Life Cycle Analysis for Transport Modes

Environmental impact assessment exercises carried out to support decision making in the transport sector do not consider the full life cycle energy and CO2 impacts of transport modes and focus on the tail pipe impacts only. It is, however, necessary that a holistic approach be adopted while analysing the impacts of the sector. Different transport modes involve varying degrees of construction and maintenance activities - while some modes may be highly material and energy intensive, others may be comparably less intensive. Material and energy consumption at various stages of a transport project, i.e., construction, operations, and maintenance, need to be examined in order to fully understand their impacts on the environment. Life cycle analyses are typically used to assess such full-life impacts of various products, systems, projects, etc.

Application of Life Cycle Analysis (LCA) to the transport sector becomes important as transport impacts are not limited to tail pipe only. Full life cycle impacts of transport need to be accounted and recognized while taking policy decisions related to 'greening' of the sector.

In order to understand the full life cycle impacts of different modes of transport in India, the National Transport Development Policy Committee (NTDPC) constituted by the Government of India commissioned a study to TERI to conduct a life cycle analysis of various modes of transport. The aim of the study was to establish a robust India-specific methodology to estimate the life cycle impacts of transport modes in terms of energy consumption and CO2 emissions, and to measure these impacts for typical transport projects. The selected transport projects for this study included three urban transportation systems, i.e., urban road, Bus Rapid Transit System (BRTS), and Metro Rail Transit System (MRTS), and two long-distance modes, i.e., National Highway (NH) and long-distance passenger railway.

TERI's LCA Methodology

As stated earlier, the twin objectives of this study were to formulate a robust LCA methodology to compare different modes of transport on the basis of their life cycle impacts, and to use this methodology to estimate the per unit energy consumption and carbon emission values for the selected modes of transport in India at different stages of their life cycle. This was urgently required as no comprehensive India-specific LCA studies had been conducted for the transport sector, other than a study which TERI had conducted for the Asian Development Bank (ADB) in 2010 which was specific to the road sector only. International studies could only serve as a guide and could not be adopted as they were, and thus, the aim of this study was to establish a comprehensive India-specific framework for transport sector LCA.

The methodology so established by TERI for life cycle assessment of transport modes is a 'cradle to grave' approach comprising identification and quantification of material and energy consumption and CO2 emissions at all stages of the entire life cycle of transport projects. The LCA framework drawn up by TERI is in line with the ISO 14000 framework for carrying out LCA studies. The scope of such an analysis encompasses direct energy and material consumption during construction, operation, and maintenance, as well as indirect consumption through manufacture of rolling stock and production of fuels (largely non-renewable fossil fuels).

The selected modes of transport for this study included three urban transportation systems - urban road, Bus Rapid Transit System (BRTS), and Metro Rail Transit System (MRTS) - and two long-distance modes, i.e., National Highway (NH) and long-distance inter-city passenger railway.

The life stages studied were in consonance with typical LCA methodologies for the transport sector. TERI considered the key construction, operation, and maintenance sub-stages, which included the following:

  • Consumption of materials for construction
  • Transportation of construction materials, waste, and labour to and from construction site
  • On-site energy usage
  • Consumption of materials for annual and periodic maintenance
  • Material and energy consumption for manufacture and maintenance of rolling stock
  • Direct energy consumption for rolling stock operations

Outcomes and Achievements

The application of TERI's methodology indicates that LCA is doable for transport projects. This is indeed the biggest contribution of the study, which has helped shift focus from direct operational emissions to the life stages of transport projects that are usually ignored while assessing environmental impacts.

The study has proved useful in two ways. The results show that an understanding of the overall life cycle impacts of transport modes can help compare and select the most energy efficient and environment friendly modes by shifting towards infrastructure that is least energy- and carbon intensive throughout its lifetime. Additionally, LCA can also be used to suggest intra-modal improvements as it helps understand the share of various components that contribute to energy consumption and emissions, hence helping in identifying appropriate mitigation measures.

The findings also indicate that if the life of projects is enhanced through regular maintenance, then the energy and CO2 impacts due to re-construction can be reduced or deferred, especially in the case of road-based projects that tend to have shorter lifespans. Thus, the maintenance of constructed assets should be given due importance as it will help reduce both monetary and environmental costs. Furthermore, an area of research emerging as significant is alternative materials and fuels in order to identify energy efficient and low-carbon substitutes to conventional inputs.

Some areas where energy reduction can be achieved during the life of a transportation system:

  • Reducing energy and CO2 intensity of the conventional materials used
  • Using alternative materials that are comparatively less energy and CO2 intensive
  • Using locally available materials
  • Using energy-efficient processes and machinery during construction and maintenance
  • Optimizing resource utilization during construction and maintenance, especially for transportation of materials (using locally available materials, reducing idling, using rail for bulk transport of materials, etc.)
  • Promoting inter-modal shift (towards more energy-efficient modes)
  • Improving efficiency of rolling stock
  • Reducing energy and material intensity during manufacturing and maintenance of rolling stock

Recommendations

Further work is necessary to fine-tune the methodology and adapt it for use on an on-going basis for taking informed investment decisions. The successful use of the methodology will depend on data availability, which is a challenge in India. Hence, a database for LCA for the transport sector should be created with encouragement and support from the government.

It should be noted that the LCA methodologies, approaches, and results for all countries vary on account of several reasons, such as differences in construction technologies, use of materials, embodied energy and carbon factors, fuel emission factors, levels of efficiency, etc. Ideally, the results should be compared with LCA exercises for the same country, with the LCA methodology and system boundary being the same for the compared projects. It is, hence, not appropriate to compare the LCA results derived for other countries with the Indian results derived through this study. Due to the absence of any other such study for India, TERI has not attempted to compare the results of this research with any other study. TERI's work is a pioneering effort and should be used as a model and enhanced further to achieve sufficient 'greening' of the transport sector in India.

Sponsor: National Transport Development Policy Committee (NTDPC), Government of India
Duration: 6 months
Key Stakeholder / Beneficiaries: Policy-makers and planners, transport researchers
Objectives
  • Establish a robust LCA methodology to compare different modes of transport on the basis of their life cycle impacts in terms of energy consumption and CO2 emissions
  • Use the LCA methodology to estimate the life cycle energy consumption and CO2 emission values for five selected modes of transport

Table 1 Selected Transport Projects for Which Data Was Collected to Estimate Life Cycle Energy Consumption and CO2 Emissions

Mode Construction Projects Maintenance Projects
National Highway Four laning of Rohtak–Bawal NH (NH-71) Maintenance of Delhi–Agra NH
Long-distance rail Construction of Rewari–Rohtak new line Maintenance of Delhi–Bathinda line
Metro rail Construction of Delhi Metro Maintenance of Delhi Metro
BRTS Construction of Ahmedabad BRTS Maintenance of Ahmedabad BRTS
City road Construction of a typical road in Delhi Maintenance of a typical road in Delhi
Figure 1 Life Cycle Energy Consumption per Passenger Kilometre (PKM): Ahmedabad BRTS and Delhi Metro Rail (Phase I and II) Projects
Figure 2 Life Cycle CO2 Emissions per Passenger Kilometre (PKM): Ahmedabad BRTS and Delhi Metro Rail (Phase I and II) Projects
Figure 3 Embodied Energy per Kilometre (km): Results for Construction and Maintenance Stages
Figure 4 Embodied CO2 Emissions per Kilometre (km): Results for Construction and Maintenance Stages
Posted on: 19 December 2013  |   Project status: Completed