earmarked some $25-million yearly for energy-related superconducting applications. The US Department of Defense is spending a similar amount on the development of compact superconducting marine propulsion units.

The situation is similar in Japan and Korea, where more than $100-million of public funds has been set aside for superconducting energy technology up to 2010 within the framework of the ‘Twenty-first Century Frontier R&D’ programme.

According to industry experts, the international superconducting market will increase to more than €2-billion by 2010. This figure is expected to rise to nearly €50-billion by 2020.