Comparative analysis of systems for transporting renewable energy over long distances

This paper aims to determine the most efficient method for transporting energy from renewable sources to end users over distances from 1,000 to 7,000 km based on a comparative analysis of losses associated with transport. As energy carriers, electricity and hydrogen-containing substances, such as liquefied hydrogen, methylcyclogexane, ammonia and synthetic methane were compared. Losses occurring at each technological step of the energy transportation route using the energy carrier under analysis were summarized for further comparison. In addition, the qualitative characteristics of specific costs per unit and the environmental impact in the creation and operation of the respective energy transport facility were taken into account. The numerical values of the energy delivered to the consumer by the energy carriers under analysis were obtained. Electricity was established to be the most efficient energy carrier for a distance of 4,000-5,000 km; energy losses in this case achieved the value of 32% (excluding those on agreement of the load and electricity generation schedules). The use of methylcyclogexane for transporting renewable energy showed the greatest efficiency at a distance of over 5,000 km. It was shown that the total losses in transport of high-voltage electricity at a distance of 7,000 km comprise 37%. Transportation of electrical and thermal energy produced in cogeneration over a distance of 7,000 km involve the following total losses: methylcyclogexane - 33%, liquefied hydrogen - 47%, synthetic methane - 67% and synthetic ammonia - 70%. A comparison of systems for transporting renewable energy should consider such indicators as the minimum cost of energy for the end consumer and the minimum environmental impact. Future research will focus on a multi-criteria comparative assessment of various systems for renewable energy transport under real conditions.

renewables, energy efficiency of energy carrier transportation, hydrogen energy, direct current lines, methylcyclogexane, ammonia