In order to quantitatively analyze the grid connected economy of PV project

the annual rate of power generation to grid（ARPGG） model was established

with the operation mode of "self-generating and self-supply in chief and remaining electricity for grid. Unit output

climatic conditions were deemed as the basis for typical daily unit output.Nearest neighbor clustering & grey interconnect degree methods were applied to form typical daily load curve. By means of dynamic comparison between unit output and the user load

the annual rate of generation to network is obtained. On this basis

an economic evaluation system in the whole life cycle of photovoltaic power generation project was framed. To testify its rationality and usability

a 50 MW grid-connected solar greenhouse was taken as the practical application case. The results shows that model bears better adaption to reality and the grid-connected photovoltaic power generation project is of good economic performance and worthwhile to invest.