Waste heat refers to excess thermal energy generated as a byproduct of industrial processes, in power plants, transportation systems, and building technology. It primarily occurs in the form of hot air, exhaust fumes, steam, or heated liquids and is often released into the environment without being utilized. This represents lost energy that, in theory, could be recovered but is in practice frequently wasted. As a result, waste heat is increasingly being recognized as a valuable energy source, especially in the context of resource conservation and energy efficiency.

Sources of waste heat

Waste heat is produced in a wide range of processes, from industrial operations to everyday activities. Common sources include manufacturing processes, the operation of machinery and engines, electricity generation in power plants, and even household appliances. A significant portion of the energy used in these processes is converted into heat, which, if not recovered, is lost through exhaust gases, waste water, or other heat transfer mechanisms.

Recovery and utilization of waste heat

In recent years, technologies for waste heat recovery and utilization have become increasingly important. These systems enable excess thermal energy to be captured and repurposed instead of being lost to the environment. Typical applications include heating buildings, feeding into district heating networks, or supplying process heat for industrial use. Industrial high-temperature heat pumps such as the ThermBooster exemplify efficient waste heat utilization. These systems harness industrial low-temperature waste heat to generate steam or hot water at temperatures of up to 200°C.

Benefits of waste heat utilization

Reusing waste heat significantly reduces overall energy consumption, leading to lower operating costs and a reduced environmental footprint. This is particularly beneficial in energy-intensive industries such as steel or cement production and processing, food processing, as well as textile, pharmaceutical, and paper production, where efficient waste heat utilization can make a substantial contribution to the sustainability of these processes. Additionally, recovering waste heat helps cut CO₂ emissions by reducing the demand for primary energy from fossil sources. By integrating high-temperature heat pumps, some industrial processes can even be fully decarbonized.

In summary, waste heat represents a valuable energy resource that will play an increasingly crucial role in achieving climate targets and improving energy efficiency. From a business perspective, waste heat recovery is also a key factor in cost reduction: In energy-intensive operations, it provides significant savings on energy expenses while enhancing overall sustainability.