Research On Accommodating Curtailed Wind Power By CHP Installed Electric Boilers

In recent decades, with the rapid development of the world economy, the mass consumption of fossil fuels has caused severe environmental pollution and led to the sharp declines in their reserves. Therefore, many national governments are developing actively new renewable clean energy. As an excellent representative of clean energy, wind power has been developed rapidly. However in recent years, with the wind power penetration has been increasing continually, wind power curtailment is more and more serious in our country, especially at the nights of winter heating period in northern China.In order to solve the problem of wind power curtailment, combining with the characteristics of power system in our country, accommodating curtailed wind power by CHP installed electric boilers and its national economics are studied in the paper. Firstly, explain the reasons of wind power curtailment in northern China. Referring to the domestic and foreign existing research results and practical experience, analyze several feasible methods of solving the problem of wind power curtailment. Then, the method that CHP reduces its forced output power determined by heat to accommodate curtailed wind power via installed electric boilers is proposed. The essence of the method is using wind power instead of CHP units for power generation and heat supplying during the wind power curtailment period. Therefore, the method can reduce the coal consumption of the whole power system, and has obvious short-term coal-saving benefits. Secondly, taking the existence of investment cost into account, to evaluate the national economics of the method, the evaluation model whose core evaluation index is ENPV is established. The model has taken electric boiler installation capacity, wind power curtailment condition, coal price rising and other kinds of factors into consideration sufficiently. The model analysis results show that it is national economic feasible to implement the method as long as the actual average annual utilization hours of the installed electric boilers can reach the theoretical minimum of average annual utilization hours. Furthermore, give the method of calculating the optimal electric boiler installation capacity according to the wind power curtailment condition.Finally, based on the real data in the power grid of northern China, use the model to analyze the national economics of implementing the method. The analysis results of realistic examples show that it is national economic feasible to implement the method in every power grid of north China which has abundant curtailed wind power, but due to the different wind power curtailment conditions in every grid, the optimal installation capacity is perhaps different. In the severely curtailed wind power western Inner Mongolia gird, it has significant coal-saving effect and economic benefit to adopt the method of the paper. It is only a conservative estimate that EIRR can reach to a level of over20%.