Research On The Choice Of Policy Tools Of Government Subsidy,Carbon-Reduction And Pricing For Promoting Microgrid Development

In recent years,microgrid has become an internationally recognized effective way to promote the large-scale development of renewable energy power generation by virtue of its advantages of high-power supply reliability,good power quality and making full use of renewable energy for power generation.However,at this stage,there have been many challenges in practical application that severely constraint the development of microgrid,such as high investment cost,lack of technical standards and imperfect laws and regulations system.The policy tools for microgrid development need to be improved urgently.Based on the internalization of external benefits generated by microgrid,this thesis takes the choice of policy tools for promoting microgrid development as research object.First of all,by offering in-depth analysis for the characteristics of microgrid,its externalities and policy mechanism,this paper introduces that the economic essence of microgrid policy function is to facilitate microgrid to acquire deserved internal profits from the external benefits generated by microgrid,such as social and environmental benefits,so as to offset a part of microgrid investment cost and promote microgrid development.The policy tools mainly include government subsidy policy tools,carbonreduction policy tools and power pricing policy tools.Next,taking the small electricity network composed of a vertically integrated electric utility investor and private investor as the modelling background,this paper proposes a choice model of subsidy policy tools for microgrid,which considers two subsidy tools,including conventional subsidy policy and energy storage subsidy,and uses the method combined evolutionary game with real options.Then,after the comprehensive evaluation of microgrid economic,social and environmental benefits,this paper respectively analyzes the costs and profits of government and power investor,who are the two main stakeholders for microgrid development.Considering the two carbon-reduction policy tools of carbon tax and carbon emission trading,this paper builds a choice model of carbon-reduction policy tools for microgrid by using the method of combining evolutionary game with real options.Finally,taking the multi-agent system in microgrid market,which comprises of government agent,local electric utility company agent,and multiple types of consumer agents,as the modelling background,this paper develops a choice model of power pricing policy tools between the electric utility company and different types of consumers,which considers two power pricing policy tools,including fixed pricing policy and seasonal pricing policy,and uses evolutionary game theory combined with real option theory.By using numerical simulation,the optimal choice of the three kinds of policy tools described above are analyzed.The results show that:(1)In terms of improving microgrid investment probability of various subsidy policy tools,conventional subsidy policy has more significant effect than energy storage subsidy policy.And the electricity price subsidy among them is shown to be better than that of initial cost subsidy.However,the electricity price subsidy’s combination with initial cost subsidy is recommended to both ensure investment value of microgrid and lower the investment threshold of microgrid.(2)Among the carbon-reduction policy tools,the effect of carbon tax policy is more significant than that of carbon emission trading policy for improving microgrid investment probability.But after comprehensively considering the overall effect of these two carbon-reduction tools for improving microgrid investment probability and increasing social welfare,the effect of carbon emission trading policy is better than carbon tax policy.And it will be more conductive to promote the development of microgrid.(3)Among the power pricing policy tools,the seasonal pricing policy can achieve smaller demand fluctuation and higher social welfare than the fixed pricing policy can do.The effect of seasonal pricing policy is better.However,the fixed pricing policy could effectively improve the profits of the electric utility company,which is much higher than the seasonal pricing policy do.Hence,the fixed pricing policy can be more suitable than seasonal pricing policy when the development of microgrid is under the initial development stage.The research results provide the corresponding analysis model to choose the subsidy policy tool,the carbon-reduction policy tool and the power pricing policy tool for promoting microgrid development.And also,the results provide the application means of various policy tools under different conditions,which have important theoretical and practical significance for guiding and supporting the development of microgrid with policy tools.