What is Geothermal Energy?

Geothermal Energy is the natural thermal energy extracted from the earth's crust. This energy comes from lava inside the earth and exists in the form of heat. It is the energy that causes volcanic eruptions and earthquakes. ^[1]

Humans have long used geothermal energy, such as bathing in hot springs, medical treatment, using underground hot water for heating, building crop greenhouses, aquaculture and drying

Geothermal power is actually the underground

The total heat content of rocks and liquids at a depth of 5,000 meters above the earth's surface and above 15 ° C is estimated to be about 14.5 × 10 ^ 25 joules (J), which is equivalent to about 4948 trillion tons (t)

Geothermal energy is concentrated on the edge of the tectonic plate, and this area is also

The use of geothermal energy can be divided into two categories: geothermal power generation and direct utilization.

According to China's geothermal development and utilization status, resource potential assessment and national and regional economic development forecasts, the geothermal industry planning goals, initial tasks, mid-term, and long-term phases ^[6]

In the application of various renewable energy sources, geothermal energy appears to be relatively low-key. People pay more attention to the amount of solar energy from space, but ignore the rich resources given to human beings by the earth itself. Geothermal energy may become an important part of future energy. .

Relative to solar and

(1) The temperature and pressure of geothermal steam are not as high as thermal power generation, so the utilization rate of geothermal is low. The thermal efficiency of old generators like Geises is only 14.3%, so that the amount of cooling water is more than that of ordinary power stations

China's use of geothermal power has just begun. Some places have only used underground hot water to build small power stations, which has been a success. This is a good start for geothermal applications. China has found that the geothermal temperature is relatively low and the taste is poor. It should be more suitable for heating and heating. Taking Beijing's geothermal field as an example, it belongs to the category of low-temperature hot water, buried deep between 400-2500m, and the temperature is in the range of 38-70 ° C. According to a rough estimate, it can be used for dyeing and weaving, air conditioning, fish farming, heating, medical treatment, bathing, etc., and the effect is good, which can save 4,300 tons of coal each year.

Examples of the actual environmental value of geothermal applications:

(1) Reykjivak (located in

Tianjin Municipal Government and Ministry of Land and Resources jointly hold Tianjin

If you dig 6 feet underground, you will find that the underground temperature in any part of the United States remains between 45 and 75 degrees Fahrenheit. This provides unique conditions for the use of geothermal energy. Heating a home with a heat pump is a typical use of geothermal energy. Despite its high cost, its many advantages such as simplicity, reliability, noiselessness, and low pollution have allowed more and more attention to geothermal pumps.

Unlike its popularity in Europe, geothermal pumps have not really been promoted in the United States, at least so far. In fact, the geothermal resource reserves in the United States are surprisingly large, and the utilization rate is less than 1%. Americans don't seem to be too cold about this type of home heating. However, with the continuous expansion of the geothermal pump market in the United States, great progress has been made in supply, sales and service, and a market network has been formed. At the same time, geothermal pump dealers are also beginning to realize that they want to make this new thing acceptable to Americans who have not had much contact with geothermal energy in the past, and must vigorously promote its advantages.

Objectively speaking, although the United States has abundant geothermal resources, geothermal pumps are not a very versatile home heating method. Although geothermal pumps can work well in most areas, using geothermal pumps is a bit more cumbersome than conventional heating methods. In addition to knowing what type of system is suitable, you need to know the installation cost and energy consumption cost, and the installation of the geothermal pump is relatively complicated, which has made many users who are interested in it retreat ^[1] .

Geothermal pump advantages

So why choose a geothermal pump for a family?

Geothermal pump

First, the most attractive aspect of geothermal pump heating is its high efficiency. This means that electricity can be saved, which can effectively reduce electricity bills.

Ever since geothermal began to be used in the United States in the 1940s, geothermal pump technology has continued to evolve. Compared to using air conditioners for heating or cooling, geothermal heat pumps are significantly more efficient, and more reliable and durable. The life of a geothermal pump can be as long as 25 to 50 years.

In addition to high efficiency and long-term use, geothermal heat pumps also have advantages such as low noise and low maintenance costs. It's a good deal no matter how you look at it. In Oklahoma, a house with an area of about 280 square meters uses a geothermal pump and only needs $ 60 per month to meet all of its energy needs ^[3] .

