Pumped Storage Power Station Benefit Calculations And Economic Studies

The benefits (static and dynamic) and economic feasibility of the pumped storage power plant is being recognized all over the world. But in China,due to the unsuitability of organization of power industry to socialist market economy,there are many disagreed knowledge to pumped storage power plant so far. Therefore,it is very necessary to study calculating method of benefits of pumped storage power plant and analyze its economy for completing the regulation of power structure in the early new century.The benefits of pumped storage power plant can be divided into static benefits and dynamic benefits based on acknowledged classification. Static benefits are generated from peaking and valley-filling,which are further divided into capacity benefits and coal saving benefits. Dynamic benefits come from its fast starting and flexible operation,including frequency regulation,synchronous condenser operation,fast coverage of steep load gradient and synchronous spinning reserve.As for the calculation of static benefits of pumped storage plant,the alternative coefficient method is normally adopted at present. The adopted alternative coefficient for capacity is from 1.05 to 1.10 and for electric generation 1.05. In fact,the capacity benefits are related to maximum load,load curve and the weight of hydropower power capacity. While the benefits of coal consumption saving are related to load consumption characteristic and power structure in addition to maximum load and load curve of the power system. It is very evident that the method metioned above is too rough to use. In this paper,a new method is deeply studied on power and energy balance and fuelconsumption of power system relative to the static benefit. The overhaul of power units are arranged in terms of peaking capacity balance and the power loads are dispatched based on the principle of equal incremental coal consumption rate in the new method,which is anticipated to solve the economic operation of the power system. A computer program in Turbo-Basic is also compiled based on the new method in this paper.Pumped storage power plants work flexibly and start very fast. It can serve for synchronous spinning reserve,load following,frequency control and synchronous condenser operation. Due to the difficulty of quantitative calculation,the typical cases on dynamic function of pumped storage plant are qualitatively analyzed in this paper.As a peaking power plant,the gas turbines are usually taken as the alternatives of the pumped storage power plant for its economic evaluation. Nevertheless,the coal-fired thermal plants were adopted as the alternatives of the pumped-storage power plant due to the limitation of national policy in the past. With the progressive establishment of socialist market economy,oil-fired thermal plant should no longer be a limit for the each power system in China. In this paper,economic comparisons are conducted among pumped storage plant,coal-fired thermal plant and gas turbine and reasonable operation ranges are found for all power plants mentioned above.