Large scale exploitation of Renewable Energy Sources using the LH2-cooled MgB2 superconducting line

Among the long-term energy scenarios identified by major international organization in order to drastically reduce fossil fuels consumption and set out towards a sustainable energy system within the 21st century, the possibility of remote desert areas exploitation for large scale renewable energy production must be seriously considered. Desert areas are characterized by low cost wide lands with high levels of solar irradiation and wind availability. Interestingly, a little 0.3% of Sahara desert area assigned to solar systems would equal the total installed electrical power of Europe (700 GW). However, apart from generating costs (which should fall down with respect to conventional generation in future), two main technical problems would prevent this scenario. Firstly, fluctuations in the renewable power availability may lead to electric grid instability, reducing the quality of energy supply. Secondly, because deserts are typically far from high density populated and energy demanding areas, very high power lines would be necessary to transport the produced energy towards consumption regions. Hydrogen, produced by water electrolysis, is one of the most promising and studied means for storage and transmission of renewable energy, and is regarded as a possible future replacement of fossil fuels. When liquefied down to 20 K, hydrogen can be used for cooling an MgB2 superconducting line, allowing the design of a combined line for concurrent transport of electrical and chemical power. The feasibility study of a system for large scale energy storage and transport for connecting renewable energy plants sited in North Africa to the European electric grid is presented. The system is aimed at solving the problem of variable renewable energy availability using liquid hydrogen for energy storage. The superconducting MgB2 line could provide a very large power link between North Africa and Europe, through the Gibraltar’s strait, transporting both electrical energy and liquid hydrogen . The main aspects concerning the mechanical and electrical design of the system are examined. The electrical efficiency of the combined line is evaluated in comparison with HVDC conventional technology. The full system simulation during a reference day of solar availability is shown.