It seems not a day goes by without us hearing the buzz word “energy efficiency.” We see energy effi ciency labels on products on store shelves in specialty departments selling things like consumer electronics. Even in industry, the issue of energy effi ciency is ubiquitous, guiding our decision making at every turn. Prof. Dr. Georg Kleiser, head of the Steinbeis Consulting Center for Energy-Efficient Manufacturing, explains the various aspects that companies should consider when it comes to energy effi ciency.
In addition to how this topic is being pushed in product marketing, legislation is forcing companies to think about the issue through energy audits and the introduction of energy management systems. Some of these measures are backed by government incentives promising reimbursements on energy costs. The prevalence of this topic in the public eye coupled with corresponding standards and laws shows us that longterm production strategies aimed at resource conservation cannot be achieved without considering energy effi ciency. But how important will energy effi ciency remain in the future as part of a resource effi ciency strategy? And what are the challenges we might face as a result?
The growing environmental awareness from the 1980s/90s and the resulting implementation of environment management systems in the planning and control of manufacturing systems cast a spotlight on the issue of energy management and the role it plays in optimizing companies from the inside out. Corresponding tools and standards such as management systems, typically aligned with DIN standard ISO 14001 and the European Energy Management and Audit Scheme (EMAS), point to energy consumption as a central environmental factor, one which should be duly documented and minimized. In keeping with the general aims of environmental management systems, the primary focus has been on “achieving environmental protection by preventing or reducing damaging effects on the environment.” This means energy consumption is quickly equated with its impact – harmful emissions – as an environmental indicator. The most harmful of these effects are carbon dioxide emissions, often cited as the cause of the greenhouse effect. Energy, in this respect, has been primarily looked at in terms of fi nal energy consumption, which only in some cases, to get a more detailed analysis, was subdivided into electricity and fuel.
In the meantime, the global rise in signifi cance of the greenhouse gas problem has led to increasing pressure to reduce energy-related carbon dioxide emissions. This is evident, for example, in the introduction and continual application of eco-design guidelines and newly established national energy savings plans (which also lay down target requirements for trade and industry). As the issue becomes more relevant, people are now placing greater value on energy management, which has led to the rise of ongoing standards for using energy as an economic commodity. For example, since 2012, we have had the DIN standard ISO 50001 as a guideline for establishing and applying energy management. The main focus in this area lies in organizations and internal company processes. The process of quantifying energy fl ows and discovering potential savings as part of audits are standardized under DIN standard 16247. The German energy service provision act (EDL-G) makes it mandatory for companies to set up an energy management system or carry out audits in line with the standards named above. This applies to all companies not classed as SME.
In the past, implementing these measures and meeting these requirements was a big challenge for companies. This led to strong demand for consulting services in the field. Manufacturing systems are defined by the advanced need for various energy services. In production processes, “work” is actually needed to transform products (i.e., to change the nature of a product) or for transportation (i.e., to convey the end product). This work is either provided through electrical power or through additional energy carriers such as compressed air or hydraulic systems. There is also a need for process heat as a useful energy source and this is needed to affect chemical reactions and phase changes such as melting and evaporation. The need for process heat is also often satisfied through additional energy sources such as steam or hot water.
In addition to the actual requirements for work and heat in the manufacturing process itself, there are other energy demands related to the manufacturing process and these also have to be met. This includes heating and lighting of production halls and providing energy for communication technologies. Energy consulting and state-funded programs for investment projects have previously only focused on the energy consumption in actual manufacturing or energy conversion processes immediately upstream or downstream of production. These are often referred to as cross-sectional technologies, since they are universal in many branches of industry and because they employ similar technologies. This focus initially seems reasonable for the following reasons: Most consultants have expertise in building or facility technologies, or in individual energy supply technologies such as compressed air or cooling, so as a result, these are the primary focus of consulting services. Furthermore, agencies offering funding programs are tasked with driving broader investment, making funding options available in all industries. As a result, they avoid tenders that are too highly specialized or ones that relate to individual production processes and sectors of industry.
Far-reaching, future-oriented energy efficiency optimization – even as part of holistic resource efficiency strategies – should take the following points into account: The first lever in optimizing energy efficiency is the actual manufacturing process. For example, there is no sense in optimizing the compressed air provision in bulk cargo transportation if the overall logistics concept within the manufacturing system is inconsistent. Energy optimization has to lie at the heart of the production process, at the actual point of energy requirement. As a result, a central lever for achieving energy efficiency lies in optimizing throughput. Since many auxiliary machines have high energy demands, even when they are running at partial load or are idle, specific energy demands sharply increase at low-capacity production. Energy conservation measures may be well-intended, but they can also threaten production or batches, or even have a negative impact on material efficiency, so in such cases they should be avoided from the start. The only way to save energy overall, is to conduct a holistic assessment of energy flows, including the supply chain. It is also important to consider material consumption when it comes to energy use. This is only possible if holistic life cycle assessments (LCAs) are carried out and various production methods are compared under the same scenarios. Cumulative energy demand (CED), which in essence is about conserving energy resources, can be used as an indicator to compare various forms of energy consumption. As an alternative, global warming potential (GWP) can be used. This allows for a comparison of processes and technologies with respect to their negative impact on global warming.
Society’s desire to minimize global warming has given the topic of energy efficiency a big push in the right direction. The general scarcity of our resources and the development of completely new technologies and processes (which are accessible globally thanks to the Internet), are shifting the topic back in the direction of overall manufacturing optimization, taking all used resources into account. Specialists should focus their expertise on combining technical and manufacturing know-how with the methodological skills needed to evaluate respective systems, and this should be given a greater priority by universities of applied sciences and the providers of consulting service. This is the only way to ensure that we meet political aims and the need to reduce greenhouse gases and improve resource efficiency.
Prof. Dr. Georg Kleiser heads up the Steinbeis Consulting Center for Energy-Efficient Manufacturing at the University of Applied Sciences in Ulm and offers his customers consulting on increasing energy efficiency in trade and industry. He also offers evaluations and analysis of energy efficiency measures as well as energy optimization in manufacturing processes.
Prof. Dr. Georg Kleiser
Steinbeis Consulting Center Energy-Efficient Manufacturing (Heubach)