Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Long-distance transport of green power: First successful testing of a 20 kA superconducting cable

11.03.2014

The growing deployment of renewable energy sources (RES) will have to be accompanied by a significant expansion of the electricity grids.

The places where the generation of energy from wind, solar or hydro would be most economically competitive are often located in remote areas (offshore wind for example), distant from the densely populated zones where the energy is needed.


The test station at CERN

In this perspective, the Institute for Advanced Sustainability Studies (IASS) together with CERN (European European Organization for Nuclear Research) reached an important milestone on February 20th with the successful testing of a prototype superconducting cable able to carry 20 kA of current.

Nobel Laureate and IASS Scientific Director Carlo Rubbia commented on this result: “This is really a breakthrough. For the first time, we have a real cable which offers a practical way of transporting large amounts electricity over long distances, using a simple configuration and cheap, widely available materials”.

The experiment, which was the first of its kind, took place in the laboratories of CERN in the framework of an IASS-CERN collaboration aimed at assessing the potential of electric power cables based on the superconducting material magnesium diboride (MgB2). The tested configuration consists of two very thin, 20 m-long MgB2 cables combined in series for direct current (DC) transmission, and placed inside a semi-flexible cryostat that uses helium gas to maintain the very low temperatures required to enable superconductivity.

During this latest test, the cable setup, which has a total diameter of only 16 cm, housed two MgB2 cables able to transfer a current of 20 kA at low temperatures of about 24 K, and showed very good and homogeneous superconducting properties.

In the future, this type of superconducting cable could be installed underground, with periodically spaced cryogenic stations; a technology that is similar to the widespread natural gas distribution grid. It would achieve capacities of 2 to 10 GW, or even higher, with operating voltages that can be tailored for optimised performance. To give an example, the planned German Suedlink transmission line, meant to connect the North Sea to Lower Fraconia, would have a capacity of 4 GW with a subsequent uprating to 12 GW by 2032 (Netzentwicklungsplan).

In comparison to the alternatives, these superconducting underground cables would provide several significant advantages ranging from efficiency, cost, ease of implementation and environmental impact. First of all, superconducting materials like MgB2 are able to transmit electrical power without incurring resistive losses, which on the contrary affect conventional HVDC (and AC) lines and increase with the length of the line. Fewer losses translate into increased economic profitability and better resource management, as less energy is wasted.

Another distinctive feature of MgB2 SC cables is their small size: the whole installation for a 4 GW 800 km-long bi-polar cable, including the cryogenic envelope, is expected to have a total diameter of about 30 cm, which is less than most existing natural gas pipelines and much smaller than the corridor width needed for standard HVDC underground cables (about 20 m for 10 GW in central Europe). These latter also suffer from heat dispersion issues that severely limit the maximum capacity and have negative consequences for soils; in the case of SC cables, this drawback is entirely eliminated.

Finally, the choice of underground cables instead of overhead lines carries the usual benefits: it enables underwater crossings and transmission within densely populated areas and avoids the need to build massive transmission towers. Public opposition to invasive and environmentally harmful overhead lines has become an important factor in the decision-making process regarding grid expansion projects. Therefore, the search for technological alternatives is paramount. Additionally, existing rights-of-way could be used to install SC cables.

The first cost estimates show that the investment costs for the construction of a 4 GW MgB2 transmission line would be up to several times lower than for a standard ±320 kV HVDC underground cable, and competitive with HVDC overhead lines. The relatively low cost of MgB2 SC cables stems from their low cost per kA and meter (due to inexpensive materials) and simple manufacturing process.

Presently, IASS and CERN are pioneering the development of MgB2 cables. The results of the recent test have confirmed the promising nature of magnesium diboride, especially with respect to alternative materials like the expensive high-temperature superconductors (HTS). Additional tests of the prototype cable are planned in the coming weeks with the purpose of conducting further measurements and experimenting under various conditions. In parallel to these experimental activities, IASS has established contacts with partners from European industries and transmission operators in order to undertake the next steps in the R&D process and move towards industrial application.

