Energy demand forecast, based on various factors should change trend analysis in the study of domestic and foreign historical reality experience, broom and impact energy and possible future. Therefore the obtained data, especially in the energy demand of the long-term, itself is obtained under the assumption of certain conditions, such as the development of the national economy the possible speed, the improvement of production technology, the changes in the economic structure, the implementation of energy-saving measures and so on. These conditions may change at any time, so the prediction data shall also be adjusted accordingly, to make it more realistic. Although the numerical forecast is not plan index, but gives the development trend under certain conditions and range, but it is for the planning and policy, determine the research direction in the future is very
Important, can play a guidance and reference role, its change can also confirm the reason. If there is no prediction, will in the future to blindness, or take it one step at a time, it is difficult to make correct policy and planning.
Prediction method of energy demand, which is still in the exploration stage. "Here we will make a brief introduction of the commonly used method.
A match, the energy consumption elasticity coefficient method
Elasticity ratio of energy consumption is a quantity growth reflected energy consumption rate and economic growth rate proportional relationship between, the numerical value is the energy consumption of a certain period of the average annual growth rate of the national economy with the same period the average annual growth rate ratio, i.e.
Indicators of national economy, capitalist countries used GDP this comprehensive index; common industry total output value of China's total output value of agriculture, sometimes employment, or Hui income (social net output value) as the main indicators of national economy:
GNP = national income ten depreciation of fixed assets (according to the 5% National

Type of:
Q -- unit of GDP energy consumption;
Changes of Jin - a unit of GDP energy consumption rate
From (1 - 5 - 2) type can be seen"
When the oath = O, the unit GDP energy consumption has not changed, '= 1
It is said, energy consumption growth rate and the GDP growth rate are equal.
When the oath > O, 5p energy consumption per unit of GDP growing at eight > 1
It is said, energy consumption growth rate higher than the rate of growth of GNP.
When an 5p < o, energy consumption per unit of GDP is more and more low when eight < I.
It is said, energy consumption growth rate is less than the rate of growth of GNP.
Some factors affecting energy consumption, unit of GDP, the deviation from zero?
Energy consumption and GDP is a comprehensive index Pb"
"- side - zymA,
From (1 - 5 - 3) can be seen, the change in the structure of national economy, change the proportion of each department in the gross national product, national income changes directly affect the unit energy consumption. The development of the Department of energy consumption, high output, improve its national economy in the proportion, can reduce the effect of the unit GDP energy consumption.
The Department of energy consumption per unit output value is mainly related to the Department of energy efficiency, R is also affected by the product structure. Through the strengthening of management, technical measures, update the old equipment. The new process and new equipment, energy saving, as well as the development of high output, low energy consumption of high-end products, energy consumption per unit output value of all departments to reduce the effect.

See from the above analysis of the elastic coefficient of energy consumption can be ', to seek the future energy consumption elasticity coefficient for a period of more accurate values, will be calculated according to the future departments share in GDP energy consumption per unit output value proportion and each department. And, in the prediction of the elastic coefficient of energy consumption, demand often have been calculated energy, thus losing elasticity ratio of energy consumption. If the method used is simple compared to determine the elastic coefficient of a future period, it is difficult to quantitatively describe the problem. In addition, the numerical range of the energy consumption elasticity coefficient is very wide, can change between the positive, negative infinity, when the energy consumption of an average annual growth rate of the national economy and the average annual growth rate is negative, the coefficient of elasticity of energy consumption will be chaos.