Life Cycle Assessment and Life Cycle Costing of the Worlds Longest - PowerPoint PPT Presentation

Life Cycle Assessment and Life Cycle Costing of the World’s Longest Pier: A case study on the environmental and economic benefits of stainless steel rebar 2014 [avniR] Conference, Life Cycle in Practice Lille, 5 th November 2014

Rationale Decision makers increasingly focus on environmental, economic and social considerations: - Carbon footprint: less impact in production is better - Costs of material chosen: cheaper is more economic - Conflict minerals: don´t use them / avoid them - Resource depletion: do not use scarce raw materials - … Do such indicators / aspects tell the full story to take a sustainable decision? 2

Progreso Pier, Mexico The oldest structure built with stainless steel reinforcement Progreso Pier built in 1941 Still in service Alternative Pier built in 1981 Collapsed in 1998 Background: Progreso Pier built in 1941 and still in service today 3

Comparative Life Cycle Assessment • What if the Progreso Pier had been built using other rebar? Aim: • Demonstrate the effectiveness of stainless steel rebar and other rebar in terms of: • Environmental performance • Economics (costs) • Assess entire life cycle of the pier: • Production • Use phase • End of life 4

Methodology Overview • Comparative assertion • Both designs serve the equivalent function • Stainless and carbon steel: same structural characteristics • Analysis period • 79 years – conservative approach • Provides estimate of past (1941 – 2013) and future (2013 – 2020) performance • System boundaries • Included: materials, transportation, maintenance, and end-of-life fates • Excluded: construction, use, and demolition as not expected to have a significant impact • Analysis methods • Life cycle assessment (LCA) conformant to ISO 14040 series • Life cycle costing (LCC) conformant to ISO 15686-5 Integrity of study assured through Critical Review

Comparison: Designs As-built Design (stainless steel rebar) Alternative Design (carbon steel rebar) • Materials • Materials • Concrete: 72,500 m3 • Concrete: 72,500 m 3 • Stainless steel rebar: 220 tons • Carbon steel rebar: 220 tons • Service life: 79 years • Service life: 79 years • Maintenance: to be determined • Maintenance: to be determined according to maintenance schedule according to maintenance schedule (see following slide) (see following slide) Study compares same pier design with different materials. Conservative approach chosen as concrete thickness for SS rebar can be reduced.

Maintenance: The Key Difference 20% Repair Initial Construction 15% Repair 10% Repair As-built Design (stainless steel rebar) 0 44 59 74 79 0 10 25 40 50 60 75 79 Alternative Design (carbon steel rebar) 10% Repair 10% Repair 15% Repair 15% Repair Initial Reconstruction Construction 20% Repair * Maintenance schedule as defined by: US Navy predicted maintenance schedule. US Navy, Final report for the floating double-deck pier, TR-NAVFAC ESC-CI-1223, September 2012. Maintenance schedule was developed according to globally accepted US Navy predicted maintenance schedule (2012)

Comparison: Materials Stainless Steel Rebar Carbon Steel Rebar Price (2013$): Price (2013$): $2.99/kg $0.45/kg 10 150 10 150 GWP [kg CO 2 -eq/kg] GWP [kg CO 2 -eq/kg] 7,40 PED [MJ/kg] PED [MJ/kg] 106 100 100 5 5 50 50 2,30 25,8 0 0 0 0 GWP – Global Warming Potential [kg CO 2 -eq/kg] PED – Primary Energy Demand [MJ/kg] The cost and carbon footprint of the rebar materials only look into first stage of the life cycle, but do not tell the full story in view of material use & maintenance

LCA Results: Breakdown of material contributions – initial construction 50 Global Warming Potential [million kg CO 2 -eq] 45 Production 40 35 Rebar 30 End-of-Life Use 25 20 Concrete 15 10 Concrete dominates the 5 carbon footprint of 0 the materials As-Built Design Alternative Design 9 As-built design has 2% bigger carbon footprint than alternative design Concrete dominates the carbon footprint of the materials

LCA Results Total environmental impacts over 79-year analysis period Impact relative to As-built Design 200% Production 180% 160% 140% End-of-Life Use 120% 100% As-built Design 80% Alternative Design 60% AP = Acidification Potential 40% EP = Eutrophication Potential GWP = Global Warming Potential, i.e. Carbon Footprint 20% ODP = Ozone Depletion Potential POCP = Photochemical Ozone Creation Potential, i.e. Smog Formation Potential 0% AP EP GWP ODP POCP As-built design has 71% smaller carbon footprint than alternative design 10

Life Cycle Costing Results Discount Rate of 0.01% (recommended by SETAC * ) Net Present Cost [thousand 1941 USD] 1000 900 Alternative Design As-built Design A credit is 800 applied to Net Present Cost (NPC) [thousand 1941$] 700 account for remaining 600 structural service life. 500 400 300 200 *Swarr et al. Environmental life cycle costing: a code of practice. Society of Environmental Toxicology and 100 Chemistry. 2011. 0 1940 1950 1960 1970 1980 1990 2000 2010 2020 Year Cost of the as-built design ($520k) is nearly 30% less than that of the alternative design ($730k).

Life Cycle Costing: LCC is sensitive to discount rate • EU: “Use of a low ( 3% or less ) or even a zero rate is recommended 5% when LCC is used to assess the economic merits of alternative sustainability options.”* 4% • US Navy reports 0%, 1%, and 2.3% 3% • US Circular A94 currently uses 1.1% based on the 30-year bond • SETAC: 0.01% discount rate for long-term investments (over 30 years) 2% 1% * European Commission. Life Cycle Costing (LCC) as a contribution to sustainable construction: a common methodology. 2007. 0% Discount rates between 0% and 1% are most commonly used by regulators and scientists whereas rates between 3% and 5% are seen as overly conservative. 12

Life Cycle Costing: Sensitivity Analysis Discount Rate: 0.01% Discount Rate: 1.0% Discount Rate: 3.0% Discount Rate: 4.0% The Sensitivity analysis shows that up to a discount rate of 4%, the as-built design is more economic when looking also into the use phase

Conclusions Environmental benefits and long term economic savings Environmental benefits • Use of stainless steel provided long service life of the Progreso Pier • Increased service life provides environmental benefits over entire life cycle Economic benefits of Stainless Steel Rebar • Significant economic benefit of using stainless steel rebar • Even at overly conservative discount rates (4%) there is still an economic benefit Even with overly conservative approaches and assumptions used for the LCA, the use of SS rebar creates significant environmental and economic benefits 14

Social considerations Some thoughts on inclusion of social considerations • There are social impacts but also benefits created • Employment in remote areas, wages • Social engagement of companies in communities, creation of infrastructure • We have to be aware of target conflicts • Long life time of products and less maintenance vs. employment • Complex value chains – challenging to track and ensure information flow • N° of stakeholders between raw material producers and end users • Concern of oversimplifying things • Complex systems and interaction between environment, economics & social aspects • There is already a lot done in the mining and metals industry • ICMM activities on responsible sourcing, conflict minerals, … 15

Social considerations Can and shall LCA address all dimensions of sustainability? • LCAs show an added value for certain environmental and economic considerations • LCA can also help companies to benchmark their performance on certain technical aspects and to demonstrate their performance • When applying full life cycle thinking, LCA and LCC are useful to take adequate decisions • We should avoid overlapping with other activities that better fit for the purpose • Risk Assessments (environmental, human health) • CSR activities by companies and sectors • Initiatives from industry (e.g. ICMM) 16

Full peer reviewed LCA report & more information: www.nickelinstitute.org mmistry@nickelinstitute.org