Geothermal energy is a kind of renewable energy
The earth is a huge thermal pool with enormous heat.
Through volcanic eruptions, thermal conduction in rock formations, hot springs, and movements of heat-carrying groundwater, the source of thermal energy is continuously sent to the surface, called geothermal energy.
Geothermal resources refer to the thermal energy and its associated useful components in the geothermal fluids and the geothermal fluids that can be scientifically and reasonably developed under the current technical and geological environment. It is part of the mineral resources. A highly clean renewable energy source.
The traditional fossil energy pollution of the environment is very serious. Countries around the world have been researching and developing new energy sources, especially renewable energy, to gradually reduce the consumption of traditional energy. Geothermal energy, due to its huge storage capacity and low negative impact on the environment, is called clean energy. It plays an important role in relieving energy supply pressure and improving the ecological environment. It is listed as one of the new energy sources for research and development by countries all over the world.
Classifications of Geothermal energy
High temperature geothermal energy
It exists in the form of steam and is usually related to its location.
This type of geothermal energy is the natural heat extracted from the earth’s crust. This energy comes from the lava inside the earth and exists in the form of heat.
Shallow surface geothermal energy
It exists in the form of warm water, warm-hot water and hot water. Through the flow of groundwater and lava flowing to the crust 1 to 5 km from the ground, the heat can be transferred to a place closer to the ground.
High-temperature lava heats nearby groundwater, which eventually oozes out of the ground.
The easiest and most cost-effective way to apply geothermal energy is to use these heat sources directly and extract their energy.
The shallow geothermal energy is not limited by the region, the resources are abundant, the distribution temperature is stable, and the development technology is relatively mature, such as the ground source heat pump which is widely used at present.
Features of geothermal energy
- Different from hydropower, wind energy, solar energy, etc., the use of geothermal energy is not limited by daylight and seasonal changes. Generally, it does not need to be equipped with energy storage links, and the operation is stable. High-temperature hot water or steam coming out of geothermal energy wells can directly drive the steam turbine. Calculated from the amount of heat and electricity used, 72% of the time. Geothermal energy can be utilized. Compared to the time utilization of geothermal energy, hydropower generation is 42%, wind energy is 21%, and solar energy is only 14%.
- Compared with the CO2 and sulfur oxide emissions generated by coal, fuel and natural gas energy generation, geothermal power generation carbon emissions are an order of magnitude lower than the former.
- Geothermal energy has a small maintenance workload and long service life of hardware equipment after the initial equipment is built.
Current status of geothermal energy utilization
Geothermal power generation
The cost of geothermal power generation is lower than that of hydropower, thermal power and nuclear power in most cases. The utilization time of equipment is long. The investment in construction is generally lower than that of hydropower stations, and it is not affected by rainfall and seasonal changes. Power generation is stable and can greatly reduce environmental pollution.
For areas with high temperature geothermal resources, geothermal power generation is the preferred method for geothermal utilization.
At present, geothermal power stations use mainly natural steam and hot water underground.
Ireland has been using geothermal power for a total of 170 megawatts of geothermal installed capacity, accounting for 13.04% of the country’s total installed capacity.
Australia A 20 kW pilot geothermal power plant was built in 1986 in South Australia, and a 150 kW power plant was built in Bowesville and Queensland from 1991 to 1992. In recent years, Australia has attached great importance to the development of “hot rocks” for power generation, which is expected to be the main provider of energy for the country in the next decade.
At present, most of the geothermal power stations in operation worldwide are high-temperature power stations, and medium- and low-temperature power generation has also been rapidly developed.
On June 14, 2011, the Geothermal Energy Report released by the International Energy Agency (IEA) stated that geothermal energy and power generation have at least a tenfold increase in potential from now to 2050.
The initial investment in geothermal heating is relatively high, but the operating cost is only one-fourth of that of oil-fired boilers. It is non-polluting and can be used for hot water supply day and night.
It also saves energy, transportation and land occupation, etc.
It has obvious economic and social benefits and is an ideal heating energy source.
Iceland, located in the alpine region, is the country with the best development and utilization of geothermal heating. The country built the world’s first geothermal heating system in Reykjavik in 1928. Today, this heating system has developed perfect, 7740 tons of 80 °C hot water can be extracted from the underground for 110,000 residents each hour.
Now the Icelandic capital has been hailed as “the cleanest smoke-free city in the world” without towering chimneys.
Geothermal energy for industry and agriculture
The application of geothermal energy in agriculture is very broad.
For example, using suitable geothermal water to irrigate farmland can promote early maturity and increase yield;
Using geothermal water to raise fish, at 28 ° C water temperature can accelerate fish fattening and improve fish yield;
Use geothermal to build greenhouses, raise vegetables, grow vegetables and raise flowers, especially for the northern areas, it will help to save conventional energy, ensure the supply of winter vegetables in cold regions.
Use geothermal heat to warm the biogas tank to increase biogas production.
Direct use of geothermal energy in agriculture is a cost-effective way.
In addition to heating for agriculture, geothermal energy can also be used for industrial plant, like dry grains and processed foods, as a heat source for wood, paper, leather, textile, wine, sugar and other production processes.
Geothermal heat for health care
Geothermal water is extracted from the deep underground to the ground and often contains some special chemical elements, which makes it have a certain medical effect.
For example, carbonated mineral water can regulate gastric acid and balance the body’s pH;
Iron-bearing mineral water can treat iron deficiency anemia;
Hydrogen spring, sulfur water and hydrogen bath can treat neurasthenia, skin diseases and arthritis.
The advantages of geothermal energy are obvious, and more and more countries and regions have recognized this and paid enough attention.
The development and utilization of geothermal energy as a resource has become increasingly widespread, which has facilitated people’s lives, promoted the development of society, and promoted the progress of the times.
However, the research on geothermal energy is not yet mature, and there are many defects in the development and utilization of geothermal resources.
How to scientifically, efficiently and fully utilize geothermal energy as a resource for development and utilization has a profound research significance.