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, the Ingolstadt plant is well on its way towards becoming a carbon-neutral production site – a scenario in which the electrical and thermal energy that is used comes exclusively from renewable sources. Today, at its main facility in Ingolstadt Audi already meets its electrical needs with green electricity from German and Austrian hydroelectric plants, thus avoiding 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 utilises 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 encompass a total surface area of 50,000 m2. In Ingolstadt an area of more than 23,000 m2 is available for photovoltaic modules. The total yield of the Ingolstadt plant’s photovoltaic systems amounts to some 1,800 MWh per year. Around 40 percent of that is utilised on site – by production facilities, for example – with no transmission losses.
At the Győr site, since autumn 2015 the new geothermal energy plant has been meeting around 60 percent of heat requirements. Damit kann der CO2emissions at the location by a further 19,800 metric tons annually.
In Sant’Agata Bolognese, Automobili Lamborghini S.p.A. commissioned a new CHRP plant in 2015. In addition, the Italian subsidiary has been tapping surplus waste heat from a nearby biogas plant since 2015. Both measures bring about a significant reduction in CO2 emissions.
Audi can credit the dedicated actions of its employees for much of the progress made in achieving efficiency and resource conservation. 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. Here the 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 utilise 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: vehicle bodies get their corrosion protection in a process known as cathodic dip coating. 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 inverters to reduce the rotational speed of the pumps. This lets us save around 24,000 kWh of electricity annually.”