Exploiting the Earth's geothermal energy

Geothermal sources provide stable energy and are less harmful to the environment than fossil or nuclear fuels.

According to Epoch Times, geothermal energy can be shallow in the ground (where the temperature is stable from 10-16 degrees Celsius), hot water and rocks deeper in the ground, or molten magma very deep beneath the surface. Earth face.

The use of geothermal energy is quite diverse, such as using underground hot water to directly heat buildings, greenhouses, drinking water, or pumping underground water and hot steam to turn turbines to generate electricity. .

National Geographic said that geothermal power plants apply three main methods to produce electricity: dry steam (dry steam) , steam pressure (flash steam) and binary cycle . New Zealand, Indonesia, the Philippines, the US and Mexico now all have commercial geothermal plants.

The dry steam plant uses fissures in the ground, directly leading high temperature steam (more than 235 degrees C) through the generator to the turbine of the generator. Pressure-suction steam power plant sucks deep hot water, high pressure (more than 182 degrees C) into cold water, low pressure. This process produces steam that turns the turbine to generate electricity.

Operation model of geothermal power plant.(Photo: AFEST).

Binary cycle power plants use geothermal hot water with average temperatures between 107 and 182 degrees Celsius. Hot water is channeled through a heat exchange system, evaporating secondary liquids with lower boiling temperatures than water. a lot (eg isobutane or isopentane). The steam of the secondary liquid is used to run the generator.The binary system is a relatively closed cycle so there is almost no greenhouse gas emission. Geothermal experts predict this will be the key technical solution for future geothermal power production.

Geothermal sources provide stable energy and are less harmful to the environment than fossil or nuclear fuels. The environmental impacts of using geothermal energy are negligible and easily overcome if well planned.

Geothermal liquids can contain gases and heavy metals, but most systems that exploit the geothermal energy people are using will bring them back to the surface. Mining activities are also arranged to avoid mixing geothermal liquids with groundwater, while eliminating harmful impacts to nearby natural landscapes, such as hot springs. Some geothermal plants produce small amounts of carbon dioxide, but the binary system does not emit greenhouse gases at all.

A controversial method is being tested to capture geothermal energy like "fracking" technology to help exploit oil and gas. Water is pumped to geothermal wells, creating enough pressure to break down rocks, releasing heat to produce hot water, steam to turn the turbine of a generator.

The scientists also looked at the urban heat island effect as a source of geothermal energy. Urban areas are warmer than rural areas both above and below the ground, due to the effects of tall buildings, basements, water and wastewater systems. Geothermal pumps in urban areas can provide heat to buildings in the winter and cool them in the summer.