Nowadays, in the era of constantly growing appetite of energy and dwindling conventional resources for its generation, no one doubts that the idea of burning more coal to get more energy has to be revised and replaced by some more innovative solutions. Putting the problem of energy generation aside for a moment, it is also wise to think how to improve energy transport. Imagine how much could be saved if we were able to reduce the inevitable energy losses during the transport. We could save even more if we were able to eliminate them completely.One hundred percent efficiency of the energy transport? This may sound like a bit of science fiction, not far away from all these surreal ideas of a perpetuum-mobile. Every high-school student knows, that wires transporting electric current get hot and this heat is just the energy that we loose. However, lossless electric current transport through wires made of some specific materials has been an experimental fact known already for 100 years. The phenomenon of electric current flowing without any loss is known as superconductivity. Having such a wonderful tool at hand we should not worry about energy consumption so much. But why we still do? The main obstacle on the way to economically feasible applications of the conventional superconductors were extremely low temperatures that had to be maintained in order to keep superconductivity alive. The phenomenon simply disappears as soon as the temperature reaches the so-called critical value, and the wonderful lossless wires turn into usual resistive leads.
The breakthrough came in 1986 with the discovery of high temperature superconductors, however the word “high” still means temperatures well below -89.2 C, the world’s lowest temperature ever, recorded in Vostok polar station in Anatarctica. However, the critical temperature of high-temperature superconductors has hit the limit of -196 C for the first time, which is the boiling temperature of liquid nitrogen. Since then, the superconducting technology has left the era of the expensive liquid helium and entered the period of much more affordable liquid nitrogen has begun. With the price of liquid nitrogen being about 1/20 of that of liquid helium, this was a huge progress that opened the door to still not cheap, but already feasible applications.
There is a lot of players in the field of superconducting technology in the world. As for China’s position, they are not among the top ones when it comes to more high-tech applications, such as solid state implementations of quantum information processing, where superconductivity has been finding its place over the last few years. However, Chinese scientists and engineers are doing interesting things in the domain of material manufacturing and characterization, as well as more down-to-earth applications related to electric power transmission networks. There is a couple of small but dynamic, Beijing-based companies, that are doing well in integrating the technology. One of them, the Innopower Superconducting Cable Company, is led by US-educated scientist Dr. Xin Ying. When I met him a couple of years ago in the company’s headquarters in south Beijing’s Daxing Technology Development Zone, he was more than optimistic about prospects of the field, estimating the domestic demand for superconducting technology to reach the level of tens of billions RMB within the next twenty years. The young company, established in 2001 after Xin’s return from the United States, employs engineers and applied scientists, and about 30 percent of its employees hold a PhD . Their greatest success has been so far a fully operational 33.5-meter long section of a superconducting cable working in a power transformer station in Puji, Yunnan province. This project, completed in 2004, made China the third country, after the USA and Denmark, to successfully operate a high-temperature superconducting cable on the scale beyond experimental range. Now Innopower is working on a superconducting fault current limiter, which roughly speaking is a device that has to ensure the safety of a power transmission network in the case of a fault. With the USA, Germany, the UK, and Korea working extensively on the project, too, it is a demanding race and its outcome will be a test of creativity and innovativeness of Chinese superconducting industry.
With these ongoing projects, the overall funding for research and development in the field of high-temperature superconductivity is not as generous as it used to be just after the 1986 discovery. It may gain a new momentum though. This time motivated more by political than scientific reasons. A projection of the impact of the superconducting technology on the reduction of green-house emissions, made for the EU suggests that it is quite significant. The study estimates that by widespread utilization of high temperature superconductors in the EU, 31 TWh of electrical energy could be saved annually . This is 1.2% of the total generation, and in terms of greenhouse-gas emissions, it equals to 14.7 Mt of CO2 with average European value for emissions per kWh. This number is approximately 20 percent of the reduction in CO2-emissions from electricity generation required by the Kyoto Protocol. The next few years are going to show whether this path will be followed and what role will China play in the superconducting game.