Environmental and cost assessment of diesel and hydrogen construction heavy-duty machinery using the life cycle assessment framework according to ISO 14040:2006

Abstract

In this era of sustainability, with high demand for clean energy systems, environmental protection, and economic development, this work aims to develop a science-based analysis that enables construction industry stakeholders to make informed decisions about power system choices based on environmental and cost considerations for construction machinery. The appropriate methodology for this work is the Life Cycle Assessment (LCA) and Life Cycle Costing (LCC), following the LCA framework as outlined in ISO 14040, related to the environmental and cost assessment of diesel and hydrogen excavators throughout their life cycle. This work uses SimaPro for the environmental LCA and a basic Excel model to calculate the LCC of each excavator. As for the results, green hydrogen fuel cell (FC) excavators significantly reduce environmental impacts compared to diesel, cutting climate change emissions by 75%, ozone-forming gases by 95%, and particulate pollution by 84%, while also lowering water and marine toxicity by around 94%. However, the FC systems require 52% more mineral resources and consume over five times more water. The Internal Combustion Engine (ICE) system is more cost-efficient at the acquisition stage. In contrast, FC systems benefit from lower operational costs due to reduced fuel consumption. This makes the FC system, under the optimal configuration, the most cost-effective choice in the long term. Hydrogen FC powertrains are expected to become cost-competitive with ICE systems as the cost of FC components decreases. Replacing diesel with hydrogen in machinery cuts fossil fuel use, promotes clean energy, and helps early adopters shape the low-carbon machinery market.