Purchasing Environmentally-Friendly Plants
Machines and processing plants are generally too complex to certify them in their entirety as environmentally friendly. It is significantly easier to subject components such as drives or fans to this inspection. Now, the German technical inspection association TÜV SÜD has developed an inspection seal for the energy and media efficiency of large plants. This seal is only awarded, however, if specifications are exactly complied with and documented.
Statutory regulations specify, for example, limits for emissions and waste water. But the legislator does not prescribe how much energy a machine is to use. "That's more a question of cost", explained Dirk Schäfer, Managing Director of the management consultancy Kerkhoff Consulting. In view of the increasing energy prices, environmental protection and cost reduction are not mutually exclusive – quite the contrary. "The conversion from oil to gas may even be worth it for existing production plants." However, such major investments should also be made before the backdrop of political developments.
Companies which champion the cause of environmental protection and want to be markedly above statutory requirements should carefully examine the components of their plants. "This includes an examination of the sub-suppliers", advised Schäfer. For him, offering parties seem not to be very reputable if they do not provide information, for instance, on whether the sub-supplier exclusively purchased uranium-free steel and whether only nontoxic materials have been used in production. Automatically supplied are merely technical data, such as dimensions, weight, suction capacity or torque. "In contrast, the buyer often needs to ask specifically for any data on environmental compatibility", according to Schäfer. Incidentally, the same is also true for used machinery.
Clear Requirements in Performance Specifications
In order to ensure that potential suppliers submit comparable offers, important criteria such as energy and water consumption, emissions and service life should already show up in the invitation to tender. "Based on these performance specifications, the buyer will later be able to simply compare the factors in a table", said Schäfer. In order to correctly formulate these requirements, support is required from the appropriate technical department: Because only that department will be able to decide whether, for example, an explosion-protected three-phase induction motor in combination with frequency converters must have the energy efficiency class II2 or II3.
Frequently, certain components are not necessary at all or too large in their dimensions. "No matter how energy-efficient a particular component is – if a hydraulic pump, for example, is operated in a partial load range and at low efficiency, unnecessary costs will be incurred", said Heuß. The standard series ISO 14000 includes important requirements. Regulated therein are audits, environmental declarations, measuring procedures, all the way to the ecological assessment. In sectors of the industry with particularly high energy demands, energy management according to ISO 50001 should absolutely be provided in any case. This will not only serve controlling within the company – power consumption is also an important basis for calculating the EEG levy (EEG - German Renewable Energies Act). Starting at a consumption of ten gigawatt hours per year, the certificate is mandatory in order to apply for a reduced EEG levy.
Optimization of Energy-Intensive Plants
One example for energy-intensive enterprises is the production of aluminum. The purchase of a new smelting furnace is a challenging matter because large thermal processing plants are running an average of 25 to 30 years. Machine tools are replaced already after about ten to twelve years, and robotic systems in the automotive industry still faster. "Even if suppliers indicate how many kilowatt hours of electricity or natural gas are required for one ton of aluminum melt – the comparison remains difficult", emphasized Heuß. Additionally, it would have to be examined which operating parameters were assumed as the basis for consumptions of energy and resources.
For example, the waste heat of a furnace may be used for preheating in a secondary process. "Due to the installation of a heat exchanger, efficiency values will be improved", according to Heuß. For him, a holistic view of processes and documentations is more important than the focus on kilowatt hours of an individual machine. For example, if a company were to do without compressed air or have it optimized for specific production steps – such as drying or cleaning – this could improve processing security. The result: lower consumption, less noise and reliable production.
At least there is now one seal dealing with complex plants or systems: The Energy and Media Efficiency, Environmental Sustainability (EME) seal from TÜV Süd will only be given to machines and plants for which concrete data and unbroken documentations are provided. The catalog of criteria has been deposited in a systematic and structured form – from components all the way to the system level. "If a plant deviates from parameters which are relevant for energy and media efficiency, it will not obtain the certificate." Heuß advocated to connect production planning, purchasing, production, machinery service, supply engineering, buildings and maintenance. "That's when a production company can really be operated in an energy-efficient and environmentally compatible manner."