An Opportunity for MgB2 Superconducting Magnetic Energy Storage

As the contribution of electricity generated from renewable sources (wind, wave, solar) grows, energy storage is widely regarded as the longer term solution for maintaining power quality and load levelling. Superconducting magnetic energy storage has been highlighted as one of many superconducting devices needed in a future clean-energy landscape, ensuring secure and continuous supply to consumers from a more distributed and intermittent supply base.Conventional conductors allow electric current to flow through them, although some energy is dissipated into heat as the current encounters a resistance. For temperatures below the critical temperature (Tc) a superconductor exhibits no measurable electrical resistance for DC currents. Furthermore much larger current densities can be carried than with normal Cu wire. The superconducting energy storage device is able to compactly store large energies in a compact volume with no storage losses.Superconducting magnetic energy storage devices are already in use for power quality in high-value manufacturing or experiments. The technology is however expensive as it uses 'LTS', low temperature superconductivity, which requires liquid helium at 4.2K to operate. The opportunity for this project comes from a new superconductor MgB2, discovered in 2001, which operates at higher temperatures. A higher operating temperature means a dry cooling system can be used which simplifies the design, reduces the size and hence the overall cost.The project assesses the suitability of MgB2 conductor for application in superconducting magnetic energy storage, (SMES) for future energy networks. The goal is to fabricate and test an MgB2 magnet coil and short length conductor to provide the necessary information for potential UK SMES manufacturers to assess both the conductor and magnet development. Due to the current facilities at the University of Southampton, a relatively small investment converts to a larger impact. Using the wide bore magnet facility an MgB2 coil can be tested in a large enough magnetic background field at temperatures between 10 and 20K, mitigating the cost of constructing a full size MgB2 magnet. Data from the coil measurement, together with tests on short length conductor will form the basis for the conductor and application assessment. Superconducting magnet manufacturers SIEMENS Magnet Technology and Oxford Instruments have expressed their interest in the project.

Impact from this proposal will be in 1) Knowledge 2) Quality of life 3) Health 4) Economy 1) The future energy grid is envisaged to meet our low-carbon energy requirements in 2030. Due to the massive scope of options such a re-construction can encompass, ranging from superconductor cables to smart grid intelligent energy usage, it is too early to decide the grid architecture; rather the technology must first be developed. Superconductors are one of five technologies thought to have the potential to meet the utility requirements in a low carbon future. The key to exploiting superconducting materials and enabling new significantly beneficial applications is a detailed understanding of the material physical properties. This project will characterize leading MgB2 materials and contribute to our understanding of MgB2 phenomena, improving the position and status of UK fundamental research in this area. Beneficiaries include industry and research communities involved in the development and manufacture of new superconducting devices and indirectly, suppliers of associated cryogenics. Amongst superconductor applications SMES is one of several, including cable, motor, generator, transformer, fly wheel, and fault current limiter, (FCL), all of which are already under development. Publication of the proposed research in leading applied superconductivity journals will have an impact broader than SMES application. How the properties of MgB2 conductors relate to conductor architecture is one of the key challenges facing superconductor applications and is relevant to all MgB2 superconductor applications. 2) The design of new power applications using superconductor materials (cables, motors, grid stability solutions) promises significant advances in energy efficiency. This translates as a dramatic reduction in waste and offers a potential contribution to UK international obligations on CO2 emissions. As the contribution of electricity generated from renewable sources (wind, wave, solar) grows, the risk of intermittent electricity supply and faults grows. SMES can help to mitigate problems in power quality so tomorrow's generation have the improved quality of life envisaged in a low carbon future. 3) The impact is not only for SMES but also for other superconductor magnet application.MgB2 is anticipated to replace LTS materials for MRI magnets. Basic research carried out in this proposal on the conductor, magnet construction, stability, and performance in medium magnetic fields above 4.2K is directly relevant to cryogen free MRI. A cryogen free MgB2 MRI magnet gives manufacturers the opportunity to substantially reduce unit cost, weight, energy consumption, and improve ease of use. New cheaper, lighter systems will undercut the current market, and expand it with more widespread usage. MRI has substantial impact on health, as more people have access to this technology, the impact becomes more widespread. 4) The economic impact is for MgB2 SMES and MRI. The UK has no current commitment to developing SMES systems, whilst other countries already have substantial commitment to either LTS or HTS systems. This project offers the opportunity to enter the market with a product that is forecast to be more competitive. The current market of about 3000 MRI systems sold annually shows little sign of significant further market growth, yet the commercial price of MRI is reducing annually. MgB2 offers the price reductions that will make the difference in a competitive market. With development work large corporations, (e.g. Siemens) will more likely put further inwards investment into the existing regional UK expertise in superconducting magnets and cryogenic systems.