Alternative Pathway to Phase Down Coal Power and Achieve Negative Emission in China

Abstract

Although widely recognized as the key to climate goals, coal "phase down" has long been argued for its side effects on energy security and social development. Retrofitting coal power units with biomass and coal co-firing with a carbon capture and storage approach provides an alternative way to avoid these side effects and make deep carbon dioxide emission cuts or even achieve negative emission. However, there is a lack of clear answers to how much the maximum emission reduction potential this approach can unlock, which is the key information to promote this technology on a large scale. Here, we focus on helping China's 4536 coal power units make differentiated retrofit choices based on unit-level heterogeneity information and resource spatial matching results. We found that China's coal power units have the potential to achieve 0.4 Gt of negative CO 2 emission in 2025, and the cumulative negative CO 2 emission would reach 10.32 Gt by 2060. To achieve negative CO 2 emission, the biomass resource amount should be 1.65 times the existing agricultural and forestry residues, and the biomass and coal co-firing ratio should exceed 70%. Coal power units should grasp their time window; otherwise, the maximum negative potential would decrease at a rate of 0.35 Gt per year.

Spatially resolved land and grid model of carbon neutrality in China

“…In this study, we model carbon sinks exogenously in order to meet a certain negative emissions target ( 550 Mt/yr in the base case) adopted from an economy-wide decarbonization study ( 34 ), which used an integrated modeling approach to analyze China’s energy transition pathways to carbon neutrality. It projected that approximately 650 Mt CO 2 of negative emissions would need to be provided annually from BECCS by 2060 (considering positive emissions from partial capture fossil fuel CCS), which is in line with more detailed analyses on BECCS potential ( 53 , 54 ).…”

“…Given the availability of low-cost zero-carbon substitutes, the electricity sector is expected to reach neutrality earlier than other sectors. In addition, economy-wide studies show that it is cost-effective for several hard-to-abate economic activities with high marginal costs of abatement to be offset by negative emissions elsewhere, in particular power ( 34 , 53 , 54 ). In this study, we model carbon sinks exogenously in order to meet a certain negative emissions target ( 550 Mt/yr in the base case) adopted from an economy-wide decarbonization study ( 34 ), which used an integrated modeling approach to analyze China’s energy transition pathways to carbon neutrality.…”

Air Quality and Health Implications of Coal Power Retirements Attributed to Industrial Electricity Savings in China

“…The coal fleet contributes to about 6% of the national population-weighted PM 2.5 concentration in 2020, reaching 2.5 μg/m 3 (Figure S10). ,− The levels of PM 2.5 concentration in the coal-dominated power grids (i.e., North and East grids) are obviously higher than those in other regional grids. The top provinces in coal installation capacity are Shandong and Jiangsu, and they rank second (4.9 μg/m 3 ) and sixth (4.0 μg/m 3 ) respectively, in terms of contribution to PM 2.5 concentration from coal fleets (Figure S10).…”

Global biomethane and carbon dioxide removal potential through anaerobic digestion of waste biomass

“…In addition, waste biomass is a limited resource [20] and there is growing consensus that the social value of deploying biomass for CDR via BECCS may exceed its value for bioenergy production only [50][51][52]. Recent work has quantified BECCS potential in Europe, China, and the United States considering biomass feedstocks that do not create additional impacts on natural resources, namely crop residues, organic food waste, forestry residues, livestock manure, and wastewater [20,[53][54][55][56][57][58]. These studies focused on regional-scale analyses of BECCS potential and used different methods and sources of biomass feedstock, making results difficult to adopt in future climate mitigation policies.…”