Abstract
Purpose
This paper explores the potential to simplify the life cycle assessment (LCA) process for a hydropower (HP) system, without significantly compromising the accurate representation of environmental burdens. Taking five HP case studies, two questions were addressed: (i) Does a 1 % materiality threshold capture at least 95 % of the key environmental burdens from cradle-to-operation? (ii) What is the effect of applying a materiality threshold based on the global warming potential (GWP) indicator for capturing other environmental impacts?
Methods
A comprehensively detailed inventory database was developed for five modern small- and micro-HP case studies (50–650 kW), representing run-of-river and water supply infrastructure installations from the UK and Ireland. Following ISO 14040 standards, the environmental burdens were quantified for these HP projects. Normalised results were compared against a natural gas combined cycle power plant (NG-CCP) reference system for marginal grid electricity generation.
Results and discussion
The adoption of a 1 % materiality threshold as advised by some guidelines led to cumulative omissions of up to 7.5 % of the total project burdens for some HP installations, contravening the 95 % inclusion target. The number of project components differed between the two types of HP projects and target exceedances were more likely for projects with more components. Using a lower materiality threshold of 0.2 or 0.5 % ensured that the 95 % target was achieved for all HP projects. Considering GWP as an indicator burden for assessing materiality thresholds led to significant omissions for other environmental burdens, e.g. abiotic resource depletion potential (ARDP). Omitting a number of small components with low-carbon contributions (e.g. copper wiring) led to a 19 % underestimation for contributors to the resource-based (GWP) impact categories.
Conclusions
A simplified methodology may not capture all environmental burdens for a hydropower system or fossil fuel-based power plant. Basing a 1 % materiality threshold on contribution to a single burden, such as GWP, can lead to omissions of significant contributory components for that burden, and larger omissions for other burdens. ARDP is a particularly important impact category for renewable energy systems and appears to be particularly sensitive to materiality thresholds. It is important that practitioners take care with materiality thresholds when evaluating the environmental performance of all types of renewable energy systems through LCA. Including a materiality threshold to draw practicable system boundaries is necessary; however, reducing the threshold contribution to 0.5 % would be more likely to ensure that at least 95 % of environmental burdens are accounted for.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
Explore related subjects
Discover the latest articles and news from researchers in related subjects, suggested using machine learning.References
axpo Kleinwasserkraft AG (2014) Environmental Product Declaration: Au-Schönenberg small-scale hydro power plant. In: Axpo Kleinwasserkraft, AG (ed.). Baden
Bódis K, Monforti F, Szabó S (2014) Could Europe have more mini hydro sites? A suitability analysis based on continentally harmonized geographical and hydrological data. Renew Sust Energ Rev 37:794–808
Bonton A, Bouchard C, Barbeau B, Jedrzejak S (2012) Comparative life cycle assessment of water treatment plants. Desalination 284:42–54
BSI (2011) PAS 2050:2011 Specification for the assessment of the life cycle greenhouse gas emissions of goods and services. British Standards Institution
Chomkhamsri K, Pelletier N (2011) Analysis of existing environmental footprint methodologies for products and organizations: recommendations, rationale, and alignment. In: Unit HSA (ed). Institute of Environment and Sustainability, Ispra, Italy
CML (2010) Characterisation factors database available online from Institute of Environmental Sciences (CML). Universiteit Leiden, Leiden
Curran MA (2013) Life cycle assessment: a review of the methodology and its application to sustainability. Curr Opin Chem Eng 2:273–277
D’Souza, N, Gbegbaje-Das, E, Shonfield P (2011) Life cycle assessment of electricity production from a V112 turbine wind plant. In: Nwe P (ed). Vestas Wind Systems A/S, Denmark
DECC (2012) Electricity generation costs. Department of Energy & Climate Change
Defra (2013) 2013 GHG conversion factors for company reporting: methodology paper for emission factors. PB 13988 ed.: DEFRA, UK