However, due to the many factors that need to be considered in the use of geothermal pumps, including local geological conditions and other uncertain factors, the promotion of geothermal pumps still faces many obstacles. Geothermal power stations, but the development of geothermal utilization is still slow and difficult. Because if you want to build a large power generation facility, you have to go deep into the ground. Many times a project needs to get tens of thousands of dollars for pre-exploration. On average, every mile drilled requires dozens of diamond drill bits, and a drill bit costs at least $ 2,000. But after drilling deep underground, there may not be enough reserves. Therefore, the development of underground thermal energy also comes at a price. In addition, the cost of installing a geothermal pump is difficult to estimate. Due to different geographical conditions, it is difficult to calculate the cost of a representative geothermal pump.

However, these failed to hinder the government's determination to promote the development of the geothermal industry. In addition to home heating and cooling systems, geothermal power generation is also an important way to use geothermal energy. According to statistics released by the American Geothermal Energy Association in 2010, geothermal power generation has brought the total installed capacity of the United States to 3.15 GW, making the United States the world's largest producer of geothermal power. In 2011, the United States geothermal industry continued to accelerate its development. Information released by the Geothermal Energy Association (GEA) in April 2011 indicated that in the next few years, the geothermal energy production in Texas in the United States is expected to double and geothermal power generation will Nine states expanded to 15 states. California is the state that uses geothermal power the most. Idaho is close behind. It is expected that by 2015, Idaho's geothermal power generation will reach 855 MW, and by 2025 it will reach 1670 MW. Since 2009, geothermal power generation in the United States has shown strong growth. From August 2008 to March 2009, there were 1,500 MW of new capacity under construction in the United States for geothermal power plants. If the geothermal resources stored underground in each state can be scientifically developed, it will be able to meet 25% of the country's total energy demand.

The United States ranks third among all renewable energy sources using geothermal energy, second only to hydropower and biomass, but it is more widely used than solar and wind energy. According to the statistics of the Geothermal Resources Association of the United States, the total amount of geothermal power generation in the United States has reached 2,200 MW, which is equivalent to the power generation of 4 large nuclear power plants. Today, geothermal pumps are beginning to gain popularity in the United States. About 50,000 users install geothermal pumps each year. This number will continue to grow as the US geothermal pump market continues to mature. With the increase of publicity, more and more people are beginning to understand this kind of energy that is abundant in the United States but has not been valued in the past. Under the premise that the demand for electricity continues to increase and the economic situation is not optimistic, heating methods that can save expenses are definitely welcomed by every family ^[1] .

It is worth mentioning that among clean energy, the cost of geothermal power generation is also relatively low. According to the analysis of the International Geothermal Association, the cost of geothermal power generation is only about half of the cost of wind power generation.

For this kind of energy with abundant reserves and outstanding advantages, the US government should naturally increase its use. Although the United States ranks first in geothermal power generation in the world, it is still not large in scale. Although there are some unresolved problems, which renewable energy is not the case? As long as we can achieve strengths and avoid weaknesses, we believe that geothermal energy will certainly occupy a very important position in the future energy structure of the United States.

Principles and advantages of geothermal heating and cooling systems

Geothermal is the thermal energy of the earth. Earth's soil can store solar thermal energy and not volatilize. This thermal energy is not affected by seasonal temperature changes below the frost line. By burying the geothermal converter under the frost line, the geothermal energy equipment can effectively use all the thermal energy stored in the soil. The specific operating party issued the following: bury the pipeline filled with ecological antifreeze solution into the surroundings of the house. These pipes are made of highly resistant polyethylene. As long as they are properly installed, they are not easily damaged and are hardly affected by harsh environments such as dry rot and extreme humidity. Geothermal energy converters can be placed horizontally and vertically. The system becomes flexible and can adapt to special ground conditions ^[8] .

Because the geothermal energy system is not affected by the outside air temperature, in cold weather, the heat-converting liquid in the underground pipeline can use the warm soil temperature to heat or cool the geothermal pump. The geothermal pump sucks the temperature-controlling solution through the underground pipeline, and transports it to the required place through the traditional pneumatic conveying pipe or polyethylene conveying pipe.

When cooling is needed, the geothermal system works with the low temperature of the soil. The system sucks in a temperature-controlling solution that can produce cold air, which is released to the house through a transfer pipe after it has been adjusted to the required temperature.

Geothermal heating and cooling systems are superior to traditional systems such as air source heat pumps and gas stoves. This is because traditional systems rely on outside temperatures that change dramatically with climate. The gap in their effectiveness is particularly noticeable under extreme temperature conditions. Under extremely cold conditions in winter and extremely hot conditions in summer, heating and cooling equipment need to operate at high intensity to ensure a comfortable temperature in the room, and the high costs are obvious. The geothermal energy system sucks in the outside air through a set of pipes made of high-density polyethylene buried deep in the soil below the frost line, which directly saves heating costs.