Long-term transition of China's power sector under carbon neutrality target and water withdrawal constraint

Deep carbon mitigation and water resources conservation are two interacted environmental challenges that China's power sector is facing. We investigate long-term transition pathways (2020-2050) of China's power sector under carbon neutrality target and water withdrawal constraint using an integrated capacity expansion and dispatch model: SWITCH-China. We find that achieving carbon neutrality before 2060 under moderate cost decline of renewables by 10-20% depends heavily on large scale deployment of coal-fired power generation with carbon capture and storage (CCS) since 2035 in China's water-deficient northwestern regions, which may incur significant water penalties in arid catchments. Introducing water withdrawal constraints at the secondary river basin level can reduce the reliance on coal-CCS power generation to achieve carbon neutrality, promote the application of air-cooling technology, and reallocate newly built coal power capacities from northwestern regions to northeastern and southern regions. If levelized cost of renewables can decline rapidly by about 70%, demand for coal power generation with CCS will be significantly reduced by more than 80% and solar photovoltaic (PV) and wind could account for about 70% of the national total power generation by 2050. The transition pathway under low-cost renewables also creates water conservation co-benefits of around 10 billion m(3) annually compared to the reference scenario.

Automated summary

Given the dual challenges of deep carbon mitigation and water resources conservation in China's power sector, the transition pathway towards carbon neutrality by 2050 will require a shift towards low-cost renewables, reduced reliance on coal-CCS power generation, and strategic reallocation of power capacities. Rapid cost declines in renewables could lead to significant reductions in coal power generation with CCS and greater integration of solar photovoltaic and wind energy, with potential co-benefits of water conservation.