You might have seen people rubbing their hands together on a cold winter night to get some warmth. Have you ever wondered what exactly happens in this process. How does rubbing your hands induce a sense of warmth? The fact of the matter is the mechanical energy that you spend on rubbing your hands is converted into thermal energy, which causes an increase in temperature, making our hands warm. We will explain the concept of thermal energy more lucidly in the following paragraphs.
... Thermal Energy
- Temperature and heat are the parameters that govern the inherent thermal energy of an object.
- Temperature is defined as the average kinetic energy of all the atoms and molecules in an object.
- A very basic definition of temperature is the degree of hotness or coldness of an object. When we touch a hot plate, what flows from the plate is heat energy.
- So, heat is defined as flow of thermal energy from an object at higher temperature to an object at relatively lower temperature.
- Thermal energy is defined as a form of kinetic energy that occurs due to the motion of molecules in a system. Thermal energy results from vibrational, rotational and oscillatory motion of atoms and molecules that constitute substance.
- Kinetic energy is the energy that a substance possesses on account of its motion. Therefore, we can conclude that thermal energy is a manifestation of kinetic energy of atoms and molecules.
- Thermal physics is the branch of physics that deals with the physical process that involve changes (increase/decrease) in the temperature of the system.
- In any case, thermal energy is just a part of the internal kinetic energy or thermodynamic energy of a system, and it is often confused with total internal energy of the system which is the sum total of internal kinetic energy and potential energy of the system.
- The random motion of molecules can be described with the help of Kinetic theory of matte.
- According to this theory, matter comprises atoms and molecules in random motion and while moving from one place to another, these particles transfer their kinetic energy to nearby particles.
- The relation between thermal energy and the Earth is simple, the sun is the natural source of energy to the mankind. Energy in the form of heat and light is transferred from the sun to earth to sustain life on this planet. Energy from the sun is called radiation and when it reaches the surface of the earth, it is known as heat.
- At some basic level, it is created in many aspects of our daily lives. Burning, for instance, is a very simple form of heat-producing reaction. Energy in nuclear reactions and motion of electrons in electrical circuits are some other examples where this form of energy is created in the process.
- The word 'geothermal' is a combination of two Greek words - geo which means earth, and thermal which means heat.
- Geothermal energy is the form of energy that is present as heat energy inside the surface of the earth.
- For every 100 meters you go inside the surface of the Earth, the temperature increases by about 3°C. The temperature at the earth's crust is as high as 5,500°C.
- Geothermal energy continuously flows towards the surface of the earth through volcanoes, hot springs, and geysers.
- The pollution caused due to geothermal energy is minimal as only small amounts of sulfur and carbon dioxide are released into the atmosphere.
- The first geothermal plant in the world was built at Larderello, Italy. The plant is in use even today.
- The geography of a region plays an important part in determining whether geothermal energy can be viably harnessed as an energy source. Regions which have a history of volcanic eruptions and earthquakes are most suitable for geothermal plants.
- This form of energy can be extracted from the earth's surface through the process of dry steam, flash steam, and binary power plant.
- United States of America has 40 geothermal plants and the government is planning to come up with more plants in the next couple of decades.
- In many countries, geothermal energy is a major source of power, and is used chiefly for home heating. In fact, there are more than twenty countries which use geothermal energy for their energy needs. Some of these countries are USA, Italy, Iceland, and Russia. Around 30% of electricity in Iceland is generated from geothermal energy.
- Solar thermal energy is not a natural form of energy, but is a type of technology used to harness thermal energy with the help of the available solar power.
- Solar thermal power is one of the most common forms of thermal energy and its energy is used in solar panels, evaporation systems, etc., for harnessing solar energy.
- Solar thermal energy is one of the oldest forms of energy that was harnessed by humans. It is widely believed that Archimedes' used this form of energy to burn invading Roman ships.
- It is one of the most affordable modes of energy. As solar energy is renewable, the only cost involved in harnessing this energy is the cost of manufacturing and installing solar thermal panels.
- It has been estimated that if used properly, businesses can save around 40% of their electricity bills by switching to solar thermal energy.
- Solar thermal energy can be used in conjunction with other sources of energy, and can be used to lower the costs associated with fossil-fuels.
- It doesn't cause any pollution, and doesn't contribute to the greenhouse effect.
- The continent with the highest solar energy radiation is Australia.
- According to research, one megawatt hour (MWh) of electricity produced due to solar thermal energy prevents the emission of a ton of carbon dioxide in the atmosphere.
As we know that global warming is a burning issue for all the countries of the world, the governments are looking at other alternative sources of energy. Research on harnessing thermal energy in the form of solar and geothermal energy is going on in many countries, and thus, it can become one of the most important sources of energy in the near future.