With the increasing use of renewable energy (RE) sources located in remote or distant areas, long distance transmission systems are required to incorporate these alternative sources of energy into the existing power grid. This research paper presents a comparison between two transmission systems: high voltage alternating current (HVAC) and high voltage direct current (HVDC) transmission systems technology. Comparative analysis of the following transmission systems is conducted: the HVAC transmission system, the conventional HVDC with line-commutated convertors (LCC), and the HVDC with pulse-width modulation (PWM) - voltage source convertors (VSC). The economical, technical and environmental considerations of the HVAC and HVDC systems are analysed to determine the best-suited system to use in conjunction with a 1000 km transmission distance.