What Is Thermal Energy?

Turbine engine
Turbine engine

As evidence accumulates in support of climate change and its effects, you may wonder, "What is thermal energy?" and if it's a viable alternative to fossil fuel. Like other forms of renewable energy, such as wind and solar energy, thermal energy is being used as an alternative form of energy.

What Is Thermal Energy?

At its most basic level, thermal energy is energy in motion, which is known as kinetic energy. This energy is created from the movement of atoms and molecules. Although invisible to the naked eye, these particles constantly move and generate energy.

The movement creates friction, which in turn creates heat. When you detect heat, you are feeling the effects of thermal energy in transit. The motion of atoms and molecules increases with the temperature. The sun is a perfect example of thermal energy and heat transfer. According to the first law of thermodynamics, energy cannot be created or destroyed. Instead, it converts or transforms into different forms. It is this basic chemistry principle that allows thermal energy to be adapted and developed as a source of alternative fuel.

Combining Heat and Power

Using thermal energy increases the efficiency of industrial processes that generate heat. Combined heat and power (CHP) makes use of the heat generated from chemical processes to provide power to run other equipment. A common example is a wastewater treatment facility.

Decomposition of waste products in water involves anaerobic digestion of contaminants, which in turn produces biogas. This biogas is then used within the facility to run generators for other equipment. The immediate benefit is a reduction in energy costs.

The facility takes advantage of this "free" energy to run its own equipment, while reducing the emissions it produces and diminishing its environmental impact. The facility saves on energy costs and the environment benefits from the reduction in greenhouse gas emissions. This technology is widely used by industrial manufacturers, institutions, and commercial buildings.

Fuel Cell Technology

The energy generated from thermal energy can also be harnessed within fuel cells. A fuel cell produces energy from a chemical reaction that occurs in its electrodes. An electrolyte carries the ions or charged particles as a result of the reaction between one electrode and another that produces a current. Just as with CHP technology, any heat given off from the reaction is captured and used to increase energy efficiency.

Current technology does not allow for widespread energy generation from fuel cells. However, fuel cell technology does have applications for single projects such as multi-family dwellings, office buildings and schools. In these scenarios, a fuel cell supplements energy usage and in turn, drives down electricity costs.

Ocean Thermal Energy Conversion

Thermal energy has other applications, such as ocean thermal energy conversion (OTEC), which uses the same principles with the temperature gradients in the ocean to generate electricity. Primarily a marine technology, OTEC has the advantage that it is constant and reliable, according to the National Oceanic and Atmospheric Administration (NOAA). The temperature zones within the oceans are stable due to the large volume of water. Considering that 70 percent of the Earth's surface is covered in oceans, the potential for using OTEC is enormous.

Geothermal Energy

Like oceans, liquid rocks in the Earth core is another source of constant thermal energy that offers the same advantages as other renewable energy alternatives. Geothermal energy involves extracting heat from underground in the form of steam and then using this heat to generate energy.

The application is limited by geology. That means that extraction is only feasible in certain areas of the country. This type of energy does not produce greenhouse gas emissions or generate any solid waste. Water discharges are controlled to prevent contamination of water surfaces, such as lakes and streams that supply drinking water.

Understanding Thermal Energy

What is thermal energy? It is a pathway toward producing energy that is clean, reliable, and renewable. It represents another form of technology that can help reduce the amount of greenhouse gas emissions emitted into the atmosphere. As the global community develops solutions for climate change, thermal energy remains a viable alternative.

What Is Thermal Energy?