Environmental Calculator:

General Overview of Background and Methods

To be able to weigh out such alternatives against each other, the section 'Environmental Calculator' is used. It relies on a database with figures representing a simplified environmental impact assessment, using two parameters to describe the impacts (e.g. by using an integrated circuit, x gram of aluminium or consuming y kWh of electricity):

• The Energy parameter (E-parameter), representing the total primary energy used, and
  
  
• The Resource parameter (R-parameter), representing the resource depletion involved .

The Environmental Calculator enables the designer to compare the environmental impacts in the whole life cycle of different design alternatives, and this can be done already in the concept phase, with very few data available and before the design has been finalised.

The database also contains:

• Data for the material content of the most common electronic components, to facilitate calculation of the total material content of the whole product, for example for Environmental Declaration purposes.
  
  
• A number of chemical lists, which can be applied for a chemicals evaluation. Please refer to 'Methods to measure and improve Environmental Performance with regards to Chemicals' for description of these possibilities.

Energy parameter (E-parameter)

The Energy parameter is an indicator of the draw on the global energy reserve, which with the present energy sources is declining.

It is also an indicator of the pollution resulting from an average global energy application; e.g. global warming gases, acidifying gases, gases contributing to nutrient enrichment, waste in the form of slag and in the form of radioactive wastes (from nuclear power plants).

The Energy parameter is an aggregation of the total life cycle energy measured as primary energy in MJ. This is the sum of the 'Net Calorific Value' (Material Energy) and the energy used for manufacturing (process energy). These values can be calculated by means of a LCA-tool, e.g. the Danish EDIP PC-Tool, which has been used for calculation of default values applied in Environmental Calculator I and II.

Resource parameter (R-parameter)

When a certain material is used for instance in a product, it means that the remaining virgin resources of this material has been diminished. Dependent on the scarcity of the resource, this is more or less serious.

The purpose of the Resource parameter is:

• to give an numeric indication of the total resource draw on virgin resources from the use of materials in a specific product
• to be able to compare products or different design solutions regarding resource draw

The Resource parameter is an indicator of the total non-energy draw on virgin resources. Energy resources are covered by the Energy parameter and are therefore excluded from the Resource parameter.

Calculation of the Resource parameter

The resource consumption (of e.g. copper) is divided by the known global reserves (of copper) per person. 1990 is used as reference year. See table 'World Reserves Life Index'.

Example:

The known global resources of copper in 1990 was: 321,000,000 ton.



The population in 1990 was: 5.29 billion persons



The known global resources per person in 1990 was therefore: 0,0607 ton/person or approx. 60 kg/person.



If 300 gram of copper is consumed in the product life cycle, copper contributes by:



R_Cu = 0,3 kg / 60 kg/person = 0,005 PR = 5 mPR (PR: person-reserves)

PR (person-reserves) are therefore also the unit for the R parameter for the product to which all the individual contributions are added.

The Resource and Energy scores used in this tool is one way to quantify the first two rows in the MECO system.

Example:

R = R_Al + R_Cu + R_Ag + R_Zn = 15.38 mPR

More information (and suggested literature) may be found in the LCA-section.