HTS-powercables.nl B.V. 1 Future long distance electricity transmission using HTS HVDC cables O. A. Chevtchenko, R. Bakker and J. J. Smit * HTS-powercables.nl B.V., Koperweg 45, 7335 DS Apeldoorn, The Netherlands Corresponding author: O. A. Chevtchenko, info@hts-powercables.nl * J. J. Smit can be contacted at: j.j.smit@outlook.com Publication date: 17 November 2015 (in the final form: 25 November 2015) Abstract In this paper a need is identified for 250-2000 km-long transmission links with capacity of 10-75 GW for the future high voltage direct current (HVDC) overlay grid connecting e.g., EUMENA countries, for which the costs of 500 B€ are foreseen. Transmission options available for such links are carefully selected and compared. A concept of high temperature superconducting (HTS) HVDC cable cooled with liquid nitrogen (LN 2 ) is proposed that addresses the identified challenges. The proposed cable concept is described and main specifications of such cable are derived. In conclusion, we expect that proposed HTS HVDC cable in many cases will be superior to conventional overhead line, elpipe or MgB 2 superconducting cable cooled with liquid hydrogen (LH 2 ). 1. Introduction A comparison of alternatives to deliver electricity from the energy source (coal in this case) to the customer at 1- 5 GW over 1000 km distance indicates that a high voltage direct current (HVDC) link using overhead line (OHL) is the most appropriate economically and environmentally, further reading is available [1-2]. Meanwhile a question arises how this statement applies to the power range of 10 to 75 GW and assuming other remote energy sources: such as hydro-, wind and solar. For example, from fig. 1 it is clear that for the future overlay HVDC grid the links (many up to 1000 km-long) will be required with capacities between 10 and 75 GW. Long HVDC links using OHL exist up to 6.4 GW and under consideration between 10 and 30 GW. On the other hand, conventional cables are limited in capacity by 1-3 GW and are 5-6 times more expensive than OHL ([2.1], Table 1 therein). Underground el-pipes are designed for capacities up to 24 GW [3], but they are more expensive as it is clear from Table 1 below. Therefore as it follows from Fig. 1 in a “business as usual” scenario, Europe one day will be covered (at the cost of 500 B€ [2]) by an additional grid of HVDC OHLs. To give an idea, a tower of a 6.4 GW bipole OHL is physically 50 m tall and 20 m wide (requiring a corridor at 100% annoyance level of 50 m tall and 300 m wide for a single 20 GW bipole). Figure 1. Expected HVDC overlay grid (with the line capacities) by year 2050 in EUMENA countries, according to [2] (the renewable energy sources are indicated, see fig. 5 in [2] for details) Hydro: 200 GW Wind: 300 GW Solar: 700 GW 1000 km: ⏐----------------⏐