Ready-to-implement low-carbon retrofit of coal-fired power plants in China: Optimal scenarios selection based on sludge and photovoltaic utilization

Yunchao Xia; Jian Deng; Bo Hu; Qing Yang; Jianlan Li; Hongqun Gu; Guiping Zhou

doi:10.1016/j.ese.2022.100147

Ready-to-implement low-carbon retrofit of coal-fired power plants in China: Optimal scenarios selection based on sludge and photovoltaic utilization

Environ Sci Ecotechnol. 2022 Feb 1:9:100147. doi: 10.1016/j.ese.2022.100147. eCollection 2022 Jan.

Authors

Yunchao Xia¹, Jian Deng², Bo Hu³, Qing Yang^{1

2

4}, Jianlan Li^{1

4}, Hongqun Gu³, Guiping Zhou³

Affiliations

¹ China-EU Institute for Clean and Renewable Energy, Huazhong University of Science & Technology, Wuhan, 430074, Hubei Province, China.
² State Key Laboratory of Coal Combustion, Huazhong University of Science & Technology, Wuhan, 430074, Hubei Province, China.
³ State Grid Liaoning Electric Power Co., Ltd, Shenyang, 110006, Liaoning Province, China.
⁴ School of Energy and Power Engineering, Huazhong University of Science & Technology, Wuhan, 430074, Hubei Province, China.

Abstract

Currently the flexible demand for high proportion penetration of renewable energy depends on coal-fired units (CFUs), and the large-scale phase-out of CFUs in a short time is not realistic in China. Due to urban expansion, approximately 458 Chinese coal-fired power plants (CFPPs) are now located in cities. Limited by space, urban CFUs face difficulty in becoming equipped with carbon capture and storage systems. This presents a sizeable challenge for the low-carbon transition of urban CFPPs and carbon neutral processes. Here, we present a ready-to-implement method to reduce the carbon emission of CFPPs in limited space: roof photovoltaic-assisted power generation combined with sludge co-combustion for coal-fired power generation systems (PVSCs). We also consider nonurban CFPPs with the method of roof photovoltaic-assisted power generation (PVs) only. Based on remaining life cycle analysis, we find that the PVSCs could save 28.47 Mt of coal, reduce CO₂ emissions by 69.76 Mt, treat 125.70 Mt of sludge, and also generate 12.08 billion RMB worth of electricity revenue per year. In addition, our scenario analysis shows that PVSCs are more profitable when choosing an urban CFU with a remaining life of more than 12 years and while the sludge treatment subsidy is set at 100 RMB t^-1. Under strict and lenient CFU decommissioning policies, CFUs with a remaining life of between 19 and 30 years and between 13 and 24 years should be selected for PVs, respectively. Thus, we conclude that PVSCs can not only generate economic benefits but also facilitate carbon reduction and solid waste treatment.

Keywords: CFPPs; Decarbonization; Optimal emission target selection; Roof photovoltaic; Sludge co-combustion.