LCA for decision support

Transcription

1 LCA for decision support Event 25th SETAC Europe Annual Meeting in Barcelona, Authors Fredy Dinkel, Thomas Kägi Carbotech AG, Basel Page 1 LCA for decision support 25th SETAC Europe Annual Meeting

2 Overview 1. About Carbotech 2. Another study on heating systems 3. Results from impact methods 4. Duty of practitioner 5. Different weighting in single score 6. Discussion 7. Conclusions 8. Session wrap up and panel discussion Page 2 LCA for decision support 25th SETAC Europe Annual Meeting

3 About Carbotech AG independent, neutral and objective since more than 25 years Environmental consulting Environmental consulting LCA System modelling: Fuzzy Sets, Monte Carlo, Environmental audits Cleaner Production Teaching and coaching LCA Pollutants/Contaminants Pollutants in buildings, like Asbestos, PCB/CP, organics, Diagnostics and project planning management Air pollution consultation (VOC, PM10 etc.) International cooperation Page 3 LCA for decision support 25th SETAC Europe Annual Meeting

4 About Carbotech AG independent, neutral and objective since more than 25 years 25. Anniversary of our first LCA Environmental consulting LCA System modelling: Fuzzy Sets, Monte Carlo, Environmental audits Cleaner Production Teaching and coaching LCA Page 4 LCA for decision support 25th SETAC Europe Annual Meeting

5 Another study on heating systems Main questions of the study The canton of Baselland wanted to know: 1. What are the environmental impacts of different heating systems? 2. Which heating systems have the lowest environmental impacts? Because they needed a decision base if one or more of these heating systems are worthy to be promoted. Page 5 LCA for decision support 25th SETAC Europe Annual Meeting

6 Another study on heating systems Considered heating systems Heating pump (HP) systems: Ice storage tank with HP Heating tiles with HP Air/Water HP SPF = 2.3 Brine/Water HP SPF = 3.7 Wood heating system: Wood pellets SPF of 4.9 is reported for ice storage if used also in summer for cooling. Fossil heating systems: Natural gas Oil SPF = seasonal performance factor of heat pump Page 6 LCA for decision support 25th SETAC Europe Annual Meeting

7 Results for European electricity Mix Ecological UBP 2006scarcity 06 ReCiPe, H,A IPCC 2007: GWP 100a Brine/Water Erdsonden-WP HP Erdsonden-WP Erdsonden-WP Air/Water L/W-WP HP L/W-WP L/W-WP Ice storage Isocal (SPF (JAZ 3.4) Isocal (JAZ 3.4) Isocal (JAZ 3.4) Ice storage Isocal (SPF (JAZ 2.3) Isocal (JAZ 2.3) Isocal (JAZ 2.3) Heat Atmova tiles (SPF (JAZ 3.4) Atmova (JAZ 3.4) Atmova (JAZ 3.4) Heat Atmova tiles (SPF (JAZ 2.3) Atmova (JAZ 2.3) Atmova (JAZ 2.3) Wood Pelletheizung pellets Pelletheizung Pelletheizung Oil, condensing Ölheizung Ölheizung Ölheizung Gas, condensing Gasheizung Gasheizung Gasheizung SPF = seasonal performance factor of heat pump Page 7 LCA for decision support 25th SETAC Europe Annual Meeting

8 Results for CH electricity Mix Ecological UBP 2006 scarcity 06 ReCiPe, H,A IPCC 2007: GWP 100a Brine/Water Erdsonden-WP HP Erdsonden-WP Erdsonden-WP Which Air/Water L/W-WP HP L/W-WP L/W-WP method Ice storage Isocal (SPF (JAZ 3.4) 3.4) Isocal (JAZ 3.4) Isocal (JAZ 3.4) should be Ice storage Isocal (SPF (JAZ 2.3) 2.3) Isocal (JAZ 2.3) Isocal (JAZ 2.3) used for Heat Atmova tiles (SPF (JAZ 3.4) 3.4) Atmova (JAZ 3.4) Atmova (JAZ 3.4) decision Heat Atmova tiles (SPF (JAZ 2.3) 2.3) Atmova (JAZ 2.3) Atmova (JAZ 2.3) support? Wood Pelletheizung pellets Pelletheizung Pelletheizung Oil, condensing Ölheizung Ölheizung Ölheizung Gas, condensing Gasheizung Gasheizung Gasheizung SPF = seasonal performance factor of heat pump Page 8 LCA for decision support 25th SETAC Europe Annual Meeting

