The geothermal energy supply is stable and it is less damaging to the environment than the use of fossil fuels or nuclear fuel.
According to the Epoch Times, geothermal energy can be underground (where temperatures are steady at 10-16 ° Celsius), hot water and rock deeper in the ground, or very deep melting magma beneath Earth's surface.The use of geothermal energy is quite diverse, such as using underground hot water to directly heat buildings, use water for human consumption, or pump water and hot steam to activate the turbine and create electricity.
National Geographic says geothermal power plants use three main methods to produce electricity: dry steam, flash steam, and binary cycles. New Zealand, Indonesia, the Philippines, the United States and Mexico now have commercial geothermal plants.
The dry-steam plant uses cracks in the ground, leading directly high-temperature steam (more than 235 degrees Celsius) through the pipe to the turbine of the generator. The power plant will absorb hot water under high pressure (over 182 degrees Celsius) and convert it to colder water with low pressure. This process creates steam that turns the turbine to generate electricity.
The binary cycle power plant uses hot water (geothermal) with an average temperature of 107 to 182 degrees Celsius. Hot water is led through the heat exchanger, evaporating the secondary liquid (low boiling point far more than water, such as isobutane or isopentane). Steam of secondary liquid used to run the generator. Binary systems are a relatively closed cycle, so there is almost no greenhouse gas emissions. Geothermal experts predict that this will be the main technical solution for geothermal power generation in the future.
Geothermal power supplies are more stable and less environmentally damaging than the use of fossil fuels or nuclear fuel. The environmental impact of geothermal energy use is negligible and is easily overcome if planning well.
Geothermal liquids can contain gas and heavy metals, but most geothermal power systems that humans use will return them underground. Harvest operations are also planned to avoid mixing geothermal liquids with groundwater, while removing adverse effects on nearby natural landscapes, such as hot springs. Some geothermal plants produce small amounts of CO2, but binary systems do not emit greenhouse gases at all.
Another controversial method is being tested to collect geothermal energy like "fracking" technology for oil and gas extraction. Water is pumped into the geothermal well, creating enough pressure to break the rock, releasing heat to produce hot water, steam and turning the turbine of the generator.
The scientists also considered the urban heat island effect as a source of geothermal energy. Urban areas are warmer than in rural areas (both above and below ground), due to the influence of buildings, basements, drainage and wastewater systems. Geothermal pumps in urban areas can provide heat for buildings in the winter and cool them in the summer.