Instead of gas from Russia: how to get home free energy from under the ground

But it is not necessary to dig into them to get thermal energy, because ordinary soil itself is well heated and retains a stable temperature regardless of the weather or season. The heat pumps use low -temperature geothermal energy stored deep underground for heating and cooling of buildings. The devices are similar to the more widely used air heat pumps that operate as air conditioning using fans and compressors to remove heat from summer buildings.

Unlike air conditioners, heat pumps also work on the reverse principle, delivering heat in the building for their heating in winter. They need electricity to work, but can receive it from sun or wind power plants and not depend on the central network. When the outside air temperature rises sharply in summer or sharply falls in winter, air heat pumps should operate more intense, which makes them less effective.

However, soil heat pumps usually receive heat together with a water -based solution from underground wells, drilled at a depth of several tens of meters, or special pipes buried just below the Earth's surface, where the temperature is about 55 degrees Fahrenheit (13 degrees Celsius) all year . In the summer, they, on the contrary, cool the room, removing heat underground, further heating the soil and storage of energy for the winter.

This makes them a highly effective source of heating and cooling throughout the year. The temperature of 13 degrees Celsius is not so high that people feel comfortable in the building, but the pumps pum a heat -conducting liquid solution into a special tank where it exchanges thermal energy with liquid refrigerant. Then this refrigerant turns into steam and compresses, as a result, its temperature rises.

As soon as this couple becomes hot enough, it enters the heat exchanger, where the air is heated and then fed into the rooms through the standard air duct system. According to the US Department of Energy Report, by 2035, geothermal heat pumps will be able to heat and cool about 7 million homes in the country, while today this figure is just over 1 million. The widespread introduction of technology will reduce the peak demand for 12 GW in summer and 40 GW in winter, US experts say.

This is equivalent to shutdown of dozens of coal or gas power plants during periods of high consumption. "In fact, they offer cost -effective heating and cooling solution, and the reason why it is important is that much of energy consumption in the United States and around the world is going to heat and cool the premises," Laure Boyde said, - said Head of the Department of Geothermal Technologies of the Ministry of Energy.

The rapid introduction of technologies for the extraction of geothermal energy interfere with high costs associated with drilling and laying pipes underground. In addition, you may need to install new air ducts or other equipment. Currently, in the US, the cost of installing a typical system for an apartment building is $ 19,000 after deduction of tax benefits, although the high cost is occupied over time due to its high efficiency.

The Ministry of Energy is convinced that to reduce costs it is necessary to create thermal energy networks, in which several buildings together use the heating and cooling system. Dozens of universities across the country have already installed such networks with soil heat pumps. According to Dandelion manufacturer, many geothermal systems are similar, but there are differences between them. Some use a closed or open system, a grounding pond or contours with a flexible coil.

There are pros and cons of different contour configurations for geothermal heating of buildings. Dandelion engineers use closed systems when U-shaped pipes are laid only under one house and are not connected to any external network. They consider them the most effective and safe option for households. The heat pump thus allows you to adjust the temperature as needed.

Instead of using large drilling plants, similar to the drilling of artesian wells, Dandelion uses small drilling storms that drill one or two deep wells with a few inches wide, where the pipes are then boiled. This system takes up less space and is mounted in a few days instead of weeks, saving money and time. Another thing is that many buildings can be combined into one network.

In 2024, Eversource Energy put into operation the first geothermal area in the United States, managed by the utility service, in Framingham, Massachusetts, reports Grist. The pipes were placed in wells with a depth of 600-700 feet (about 180-215 meters), where the soil temperature is constantly 13 degrees Celsius.

The mixture of water and propylene glycol (food supplement serving) rolls through the pipes and absorbs geothermal energy, heated, and then enters 31 residential and five commercial buildings, where completely electric heat pumps are used for heating or cooling. This geothermal system is extremely effective. It has a "productivity ratio" equal to 6, that is, each unit of energy consumed six units of heat. For comparison, gas stoves have a coefficient less than 1.

After installing the system, the home will be able to receive heat from the solution pumped from under the foundation, instead of being heated with cheap natural gas. The same equipment and even the same pipes as for gas pipelines are used to deploy the geothermal network - they simply pump fluid instead of gas. Networks do not require special geology, so they can be installed almost anywhere and gradually connect the area in the area.

This is a relatively new technology, so installation costs are still high. Eversource claims that its budget for the project was about $ 18 million. Most likely, as in the case of any technology, costs will be reduced as they improve and distribute. The transition from gas connections to network geothermal heating can reduce electricity costs by 15-20%, estimated by Eversource Energy. New Borobotic startup technology from Switzerland can reduce the cost of installing geothermal stations.