Abstract: Abstract: In this paper, Taking self-consumption of grid-connected photovoltaic power generation project in National Energy Group coal chemical enterprise as a case study, this paper calculates and and analyzes the power flow distribution and grid loss of the typical load representative day of 110kV substation of coal chemical enterprises before and after its self-consumption, combined with the goals of carbon peaking and carbon neutrality (dual carbon goals,hereafter), and the transition from dual control of energy consumption to dual control of carbon emission. The author investigated a large amount of data of coal chemical enterprises before and after photovoltaic grid-connection, including the electricity consumption, electricity price, substation operation mode, photovoltaic power generation, on-grid electricity price, pollutant emission reduction, standard coal saving. This paper also analyzes and compares the safety benefits, economic benefits, environmental benefits, and social benefits of photovoltaic before and after self-consumption from the National Energy Group enterprises, power grid enterprises, and society and shows the positive significance of PV self-consumption and near-subsumption and its development prospects, and achieve the deep integration of the coal chemical industry and PV industry by means of greening and differentiation, and provides power support for coal chemical enterprises to reduce costs and increase efficiency, and photovoltaic power generation enterprises to expand capacity and improve quality and healthy and high-quality development.This case sets a precedent of the first photovoltaic clean energy self-consumption and grid-connection in Bayannur area of Inner Mongolia, and provides the technical and managerial experience of grid-connection management for similar photovoltaic clean energy self-consumption with demonstration effect.