Method and application of carbon emission calculation for ultra-high voltage (UHV) project construction

Abstract

[Objective] As one of the seven key areas of“new infrastructure”development during China's 14th Five- Year Plan period, the ultra- high voltage (UHV) projects are the backbone of China's new power system and is of great significance to the transmission of clean energy. This study constructed a theoretical and methodological system suitable for the carbon emission measurement of UHV project construction in China, in order to clarify the carbon cost of project construction and assist project carbon management and the construction of new power systems under China's“dual carbon”goals. [Methods] Based on the life cycle assessment method, this study broke through the cost list- based measurement system and for the first time constructed the carbon source emission inventory system for UHV project construction from the perspective of carbon footprint. On this basis, a grouping calculation method for project construction carbon emissions was proposed, which enhances the applicability and accuracy of the method. The calculation and carbon emission reduction potential evaluation of the ± 800 kV UHVDC transmission project from Longdong to Shandong were conducted as an example. [Results] The results show that: (1) The method constructed in this article simplifies the calculation work to a certain extent, ensuring a relatively scientific and effective calculation of carbon emissions in the construction of ultra large transmission projects; (2) The overall carbon emissions in the construction phase are 3.367 × 106 tCO2e, with the main source of carbon emissions coming from non- traceable projects, accounting for 67.140% of the total; (3) The carbon emissions of unit investment are 1.667 tCO2e/10000 yuan, and the unit carbon emissions level of the large- scale super project in the power sector has not been improved. [Conclusion] The results verify the applicability of the carbon emission calculation method for UHV project construction formed in this study. The method provides a theoretical support for establishing carbon cost budgets for UHV projects in China, improving carbon emission management capabilities during the project construction phase, and assisting project carbon emission reductions. The study also revealed that fully utilizing the existing power grid foundation to plan project site selection and construction, innovating construction technology, introducing green materials, and application of digital technology in project construction management are highly promising paths of carbon emission reduction.