Gray energy

As embodied energy is the amount of energy referred to for production , transportation , storage , sale and disposal of a product is needed. All preliminary products up to raw material extraction are taken into account and the energy consumption of all production processes used is added up. If machines or infrastructure facilities are required for production , the energy requirement is usually also requiredfor their manufacture and maintenance included proportionally in the "embodied energy" of the end product. The “product” can also be a service . Embodied energy is thus the indirect energy requirement when buying a consumer good , in contrast to the direct energy requirement when using it. The cumulative energy expenditure (KEA) summarizes these sub-areas.

Orders of magnitude

The Federal Statistical Office of Germany calculated that in 2003 the average energy intensity of all goods excluding energy goods was 4.5 MJ / EUR. I.e. On a macroeconomic average, every euro that an end consumer spends causes around one kilowatt hour (= 3.6 MJ) of "gray energy" (excluding direct purchase of energy).

The energy intensity varies greatly depending on the goods group. According to the Federal Statistical Office, the following groups were most exposed to indirect energy demand in 2003: aviation (25.7 MJ / EUR), other transport (16.3 MJ / EUR) and chemical products (11.8 MJ / EUR).

Examples

Single products

• 1 kg of chocolate : 2.5 kWh
• a pair of shoes : 8 kWh
• two aluminum cans: "Daily electricity requirement of a four-person household" (ie approx. 10 kWh); see also: Aspects of the life cycle assessment in aluminum production
• 500 sheets of copy paper bleached without chlorine: 41 kWh ;; see also: Environmental aspects and recycling of paper
• 500 sheets of copy paper recycled: 28 kWh
• Daily newspaper (90 pages): 7.5 kWh
• Production of a personal computer : 3,000 kWh (plus 1.5 tons of raw materials); see also: Resource Consumption in the Production of Personal Computers
• White goods : Depending on the device, around a third to a quarter of the direct energy requirement over its service life
• an automobile : “Electricity needs of an average household for 10  years ” (about 30,000 kWh); see also: Environmental and health aspects in the manufacture and operation of automobiles
• the provision of one liter of diesel at the pump required up to 20% additional fuel consumption
• VW Golf A3 ( petrol engine ): around 18,000 kWh (12% of 545 GJ)
• VW Golf A4 ( TDI engine ): around 22,000 kWh (15% of 545 GJ)

Difficulty calculating

The process chain for most products is quite complex, so that simplifying assumptions have to be made when calculating the embodied energy . Concrete figures for the gray energy content of a product are accordingly uncertain, differ depending on the source or calculation method and are often controversial. In addition, the concept of embodied energy cannot be precisely defined. a. expresses itself in the occurrence of delimitation problems such as:

• Does it make sense, for example, to transfer the energy requirements of the company canteen to the products (produced in this company)?
• Should all products that are transported on the road also be assigned a share of the energy requirements of the hospitals in which injured people are treated after traffic accidents?
• Why, for example, are only the amounts of energy used for extraction included in oil production , but the losses from flaring the associated gases only included in environmental analyzes?

Gray energy in Switzerland

In Switzerland, "gray energy" corresponds to "primary energy not renewable".

literature

• Daniel Spreng: How much energy does the energy need? Energy balances of energy systems , VDF - Verlag der Fachvereine , Zurich, 1989, ISBN 3-7281-1647-5 .

Web links

• Process-oriented basic data for environmental management instruments (ProBas) - online database covering a wide range of life cycle data
• GEMIS: "Global Emissions Model of Integrated Systems" - a freely accessible software under Windows for calculating energy, transport and material flows, including the accumulated energy consumption
• Gray energy - what is it? (Explanatory film)
• Federal Office for Energy, Switzerland
• Eco-bau association, Switzerland

Individual evidence

1. ↑ Federal Statistical Office Germany: The use of environmental resources by the consumption activities of private households , Chapter 7 (Indirect and cumulative energy use of private households)
2. ↑ ^{a b c d} Austrian Federal Ministry for the Environment, Youth and Family : “Using energy instead of wasting it” (around 1997), page 21
3. ↑ ^{a b c} Practical Environmental Protection Switzerland ( "PUSCH", a non-profit organization ): "Embodied energy Paper" ( Memento of 17 September 2007 at the Internet Archive ) (page 10) in the Internet Archive , accessed 14 April 2011 (converted values)
4. ↑ Green IT: How to make your computer green from February 28, 2008 at Spiegel Online , accessed April 14, 2011; Spiegel Online refers to a value given by the Wuppertal Institute for Climate, Environment and Energy .
5. ↑ Esther Widmann: Eco-Series: Old electrical appliances - replace or not? August 25, 2017, accessed on November 26, 2019 (the author refers to studies by the Öko-Institut Freiburg, as well as statements from the Federal Environment Agency, consumer advice center and other experts). 
6. ↑ ^{a b} Information on energy and material requirements for the production and operation of a motor vehicle in the Volkswagen Environmental Report 2001/2002 (German) ( Memento of the original from March 3, 2016 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. from Volkswagen (page 27), accessed on April 14, 2011 ( PDF ; 3.9 MB). Note: The percentage refers to the 545 GJ converted in the entire product life - the majority of the total amount of energy is attributable to fuel consumption during use.