Negligible carbon costs of UHVDC infrastructure delivering renewable electricity
Yijia Zhang, Ti Liu, Lin Yao, Qiujin Song, Chaochao Gao
Abstract
Ultra-high voltage direct current (UHVDC) transmission make it possible for efficient large-scale long-distance renewable energy deliver, while the infrastructure construction consumes significant amounts of material and energy. The carbon tradeoffs are often overlooked, however, hindering a holistic evaluation of its climate benefits. Here, by collecting field construction data from fifteen 500 kV transmission projects and applying the field data in a Life Cycle Assessment framework, we estimate the infrastructure-induced emissions of nine recently-constructed UHVDC projects in China to be 16.7 Mt CO 2 , which is negligible compare to an annual reduction of 305.2 Mt CO 2 these projects contribute by delivering renewable electricity at full load, multiplied by a 40-yr service lifetime. The tradeoff results may evolve with advancing energy storage technology at exporting region or CCUS application at importing region. Low-carbon strategies for UHVDC construction are therefore favored, especially under China's commitment to expanding UHVDC construction along the Belt and Road Initiative.