According to preliminary estimation, there are 2.62 billion m3 of underground water can be exploited every year in Beijing .If all of these are used in heating with pump, the energy collected amounts to 22% of the heat produced by 12 million tons of coal in Beijing in 2004 (see chart4). However, low grade energy collected from shallow soil and rock underground in Beijing corresponds to 333 times of heating energy in Beijing which is far more than the energy can be collected from underground water. Therefore, there will be limits in collecting shallow geothermal energy by pumping underground water.
Shallow geothermal energy is different from traditional energy. Different from traditional energy resource, shallow geothermal energy is regenerative and recycled. It is of little possibilities to exhaust the shallow geothermal energy if only solar energy and heat energy of the earth’s core.
Indicated from chart 4, regenerated shallow geothermal energy nationwide every year equals to 1178 times of heat produced by 1.97 tons of coal nationwide in 2004 and 13636 times of 440 million KW produced by the generator in the whole country. And the grade is far higher than the energy consumed at the present stage in China and capacity of the electricity generator, which values great in collecting and utilizing. There are great possibilities to utilize the shallow geothermal energy as the first choice alternative source combined with mature building heating/ cooling technologies.
