Importance of electricity mix in A3 for GWP and compliance with EPD format and its user manual
Electricity mixes may vary widely depending on the share of renewable vs. non-renewable energy sources used for production of electricity. Thus, the global warming potential - GWP - as result of greenhouse gas emissions from production and distribution of energy sources for the electricity used and for the electricity production itself, is depending on the choice of electricity mix.
In Norway there is an ongoing discussion on choice of electricity mix and thereby which “GWP-factor” to be used for electricity used in Norway. EPD-Norway – The Norwegian EPD Programme holder – wanted to find out how important the electricity used in the manufacturing stage is for the overall GWP for EPDs published. Østfold Research was engaged to perform a review of those EPDs published by EPD-Norway within the last year. A number of 50 EPDs were selected for review as they follow the European standard EN 15804:2012, and the new EPD template and its user manual required by EPD-Norway.
For 37 of 50 EPDs, data regarding electricity use in the manufacturing stage (A3) were available. Then, simulation of the GWP impact in A3 compared to GWP in A1- A3 have been performed using different electricity mix have on the total GWP for cradle to gate EPDs (A1-A3). The following GWP values were used:
- Low – future requirement from EPD-Norway: 0,024 kg CO2-eqv/kWh
- Medium – corresponds to Nordic Grid mix: 0,126 kg CO2-eqv/kWh
- High – as used by klimagassregnskap.no: 0,356 kg CO2-eqv/kWh
The simulations shows that the differences between the electricity model used in EPDs and the
suggested required (future) model (24 g CO2-eqv/kWh) are in the range of -4 to 1 percent. The use of the European electricity model in A3 is influencing the total GWP for A1-A3 less than 10 percent for the analysed EPDs for building products.
It is emphasized that this applies for those building products chosen in this study. Even though, for most building products manufactured in Norway, the manufacturing stage will be of minor importance compared to raw material production and especially, the user stage in the building or construction work.
In addition, the EPDs were reviewed regarding how methodological specifications given in the user manual have been interpreted and applied in the EPDs by addressing the following three questions:
- Are the Key environmental Indicator (KEI) “energy use” equal to the Resource use parameters describing “resources used as energy”?
- Are the Key environmental Indicator “recycled material in” equal to the Resource use parameter “secondary material”?
- Are the impact assessment parameter” ADPFossil fuels“ and the Resource use parameters “total nonrenewable primary resources with energy content” (TNRPE) correlated?
The declared KEI “Energy use” in Norwegian EPDs shall be equal to the declared numbers in the Resource use table given as the sum of the 4 resource use parameters renewable and non-renewable primary energy used as energy, and the renewable and non-renewable secondary fuels summarised for modules A1-A3. For 12 of 50 EPDs this is not the case.
The declared key environmental indicator “Recycled materials in” shall be declared as secondary materials (SM) in the resource table in the EPD as well. Not all product groups have this KEI as requirement. For those 14 EPDs this requirement apply for, none have declared “Secondary materials – SM” in the Resource use table, only as KEI.
For 12 of 45 EPDs the calculations and/or declaration of ADPFossil fuels and/or TNRPE are not correct. This can be explained by the following three causes. First, ADPFossil fuels for 3 EPDs are not declared at all. Then, ADPFossil fuels for 3 EPDs are declared higher than “total non-renewable primary energy resources” which are impossible. At last, for 6 EPDs the difference in TNRPE and ADPFossil fuels in percent of TNRPE are higher than the maximum limit 24 %.
In total, 27 of 50 EPDs have not applied the methodological specifications given in the user manual correctly. This review has not covered all aspect related to EPDs and compliance with the user manual. The review indicates that both LCA-practitioners and verifiers do not follow the user guide correctly. Even though this is related to common LCA and EPD knowledge, a revision of the user manual is recommended. EPD Norway will arrange training workshop for LCA practitioners and verifiers during the autumn 2014. It is recommended that the results from this review serve as basis for and input to how to apply the user manuals and programme instructions by EPD Norway when performing EPDs and doing verifications.