The Energy Efficiency Act (EnEfG) is a key instrument of the German climate protection strategy and was developed to reduce energy consumption and increase the efficiency of industrial processes. In view of increasing regulatory requirements, companies in energy-intensive industries are obliged to implement measures to reduce their energy consumption. A key technology for achieving these goals is heat recovery (HR), which makes unused waste heat from industrial processes available for reuse. This article describes the significance of heat recovery in the context of the EnEfG and the technical and economic aspects, challenges and solutions for companies.
The Energy Efficiency Act (EnEfG) in detail
The EnEfG was developed in response to rising energy prices, the need toreduce CO2 emissions and the growing dependence on fossil fuels. It defines binding savings targets for companies and sets clear framework conditions for the implementation of efficiency measures. The key points of the law include
Energy saving obligation: companies with a final energy consumption of more than 2.5 GWh per year are obliged to take economically viable measures to save energy. In particular, this includes the use of waste heat with a temperature level of over 20 °C, provided it is economically viable.
Obligation to use waste heat: Companies must identify and document the waste heat generated in their processes and take measures to use this energy. Heat recovery plays a key role here, as it is one of the most efficient ways of saving energy.
Mandatory reporting: Companies are obliged to collect data on their waste heat sources and publish it on a publicly accessible platform. This is intended to facilitate the use of surplus heat by other companies or municipal energy suppliers.
Obligation to introduce an energy or environmental management system: Companies with an energy consumption of more than 7.5 GWh must introduce a standardized management system to ensure continuous improvements in the area of energy efficiency.
These regulations make it clear that heat recovery is a key measure for meeting the legal requirements.
Typical exhaust air scrubber with heat recovery in horizontal design - (Photo: Calorplast)
Heat recovery in the electroplating industry
The electroplating industry is one of the most energy-intensive sectors in which considerable amounts of waste heat are generated. A lot of energy is lost through the operation of open process baths, which are often constantly heated, as well as through the ventilation systems used to remove chemical vapors. In Germany, there are around 1,600 to 1,800 electroplating companies that operate both as contract coaters and in-house electroplating plants.
Medium-sized electroplating companies with between 70 and 100 employees generally have an annual energy consumption of 5 to 10 GWh, which means that they clearly fall under the regulations of the EnEfG. Without targeted measures for waste heat recovery, a large proportion of the energy used escapes unused into the ambient air, which is both ecologically and economically inefficient.
Technical solutions for heat recovery
Vertical exhaust air scrubber from Koerner Chemieanlagenbau in Austria. This scrubber also contains a heat recovery system. The aggressive exhaust air is washed; enriching the air with water results in a higher energy potential for recovery - (Photo: Kvk Koerner)Heat recovery in electroplating can be achieved using various methods that aim to use waste heat efficiently and significantly reduce energy consumption. Different technologies are available depending on the system structure and operational requirements:
Exhaust air heat recovery: this method uses gas-water heat exchangers or circulation systems to use the thermal energy in the exhaust air to preheat the fresh air. The heat contained in the exhaust air is transferred to the supply air through a heat exchanger, significantly reducing the amount of heat required to heat the production hall. Particularly in the electroplating industry, where large volumes of air are moved, gas-water heat exchangers can recover up to 70 % of the exhaust air heat with a high degree of efficiency. Circulation systems also prevent contamination between exhaust air and fresh air, which is particularly beneficial in chemically contaminated environments.
Heat pump integration: By integrating a heat pump, the energy recovered from the exhaust air can be made available all year round - even outside the heating period - for a wide range of applications.
These solutions offer enormous potential for energy savings and generally pay for themselves within one to five years, depending on the existing infrastructure and the technology used. Selecting the optimum heat recovery solution requires a careful analysis of the operational conditions in order to identify the most economically and technically viable measure.