Defra (2014) Greenhouse gas conversion factor repository. DEFRA, UK
Dŵr Cymru Welsh Water (2013) RE: Strata Florida Water Treatment Works—Hydro Scheme. Type to Fairman, MPA
Ecoinvent (2014) Ecoinvent database version 3. In: Simapro, AV (ed)
Ellergreen Hydro (2014) 50 kW Hydropower scheme (anonymous)
Envirodec (2015) Product group classification: un cpc 171 and 173. Electricity, steam and hot/cold water generation and distribution 2007:08. Envirodec
Fleming N (2013) RE: Vartry Reservoir and Water Treatment Works—Vartry Hydro Scheme
Flury K, Frischknecht R (2012) Life cycle inventories of hydroelectric power generation. Öko-Institute e.V
Gagnon L, van de Vate JF (1997) Greenhouse gas emissions from hydropower: the state of research in 1996. Energy Policy 25:7–13
Gallagher J, Styles D, McNabola A, Williams AP (2015a) Current and future environmental balance of small-scale run-of-river hydropower. Environ Sci Technol 49(10):6344–6351
Gallagher J, Styles D, McNabola A, Williams AP (2015b) Life cycle environmental balance and greenhouse gas mitigation potential of micro-hydropower energy recovery in the water industry. J Clean Prod 99:152–159
GHG Protocol (2011) Quantifying the greenhouse gas emissions of products: PAS 2050 & the GHG Protocol Standard. A short guide to their purpose, similarities and differences. GHG Protocol
Guezuraga B, Zauner R, Pölz W (2012) Life cycle assessment of two different 2 MW class wind turbines. Renew Energy 37:37–44
Hondo H (2005) Life cycle GHG emission analysis of power generation systems: Japanese case. Energy 30:2042–2056
IEA (2014) World Energy Outlook 2014—executive summary. OECD/IEA, Paris
ISO (2006) ISO 14040: environmental management—life cycle assessment—principles and framework. ISO, Geneva
Kenny T, Gray NF (2009) Comparative performance of six carbon footprint models for use in Ireland. Environ Impact Assess Rev 29:1–6
Lee C-K, Lee J-Y, Choi Y-H, Lee K-M (2015) Application of the integrated ecodesign method using the GHG emission as a single indicator and its GHG recyclability. J Clean Prod. doi:10.1016/j.jclepro.2014.10.081
Monahan J, Powell JC (2011) An embodied carbon and energy analysis of modern methods of construction in housing: a case study using a lifecycle assessment framework. Energy and Buildings 43:179–188
National Trust Wales (2014a) 100 kW Hafod y Porth Hydro
National Trust Wales (2014b) 650 kW Hafod y Llan Hydro
Pascale A, Urmee T, Moore A (2011) Life cycle assessment of a community hydroelectric power system in rural Thailand. Renew Energy 36:2799–2808
Pehnt M (2006) Dynamic life cycle assessment (LCA) of renewable energy technologies. Renew Energy 31:55–71
Raadal HL, Gagnon L, Modahl IS, Hanssen OJ (2011) Life cycle greenhouse gas (GHG) emissions from the generation of wind and hydro power. Renew Sustain Energy Rev 15:3417–3422
REN21 (2014) Renewables 2014 Global Status Report. ISBN 978-3-9815934-2-6 ed. Paris
Rule BM, Worth ZJ, Boyle CA (2009) Comparison of life cycle carbon dioxide emissions and embodied energy in four renewable electricity generation technologies in New Zealand. Environ Sci Technol 43:6406–6413
Suwanit W, Gheewala S (2011) Life cycle assessment of mini-hydropower plants in Thailand. Int J Life Cycle Assess 16:849–858
Turner M, Kraus J (2011) Emerging guidelines for product-level carbon footprints: a comparison of the proposed GHG product accounting and reporting standard to PAS 2050. A Source 44 Technical White Paper. Source 44
Varun I, Bhat K, Prakash R (2008) Life cycle analysis of run-of river small hydro power plants in India. Open Renew Energy J 1:11–16
Acknowledgments
This paper was carried out as part of the Hydro-BPT project (www.hydro-bpt.eu), which is part funded by the European Regional Development Fund (ERDF) through the Ireland–Wales Programme 2007–2013 (INTERREG 4A). The authors would also like to thank the organisations who supplied data: Dŵr Cymru Welsh Water; Dublin City Council; National Trust Wales; Ellergreen Ltd.
Author information
Authors and Affiliations
Corresponding author
Additional information
Responsible editor: Roland Hischier
Rights and permissions
About this article
Cite this article
Gallagher, J., Styles, D., McNabola, A. et al. Inventory compilation for renewable energy systems: the pitfalls of materiality thresholds and priority impact categories using hydropower case studies. Int J Life Cycle Assess 20, 1701–1707 (2015). https://doi.org/10.1007/s11367-015-0976-6
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11367-015-0976-6