Cumulative energy consumption

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The cumulative energy consumption (KEV) is an application-oriented decision and evaluation indicator for services and goods in terms of sustainability . This practicable and meaningful parameter is often used to compare energy-consuming technologies. It provides information on the energy intensity of services and products and helps to make an informed selection on this basis. The KEV includes the balancing of the primary energies from the manufacture of the products or services to their use. "Thus the KEV is an orienting measure for the energy-related environmental pollution".

Definition of KEV according to the Federal Environment Agency and demarcation from KEA

The cumulative energy consumption (KEV) is made up of the sum of all primary energies used in the production and use process of a product or service including all upstream chains minus the materially used energy sources such as wood for construction purposes or crude oil for plastics, etc. Expenditures do not take place in the KEV, but in a separate raw material balance in which the quantities are recorded. The disposal costs are also not included in the KEV. In terms of formula, the KEV is to be calculated as follows:

KEV = ∑ of all primary energies for production and use purposes including upstream chains - ∑ of all materially used energy carriers

According to VDI guideline 4600, the main difference to the cumulative energy expenditure (KEA) is that only the quantities of energy actually used or “consumed” are included. In the KEA, the material quantities of energy used as well as disposal costs or credits for energy recovery (e.g. burning waste wood in biomass incineration plants) are therefore also taken into account, since energy quantities must be promoted or provided and increase the calorific value of the final output.

Example applications in practice

  • KEV as a decision parameter in the sustainable renovation of residential buildings
  • KEV as an evaluation indicator for sustainable building and living as well as for sustainable consumption
  • Comparison of incandescent lamps and compact fluorescent lamps
  • Comparison of washing machines with / without hot water connection
  • Discussion of different ways of disposing of household waste
  • KEV as a decision parameter in solar settlements
  • Food production in agriculture, e.g. B. Bread production
  • Traffic evaluation of local passenger traffic and long-distance freight transport
  • Cumulative energy consumption and harvest factors of photovoltaic systems

Examples of relevant KEV orders of magnitude

  • The KEV of public transport is only about half as large as that of the car (with medium utilization)
  • The proportion of vehicle provision in the KEV is 13% for buses and cars and around 4% for trams
  • KEV incandescent lamp (GL) / compact fluorescent lamp (KL) (assumptions: same light intensity, service life KL = 1500 h and GL = 1000 h):
GL KL 15 bulbs
KEV (production) in GJ 0.003 0.014 0.045
KEV (use) in GJ 1,145 3,344 17.175
KEV (total) in GJ 1.148 3.448 17.220
  • KEV of a photovoltaic module (η = 15.5% and monostructure of the silicon) in about 11,000 kWh / kWp
  • KEV of a photovoltaic module (η = 13.5% and multi-structure of silicon) in about 7500 kWh / kWp

See also

Individual evidence

  1. ↑ a b c d UBA (ed.) (2003): Application and communication of the cumulative energy consumption (KEV) as a practicable, environmentally-related evaluation and decision indicator for energy-intensive products and services - short version, Berlin 2003, p. 1
  2. ↑ a b Association RENEWABLE ENERGY (1994/1996): Cumulative energy consumption and harvesting factors of photovoltaic systems

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