Challenges and solution strategies
Despite the considerable advantages of heat recovery, there are a number of challenges when implementing such systems. These mainly relate to technical, financial and administrative aspects, which present companies with a complex decision-making process. The most important challenges and suitable solutions are presented below:
Technical adaptations
Existing ventilation and heating systems are often not designed for the direct integration of heat recovery systems. Older production facilities in particular often lack the necessary infrastructure for efficient heat transfer. This can mean that additional pipes, heat exchangers or special control systems have to be installed in order to make sensible use of the recovered heat.
Solution: A detailed inventory of the existing system technology is essential in order to identify the optimum interfaces for the integration of a heat recovery system. Implementation can be facilitated by using modular gas-water heat exchanger systems that can be flexibly adapted to existing processes. In addition, modern control systems can ensure that the recovered heat is distributed as required.
Gas-water heat exchanger from Calorplast with cleaning device and droplet separator - (Photo: Calorplast)
Investment costs
Although heat recovery systems generally pay for themselves within a few years, the initial investment costs represent a financial hurdle for many companies. Depending on the size of the business and the scope of the measures, the acquisition costs for heat exchangers, pipes and control technology can vary considerably.
Solution: Companies should carry out a profitability analysis in order to transparently demonstrate the return on investment. In many cases, a step-by-step implementation can make sense, in which the areas with the highest savings potential are converted first.
Documentation and reporting obligations
The EnEfG stipulates that companies must prepare detailed reports on their waste heat usage and update these regularly. However, recording and documenting energy flows can be an administrative burden, especially for smaller companies that do not have the necessary internal resources.
Solution: By using digital energy management systems, waste heat usage and energy savings can be automatically recorded and evaluated. These systems enable continuous monitoring and help companies to meet legal requirements efficiently. In addition, cooperation with external energy consultants can simplify documentation obligations and ensure that all regulations are complied with.
Exhaust air system in a laboratory environment - (Photo: Colasit AG Spiez)
Training and raising employee awareness
Another important factor for the successful operation of a heat recovery system is employee awareness and training. Without clear communication about the benefits and operation of the systems, the efficiency of heat recovery can be compromised.
Solution: Companies should provide regular training and information sessions for their staff to create a basic understanding of heat recovery and its importance to operations. A clearly defined energy management system with fixed responsibilities can help to ensure the efficiency of heat utilization in the long term.
Technical development in electroplating
The electroplating industry has made considerable technological progress in recent years, particularly in the area of energy efficiency and sustainability. New materials, innovative coating processes and improved process control have already helped to reduce energy consumption and environmental impact. The implementation of digitalized control systems in many companies has made production processes more precise and enabled optimizations, resulting in more efficient use of chemicals and energy. At the same time, product quality has continued to improve.
One promising development is the increased use of closed-loop systems for the targeted recovery of waste heat in order to feed it back into the production process. While some companies have already successfully implemented this technology and have been able to reduce both energy costs andCO2 emissions, many companies still face the challenge of making the necessary investments and meeting regulatory requirements.
The combination of advanced heat recovery systems, optimized plant technology and strict environmental regulations is increasingly making electroplating a sustainable and resource-conserving industry. This trend is expected to continue as both economic and environmental requirements drive companies to continually invest in innovative technologies. Nevertheless, some of the predicted advances have not yet been realized across the board, so the complete transformation of the industry will still take time.
Circulation system (left) with hydraulically connected supply and exhaust air and Evolution heat exchanger from Calorplast (right), a gas-water heat exchanger that can be easily integrated into systems due to its modular design - (Photo: Calorplast)
Conclusion
The EnEfG sets clear requirements for waste heat recovery and makes heat recovery a central element of the energy efficiency strategy in industry. In the electroplating industry in particular, there is considerable potential for reducing energy consumption through heat recovery systems.
Companies should consider heat recovery as a sustainable measure to improve energy efficiency and take measures to implement it at an early stage. Through the targeted use of waste heat, not only can legal requirements be met, but considerable economic benefits can also be realized and a significant contribution made to climate protection.
This article is based on a presentation given by Calorplast employee Johannes Flore at the Leipzig seminar.
