Electricity for heating and storage: geothermal energy development

The research on deep geothermal energy storage in China started late, and the current research on deep aquifer underground heat storage undertaken by the geothermal team of the Chinese Academy of Sciences has entered the stage of technology research and development and demonstration project construction from theoretical model research.

As a huge natural energy storage, geothermal storage is most suitable for the function of energy storage and stable thermal energy output in a multi-energy complementary system. It can save renewable energy such as wind energy and solar energy, realize efficient large-scale cross-season energy storage utilization, improve the utilization efficiency of renewable energy and overcome the shortcomings of intermittenity and instability of renewable energy. It can accelerate the adjustment of China's energy structure and help achieve the development goals of "carbon peak" and "carbon neutrality".

According to the study, a survey of 74 shallow geothermal energy storage systems in the Netherlands shows that for every 1m3 of groundwater extracted from the system, an average CO2 reduction of 0.46kg can be achieved. For a small-scale geothermal energy storage system (0.1-3MW), this is equivalent to reducing CO2 emissions by 150t/a per year, and for a large-scale system (5-30MW), carbon emissions can be reduced by up to 1500t/a per year. In contrast, the average CO2 reduction for ground source heat pump (GSHP) systems is between 1.8 and 4.0t/a.

The world's largest shallow geothermal energy storage system on the campus of the University of Technology in Eindhoven (Netherlands) can reportedly reduce emissions by more than 13,000 tons of CO2 per year, which is equivalent to the average annual carbon emissions of 800 US citizens or 1,300 German citizens.

At the same time, under certain conditions, the geothermal energy storage system has a more significant economic benefit advantage than the ordinary geothermal system. The return on investment time of a typical geothermal energy storage system is only 2 to 10a. Geothermal energy storage systems for refrigeration have an even shorter return on investment because the stored cold capacity can be used directly, without the need for a heat pump. According to research reports。