9 Results depend on impact method Depending on the evaluation method and the electricity mix used for the heat pumps nearly all results could be given. Using the European electricity mix: method ecological scarcity natural gas has one of the best results. Global warming most systems are comparable or better than gas except oil. ReCiPe wood is the best option and all others do not show significantly different results taking into account the uncertainties. Page 9 LCA for decision support 25th SETAC Europe Annual Meeting

10 Duty of practitioner Communicating all the results which lead to different conclusions will not be helpful and can lead to confusion and to a loss of confidence in the method. According to ISO 14'044 single score methods shall not be used for comparisons disclosed to the public Let's have a look on Midpoint and Endpoint Indicators Page 10 LCA for decision support 25th SETAC Europe Annual Meeting

11 Duty of practitioner Communication on midpoint level only leaves the commissioner three options: 1.Equal weighting 2.Only looking at own chosen impacts 3.You are the expert, please, we paid for decision support! Page 11 LCA for decision support 25th SETAC Europe Annual Meeting

12 To simplify: selected impacts no result for decision support! What about the relevancies? => Normalization Page 12 LCA for decision support 25th SETAC Europe Annual Meeting

13 Normalization to find the relevant impacts Page 13 LCA for decision support 25th SETAC Europe Annual Meeting

14 Duty of practitioner Communication on midpoint level only Weighting with 0 is certainly wrong. Only looking at chosen impacts and therefore weighting all other impacts with 0 is much more subjective and arbitrary than a weighting according to socially accepted values. Fossil energy demand and climate change are very urgent environmental problems, but they are not the only ones. Does endpoint methods solve the problem? Page 14 LCA for decision support 25th SETAC Europe Annual Meeting

15 What about the endpoints Page 15 LCA for decision support 25th SETAC Europe Annual Meeting

16 What about the endpoints? Now it seems that a very efficient heat pump using Swiss electricity mix is best. But ReCiPe does not take into account nuclear resources. Swiss electricity mix has a high share of nuclear power. and again no clear winner Page 16 LCA for decision support 25th SETAC Europe Annual Meeting

17 Single score results The heat pump with CH Mix and very high SPF, seems to be best, but other questions appear: What is the appropriate electricity mix? CH mix or marginal electricity mix? What about wood pellets? Are they better than natural gas or not? Page 17 LCA for decision support 25th SETAC Europe Annual Meeting

18 Other single score results Taking into account radioactive waste can change the results Considering the uncertainties there are no significant differences between natural gas and wood Page 18 LCA for decision support 25th SETAC Europe Annual Meeting

19 Single score results The weighting of human toxicity can have a significant influence on the Results. Page 19 LCA for decision support 25th SETAC Europe Annual Meeting

20 Duty of practitioner Communication on single score level Single score indicators do not show the "truth". There is no true weighting methodand the weighting is debatable because not based on scientific models. So it is important that the weighting is transparent. Therefore, the practitioner should use More than one single score method Midpoint and Endpoint indicators for the interpretation It is the duty of the practitioner, being an expert, to analyse all the results and to choose the adequate method. Page 20 LCA for decision support 25th SETAC Europe Annual Meeting

21 Discussion Advantage of midpoints insight into the different impacts and can also take the local situation can be taken into account substantiate the conclusions Advantage of endpoints relevance of the different indicators Giving the damages Advantage of single score relevance of the different indicators Weighting based on consensus and not only on personal opinions In order to reach a sound decision, different single score methods together with the mid-and endpoint indicators should be used to conduct sensitivity analysis, which allows assessing the consequences on the LCIA results due to different value-choices of the weighting methods. Page 21 LCA for decision support 25th SETAC Europe Annual Meeting

22 Conclusions Single score indicators do not tell the truth but can be very helpful when it comes to decision support and to communicate an outcome. Even if only one single score is communicated it is crucial for the practitioner not to use only one single method for the conclusions that the values behind as well as the coverage is known and adequate to the goal and scope of the study. So we suggest completing the requirement in the ISO norm as follows: "If single score methods are used more than one single score method shall be used for comparative assertions disclosed to the public and the weighting has to be discussed and made transparent using mid- and endpoint indicators." Page 22 LCA for decision support 25th SETAC Europe Annual Meeting

23 Thankyou foryourattention! Page 23 LCA for decision support 25th SETAC Europe Annual Meeting

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