Complementary Operation Optimization And Efficiency Evaluation Of Energy Power System With Carbon Capture

Under the background of global warming,China has responded positively to the international temperature control issue and put forward the "carbon neutrality" target to show its determination of low-carbon development.To achieve the "carbon neutrality"target in the energy power sector,on the one hand,it is necessary to increase carbon sinks through the introduction of carbon capture in the process of fossil energy use;on the other hand,it is necessary to reduce carbon emissions by increasing the proportion of clean renewable energy.In the current situation that thermal power still dominates in China,the introduction of carbon capture technology in thermal power to form carbon capture power plants is the main way to realize the "carbon sink" path in the energy power sector.In addition,as compared to traditional thermal power,the flexibility of carbon capture power plants will be greatly enhanced to strengthen the complementary capabilities of traditional thermal power and other components of the energy power system,especially when complemented with renewable energy generation,carbon capture power plants can mitigate the impact of high percentage of renewable energy penetration on the system by providing a wider range of regulation services.Therefore,introducing carbon capture can help achieve the "carbon neutrality" target in the energy power sector from both "carbon sink" directly and "carbon emission reduction" indirectly,and will enhance the safety and stability of the energy power system.The paper takes carbon capture power plants and the integrated multi-class complementary system as the research object,and focuses on the critical issues of complementary operation optimization and efficiency evaluation of energy power system containing carbon capture.The main research contents are as follows:(1)The supporting policies,practical experience and operation mechanism of carbon capture are summarized.Firstly,the supporting policies of carbon capture are overviewed;secondly,the current practice of introducing carbon capture into energy power system at home and abroad is sorted out,and the experience and inspiration of developing carbon capture are summarized with reference to the basic situation of China;finally,the mechanism of introducing carbon capture into energy power system from the perspective of energy flow,emission flow and cash flow is analyzed,which provides the policy basis and the theoretical and practical foundation for this paper.(2)A multi-dimensional cost analysis and technology selection for carbon capture is conducted.Firstly,the LCOE and MAC calculation models considering the technology learning effect are constructed;secondly,based on the carbon capture demand of coal and gas power under the "carbon neutrality" target.the development scenarios of various types of fossil energy carbon capture power plants are established;finally,the investment cost,power generation cost and emission reduction cost of various types of carbon capture power plants are compared with the development scenarios.The result shows that the post-combustion capture retrofit of stock SPC units and stock NGCC units can form carbon capture power plants with advantages in generation cost and emission reduction cost.(3)The operational optimization model of source-source complementary system with carbon capture is constructed.Firstly,in the background of renewable energy generation capacity declaration,a risk-neutral model is constructed to optimize the operation of the source-source complementary system with carbon capture;secondly,the risk-neutral model is transformed based on CVaR and RRCVaR by considering the antecedent decision-making properties of the power declaration and the risk-averse demand of decision makers;finally,different scenarios are set based on the presence or absence of risk-averse demand,carbon capture participation,and carbon emission constraints,and so on,to quantify the operation and benefits of the source-source complementary system under different scenarios.The results show that carbon capture power plant can increase the supply revenue of the source-source complementary system by effectively compensating the declared output deviation of renewable energy generating units;the CVaR model can effectively reduce the profit risk of the output declaration of the source-source complementary system,while the RRCVaR model can make the system decision with better risk aversion when the multiple probability distribution is not comparable.(4)The operational optimization model of source-load complementary system.with carbon capture is constructed.Firstly,a baseline price calculation model of time-of-use tariff by voltage level and customer type is developed,and a peak-valley period division method based on the remaining available generation capacity of the system is proposed;secondly,based on the background that the demand response mechanism changes the traditional "source-follow-load" dispatching mode,and based on the analysis of the profitability of each subject participating in demand response,a source-load complementary system operation optimization model is developed;finally,different scenarios are set up considering the presence or absence of demand response mechanism and carbon emission constraints to quantify the operation and benefits of the source-load complementary system under different scenarios.The result shows that carbon capture power plant and demand response mechanism can link up the consumption of renewable energy,which can guarantee and improve the benefit of each participant under the premise of improving the net benefit of source-load complementary system,among which,the generation side can reduce the cost of abandonment penalty,the grid side can save a lot of grid investment cost through peak-load reduction.and the customer side will reduce the transmission and distribution cost.(5)The operational optimization model of multi-energy complementary system with carbon capture is constructed.Firstly,the operation optimization model of m ulti-energy complementary system is constructed from two perspectives:independent and complementary.Secondly,based on the revenue enhancement and revenue distribution demands of multi-energy complementary operation,a multi-energy complementary system Nash negotiation model is constructed,and the model is decomposed into the maximization of complementary net revenue sub-problem and the transaction payment negotiation sub-problem.Finally,the system operation and revenue of independent energy supply and multi-energy complementary modes are measured separately,and the carbon capture efficiency and carbon price are used as sensitivity factors to analyse the system carbon emission and net revenue under the multi-energy complementary mode.The result shows that through the nearby consumption of renewable energy,gas-fired carbon capture power plant and carbon recycling of P2G,the external energy purchase of the multi-energy complementary system can be reduced,and the overall return of the system can be improved,and the implicit carbon sink can be obtained.Furthermore,the distributed and efficient solution of the model sub-problem can be achieved by using ADMM algorithm.(6)The complementary operation efficiency evaluation model of energy power system with carbon capture is constructed.Firstly,based on the principle of index selection,the evaluation index system of complementary operation efficiency of energy power system with carbon capture is constructed by considering the introduction of new necessary indexes such as carbon sink;secondly,a complementary operational efficiency evaluation model for energy power system containing carbon capture is constructed,which is divided into two parts,a horizontal evaluation model between different projects using DEA cross-efficiency and a vertical evaluation model between different cycles using Malmquist index;finally,using the optimization result data from the previous sections,the operational efficiency of the multi-class complementary system with carbon capture is evaluated and efficiency enhancement methods corresponding to different efficiency classifications are proposed.The result shows that:under the existing cost and price conditions,the operational efficiency of the source-source complementary projects with carbon capture participation are higher while the multi-energy complementary projects are lower,which is mainly related to the energy conversion efficiency of the equipment and capital investment;in addition,the introduction of carbon capture technology,carbon emission constraint and demand response mechanism can effectively improve the operational efficiency of the complementary systems.