Saving energy at work
Audi is committed to conserving resources and protecting the environment – and this can only be accomplished with a dedicated workforce. One example is the Ingolstadt site.
In its vehicle production, Ingolstadt is well on its way towards becoming a CO2-neutral production site – a scenario in which the electrical and thermal energy that is used comes exclusively from renewable sources. Today, Audi already covers the electrical needs of its main facilities in Ingolstadt with green electricity from German and Austrian hydroelectric plants. This avoids up to 290,000 metric tons of CO2 annually. The overall efficiency of the factory’s own combined cooling, heat and power (CCHP) plant is extremely high at a value approaching 80 percent; natural gas boilers cover a portion of the remaining heat requirements.
Another energy source is district heat. Since 2004, the Ingolstadt site has been supplied with waste heat from the municipal waste incineration plant. In 2012, the next extension stage of the heating network went into operation; it obtained its waste heat from a nearby refinery. Overall, Audi utilizes at least 120,000 MWh of energy from waste heat annually; another extension stage is planned to produce a total of 200,000 MWh. Audi is also driving progress in the area of photovoltaics. Systems have been installed on several production hall roofs in Ingolstadt and Neckarsulm; they comprise a total surface area of 50,000 m2.
Audi can credit the dedicated actions of its employees for much of the progress made in achieving efficiency and resource conservation. “Our employees’ attentiveness and awareness of their responsibility are prerequisites for successful environmental protection,” says Peter Kössler, Plant Manager of Ingolstadt.
When employees have an idea for conserving resources in their work area, it is entered into the “green list.” Ideas generated within the energy-saving teams are also recorded there. In these teams, ideas are discussed openly, and this is where they get their support for practical implementation in production. All employees have the opportunity to present their proposals directly to management.
Such an idea was implemented in what is called a turning process. The mechanical machining of brake discs generates dust and heat. “We no longer blow the hot air outside,” stresses Reinhard Mayershofer, a technical specialist in brake disc production. “What was exhaust air previously we have now converted to recirculated air, and we utilize waste heat from the turning process to heat the production hall,” adds his colleague Bernhard Kerner. Converting the facility to operate with recirculated air has resulted in annual savings of around 582,000 kWh of valuable energy.
Another example is cathodic dip coating, a process in which vehicle bodies get their corrosion protection. To ensure that the paint material retains its quality, the dipping bath is fully recirculated once per hour. “The pumps must run continuously for this,” explains Erich Deinböck, production group leader in the paint shop. During production downtimes, a lower rate of recirculation suffices. Deinböck: “We now use frequency converters to reduce the rotational speed of the pumps. This lets us save around 24,000 kWh of electricity annually.”