Abstract: The ecological benefit is the main aim to achieve for implementing the project of small hydro-power for fuel. Based on the characteristics of the project, the authors present the grey forecast model for estimating annual electric power consumption needed in rural areas without the project on the basis of grey system theory. The electric power used in rural areas is divided into the electric power for livelihood and the conventional electric power, and the prediction model for conventional electric power was set up with the elastic coefficient method. The prediction model of grey theory and elastic coefficient method were verified to be valid for estimating electric power needed by rural and conventional electric power consumptions through applying the two models. The implementation of the project of small hydro-power for fuel does not only greatly increase the electric power for fuel, but also increase the conventional electric power consumption of the project area. The research laid a scientific foundation for evaluating environmental and ecological benefit, calculating the electric price and drafting the complementary program energy.