Research On External Value Measurement And Incentive Mechanism Of Energy Storage In Microgrid

In recent years,as countries around the world have incorporated the development and effective utilization of renewable energy into the key research direction of their development strategy,and China’s relevant management measures and guiding policies on the development of new energy storage have been successively issued,renewable energy and energy storage related industries are developing rapidly.Microgrid,as a new management architecture closely focusing on the design purpose of the power demand of the whole power system and introducing the power supply concept of diversified power quality to users,can not only provide schedulable load for the local power system,but also meet the personalized needs of users.Energy storage system also plays an important role in many links of microgrid operation control,and has become an essential part of microgrid.However,the energy storage system has high investment cost and long investment payback period,and its self-financing ability is also poor;However,the economic benefits obtained by investors after investing in the energy storage system are poor,which leads to the low investment intention of investors;And the corresponding incentive mechanism has not been designed for the multiple stakeholders who benefit from energy storage.These adverse factors seriously restrict the development of China’s energy storage industry.Therefore,based on the externality theory and taking the energy storage system in the microgrid as the research object,this paper measures the externality value of the energy storage system.On this basis,the externality value is reasonably distributed between the energy storage operators and various stakeholders,and the externality value provided by the energy storage system to various multiple entities in the microgrid is fed back to the energy storage system providers in a certain distribution proportion,Based on this,an incentive mechanism which can effectively promote the healthy development of energy storage industry is designed to realize the subsidies and incentives for energy storage system providers.The main research contents of this paper include:(1)Analysis and measurement of externality value of energy storage system.Identify the internal value and external value of the energy storage system in the microgrid,and clarify the multiple stakeholders of the external value.Based on the externality theory,the externality value of energy storage system is analyzed and measured,that is,the benefits to other stakeholders in microgrid.(2)Research on external value distribution model of energy storage system.Based on the traditional Shapley value method,the external value generated by the energy storage system is reasonably distributed between the energy storage manufacturers and various stakeholders,and the distribution weight is modified based on the bargaining game,so as to identify the income value that these stakeholders should compensate to the energy storage providers.(3)Design of cost compensation incentive mechanism of energy storage system.In view of the external benefits brought by the energy storage system,based on the principal-agent theory,this paper puts forward the basic assumptions including the identification of the principal-agent relationship,the model and the cost compensation contract of the benefit energy storage system,and constructs the structure including the maximum expected benefits of the power regulatory authority(objective function)and the maximum expected benefits pursued by the stakeholders(incentive compatibility)Based on this,we can compare the principal-agent incentive model and the Agent Incentive Model under the condition that the principal-agent incentive mechanism is lower than the expected benefit,and analyze whether the principalagent incentive mechanism and the agent incentive mechanism can realize the basic benefit under the condition that the principal-agent incentive mechanism is lower than the expected benefit.The research conclusions based on the above research include:(1)The value of energy storage system in microgrid can be divided into internal value and external value.The internal value includes the arbitrage income brought by the charging and discharging operation of the energy storage system itself and the electricity income and capacity income brought by the participation of energy storage in auxiliary services.It is the actual economic income obtained by the energy storage operator.External value includes increasing the proportion of renewable energy power generation,effectively delaying and reducing the construction of power supply and power grid,reducing the loss of power failure of users,etc.For different stakeholders,their external value can be quantified respectively by increasing the on grid power or reducing the abandoned power and the corresponding electricity price,delaying the investment cost reduced by equipment upgrading,and reducing the power failure loss of important users.The results of example analysis show that the externality value of energy storage system to renewable energy generators is large,and the externality value to power users is small.(2)The example analysis results of the external value allocation model of energy storage system show that the weight allocation result of Shapley value method is that the energy storage manufacturer accounts for 50%,the other three stakeholders allocate the remaining 50%of the external value according to their own external value obtained by the energy storage manufacturer,and the multiple stakeholders should compensate half of their external value brought by the energy storage system to the energy storage manufacturer;The result of bargaining game mainly depends on the negotiation loss coefficient and negotiation order of all parties.In the first stage of game,energy storage manufacturers are in the position of putting forward the distribution scheme first,which has the first mover advantage.Although the revised distribution weight has decreased,it is still close to 50%.(3)As the principal,the power regulatory authority pursues the social benefits of the effective supply of energy storage system,and each interest subject pursues their own maximum economic benefits as the agent.In the situation of information asymmetry,with the improvement of the uncertainty of the external environment,the degree of risk aversion and the cost factor of effort,the incentive effect of regulators on stakeholders is weakening.Compared with the situation of asymmetric distribution of information,the greater the degree of risk aversion of power regulatory institutions,and the greater the degree of asymmetric distribution of information,which will lead to the greater risk aversion of power regulatory institutions.The results of example analysis show that the designed cost compensation incentive contract of energy storage system can enable all stakeholders to compensate the cost of energy storage manufacturers according to the result of value distribution corrected by bargaining game.