Environmental Priority Strategies (EPS)
EPS is a systematic approach to choose between design options in product and process development. Its basic idea is to make a list of environmental damage costs available to the designer in the same way as ordinary costs are available for materials, processes, and parts. The designer may then calculate the total costs over the product’s life cycle and compare optional designs.
The EPS system, (Environmental Priority Strategies in product design) was developed to meet the requirements of an everyday product development process where the environmental concern is just one among several others. The development of the EPS system started in 1989 on request from Volvo and as a co-operation between IVL Swedish Environmental Research Institute, Volvo and the Swedish Federation of Industries (within the competence center Swedish Life Cycle Center (former CPM).
Since then, it has been modified several times during projects, which have involved several companies, like in the Swedish Product Ecology Project and in the Nordic NEP project.
About the EPS impact assessment method
EPS includes an impact assessment (characterisation and weighting) method for emissions and use of natural resources, which can be applied in any Life Cycle Assessment (LCA).
The results of the EPS impact assessment method are damage costs for emissions and use of natural resources initially expressed as ELU (Environmental Load Units). One ELU represents an externality corresponding to one Euro environmental damage cost. In later versions conventional currency, like € or $ is used.
Versions
Several versions of EPS have been published. The versions 1996, 2000, 2015 and 2020 use monetary damage costs. The present version was released 2020 and has been developed within a project coordinated by Swedish Life Cycle Center
External link, opens in new window..
EPS 2015 were made in two versions:
- 2015dx - excluding climate impacts from secondary particles
- 2015d - including climate impacts from secondary particles
The reason for developing two 2015 versions was the uncertain but important valuations of near-term climate forcers (NTCF) such as Nitrogen oxides (NOx) and Sulphur dioxide (SO2) emissions.
In the EPS 2020 the impact of NTCF was considered established knowledge, and only one default version was published.
Excluding climate impacts from secondary particles (2015dx)
In the IPCC Assessment Report (AR 5), emissions effecting global warming are reported as direct or indirect. Direct effects could be derived from greenhouse gases such as carbon dioxide (CO2) and methane (CH4), while indirect effects come from for example NOx and SO2 emissions. The indirect effects are caused by atmospheric reactions such as formation of ozone and secondary particles. Such reactions may decrease or increase global warming.
The present knowledge about the quantitative extent of indirect effects is uncertain. One reason for this is the short lifetime of emissions involved in secondary atmospheric reactions and consequently a strong dependency of local conditions. Another reason is that there are relatively few studies made, which include secondary effects, in particular from secondary particles. There is however a reasonably good consensus that NOx has a negative effect on radiative forcing.
In version 2015dx, the climate impacts from secondary particles are excluded. This implies overall positive damage costs for e.g. NOx and SO2 (i.e. increasing the environmental damage costs).
Including climate impacts from secondary particles (2015d)
In the version 2015d, the climate impacts from secondary atmospheric reactions are included. This implies overall negative damage costs for e.g. NOx and SO2 (i.e. reducing the environmental damage costs).
In cases when there are low emissions of fossil CO2 (e.g. with large share of bio fuels and significant amounts of NOx), the 2015d version might end up with net negative impact assessment results for the analysed system.
The UNEP-SETAC Life Cycle Initiative (2012-2017) was launched as a flagship project to provide global guidance and build consensus on environmental LCIA indicators (see http://www.lifecycleinitiative.org External link, opens in new window.).
Their recommendation 2017 was that “near-term climate forcers (NOx, SO2, black carbon, etc.) can be used in sensitivity analyses if their contribution is expected to be important, but not to be included in the climate change impact score because of very high uncertainties and important regional variability. This may change in the future as models improve”. (Levasseur 2016)*
It was therefore recommended that the version including these secondary impacts (2015d) is used with care (e.g. in sensitivity analyses) and by LCA practitioners and experts understanding the underlying concept.
* Levasseur A, CIRAIG - École Polytechnique de Montréal, Canada, personal communication 2016.
Including climate impacts from secondary particles (2020d)
In the version 2020d, the climate impacts from secondary atmospheric reactions are included. This implies overall negative damage costs for e.g. NOx and SO2 (i.e. reducing the environmental damage costs).
In cases when there are low emissions of fossil CO2 (e.g. with a large share of bio-fuels and significant amounts of NOx), the 2020d version might end up with net negative impact assessment results for the analysed system.
Description and downloading EPS
The 2015 versions are still available for downloading as they are documented in Excel format compatible with some software LCI data formats and containing background material which can be downloaded below. For each version there is one excel file presenting the damage costs for emissions and use of natural resources and one excel file showing the calculations made for deriving damage costs via characterisation and weighting factors.
The EPS 2020 version is available as a report from the Swedish life cycle center (2020:6) (https://www.lifecyclecenter.se/wp-content/uploads/2020_06_EPS-weighting-factors-version-2020d-2.pdf External link, opens in new window.). Background material is available in a book (Steen, B. 2019. Monetary Valuation of Environmental Impacts. Models and Data. CRC Press, Taylor & Francis Group, Boca Raton, FL USA)
Background EPS documentation
A more detailed description of the EPS concept can be found in the reports below.
- A Systematic Approach to Environmental Priority Strategies in Product Development (EPS) Version 2000 – General System Characteristics: Steen Bengt, CPM report 1999:4 External link, opens in new window..
- A Systematic Approach to Environmental Priority Strategies in Product Development (EPS) Version 2000 – Models and Data of the Default Method: Steen Bengt, CPM report 1999:5. External link, opens in new window.
- Calculation of Monetary Values of Environmental Impacts from Emissions and Resource Use - The Case of Using the EPS 2015d Impact Assessment Method: Steen Bengt, Journal of Sustainable Development; Vol. 9, No. 6; 2016 External link, opens in new window..
- Monetary Valuation of Environmental Impacts | Models and Data | External link, opens in new window.