Weitere Informationen:

http://www.iass-potsdam.de
http://www.iass-potsdam.de/research-clusters/earth-energy-and-environment-e3/sci...

Corina Weber | idw - Informationsdienst Wissenschaft

Further reports about: CERN HVDC IASS Sustainability capacity construction diameter materials temperatures underground

More articles from Physics and Astronomy:

nachricht LIGO confirms RIT's breakthrough prediction of gravitational waves
12.02.2016 | Rochester Institute of Technology

nachricht Milestone in physics: gravitational waves detected with the laser system from LZH
12.02.2016 | Laser Zentrum Hannover e.V.

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Production of an AIDS vaccine in algae

Today, plants and microorganisms are heavily used for the production of medicinal products. The production of biopharmaceuticals in plants, also referred to as “Molecular Pharming”, represents a continuously growing field of plant biotechnology. Preferred host organisms include yeast and crop plants, such as maize and potato – plants with high demands. With the help of a special algal strain, the research team of Prof. Ralph Bock at the Max Planck Institute of Molecular Plant Physiology in Potsdam strives to develop a more efficient and resource-saving system for the production of medicines and vaccines. They tested its practicality by synthesizing a component of a potential AIDS vaccine.

The use of plants and microorganisms to produce pharmaceuticals is nothing new. In 1982, bacteria were genetically modified to produce human insulin, a drug...

Im Focus: The most accurate optical single-ion clock worldwide

Atomic clock experts from the Physikalisch-Technische Bundesanstalt (PTB) are the first research group in the world to have built an optical single-ion clock which attains an accuracy which had only been predicted theoretically so far. Their optical ytterbium clock achieved a relative systematic measurement uncertainty of 3 E-18. The results have been published in the current issue of the scientific journal "Physical Review Letters".

Atomic clock experts from the Physikalisch-Technische Bundesanstalt (PTB) are the first research group in the world to have built an optical single-ion clock...

Im Focus: Goodbye ground control: autonomous nanosatellites

The University of Würzburg has two new space projects in the pipeline which are concerned with the observation of planets and autonomous fault correction aboard satellites. The German Federal Ministry of Economic Affairs and Energy funds the projects with around 1.6 million euros.

Detecting tornadoes that sweep across Mars. Discovering meteors that fall to Earth. Investigating strange lightning that flashes from Earth's atmosphere into...

Im Focus: Flow phenomena on solid surfaces: Physicists highlight key role played by boundary layer velocity

Physicists from Saarland University and the ESPCI in Paris have shown how liquids on solid surfaces can be made to slide over the surface a bit like a bobsleigh on ice. The key is to apply a coating at the boundary between the liquid and the surface that induces the liquid to slip. This results in an increase in the average flow velocity of the liquid and its throughput. This was demonstrated by studying the behaviour of droplets on surfaces with different coatings as they evolved into the equilibrium state. The results could prove useful in optimizing industrial processes, such as the extrusion of plastics.

The study has been published in the respected academic journal PNAS (Proceedings of the National Academy of Sciences of the United States of America).

Im Focus: New study: How stable is the West Antarctic Ice Sheet?

Exceeding critical temperature limits in the Southern Ocean may cause the collapse of ice sheets and a sharp rise in sea levels

A future warming of the Southern Ocean caused by rising greenhouse gas concentrations in the atmosphere may severely disrupt the stability of the West...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Symposium on Climate Change Adaptation in Africa 2016

12.02.2016 | Event News

Travel grants available: Meet the world’s most proficient mathematicians and computer scientists

09.02.2016 | Event News

AKL’16: Experience Laser Technology Live in Europe´s Largest Laser Application Center!

02.02.2016 | Event News

 
Latest News

LIGO confirms RIT's breakthrough prediction of gravitational waves

12.02.2016 | Physics and Astronomy

Gene switch may repair DNA and prevent cancer

12.02.2016 | Life Sciences

Using 'Pacemakers' in spinal cord injuries

12.02.2016 | Medical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>