A concept for dual gaseous and electric energy transmission

Abstract

The trend towards decentralization of electricity production, the rising share of stochastic generators and more stringent consumer needs govern the planning of future networks. A widely discussed concept is that of integrated planning of chemical and electrical power systems. The vision of future energy networks project goes one step further and proposes a common infrastructure for both gas and electricity. A combined transmission device (a so-called interconnector), consisting of a hollow electrical conductor with internal gas flow, will offer several benefits such as simpler overall planning, synergetic effects and new opportunities like inline storage of chemical energy. The gas flow can be used for the cooling of the electrical conductor. The extracted heat can be reused at the terminals. In a first step, a generic model for a device with non-isothermal compressible gas flow and electricity transmission has been developed to investigate the operation characteristics and limitations of the interconnector. A particular issue is the coupling between the transmitted electrical and chemical power, as the gas flow also serves to cool down the electrical conductor. Physical and construction aspects limit the possible operation range of chemical versus electrical power. This work presents the methodology used to determine these limitations and their implications on the operation of the interconnector. The principle of combined energy transmission can be extended to liquid chemical energy, district heating and further energy carriers.