Comparative life cycle assessment of bio‐based insulation materials: Environmental and economic performances

Abstract

Insulation materials decrease the final energy consumption of buildings. In Germany, fossil and mineral insulations dominate the market despite numerous life cycle assessments (LCAs) showing that bio‐based insulations can offer environmental benefits. Evaluating the results of such LCAs is, however, complex due to a lack of comparability or costs considered. The objective of this study is comparing bio‐based insulations under equal conditions to identify the most environmentally friendly and cost‐efficient material. For this purpose, a comparative LCA and life cycle costing (LCC) were conducted from “cradle to grave” for four bio‐based and two nonrenewable insulations. The bio‐based insulation materials evaluated were wood fiber, hemp fiber, flax, and miscanthus. The nonrenewable insulations were expanded polystyrene (EPS) and stone wool. Key data for the LCA of the bio‐based insulations were obtained from preceding thermal conductivity measurements under ceteris paribus conditions. Eighteen environmental impact categories were assessed, and direct costs were cumulated along the life cycle. Results show that the most environmentally friendly bio‐based insulation materials were wood fiber and miscanthus. A hotspot analysis found that, for agriculturally sourced insulations, cultivation had the largest environmental impact, and for wood fiber insulation, it was manufacturing. The use phase (including installation) constituted a cost hotspot. The environmental impacts of end‐of‐life incineration were strongly influenced by the fossil components of the materials. Overall, bio‐based insulations were more environmentally friendly than EPS and stone wool in 11 impact categories. The LCC found EPS and miscanthus insulation to be most cost‐efficient, yet market integration of the latter is still limited. It can be concluded that miscanthus biomass is an environmentally and economically promising bio‐based insulation material. Comparability of the environmental performance of the bio‐based insulations was increased by applying the same system boundary and functional unit, the same impact assessment methodology, and the preceding ceteris paribus thermal conductivity measurements.

Nordic forest management towards climate change mitigation: time dynamic temperature change impacts of wood product systems including substitution effects

“…Meeting the same function among non-wood and woodbased products often requires varying mass amounts of each. For construction materials, this can result in substantially different mass replacement ratios (in the following also called replacement rates) (Cordier et al 2021), e.g., depending on the building type (Peñaloza et al 2019), or physical properties such as density or the thermal conductivity (Schulte et al 2021a). Given the variety of construction materials covered in this study, mass replacement rates according to multiple materials were adapted from Peñaloza et al (2016), Mehr et al (2018), and Piccardo and Gustavsson (2021) (Supplementary Material).…”

Enviro‐economic and feasibility analysis of industrial hemp value chain: A systematic literature review

“…Moreover, the economic viability of hemp fibers for various applications depends on the cost‐effective acquisition of fiber material, influenced by fluctuations in the fiber process (Seile et al., 2022). In fact, high cultivation (particularly N fertilization) and manufacturing costs has led to relative cost inefficiencies at the upstream level as compared to alternative bio‐based solutions such as miscanthus (Schulte et al., 2021). From the producer's perspective, high input costs may infer low relative profitability, regardless of the ultimate use.…”

Implications of large‐scale miscanthus cultivation in water protection areas: A Life Cycle Assessment with model coupling for improved policy support

“…In contrast, the replacement of the marginal electricity mix (Vandepaer et al, 2019) would reduce the reported avoided burden by over 50%, because the anticipated marginal electricity in 2030 relies to only 25% on fossil fuels. The potential substitution effects of other miscanthus products were not considered; however, available LCA studies for material use show benefits in the impact category climate change (Ntimugura et al, 2021; Patel et al, 2018; Schulte et al, 2021; Wagner et al, 2017). Nevertheless, assuming the absence of a substitution effect, the GHG balance for all scenarios would still be lower than the reference, because the carbon sequestration alone outweighs the additional emissions from iLUC.…”