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JEC Well-to-wheels analyses (WTW)

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The well-to-wheels analyses by JEC pursues the objectives of estimating:

  • greenhouse gas emissions,

  • energy efficiency, and

  • industrial costs

...of all automotive fuels and power-trains options significant for Europe after 2010.

The study evolves by periodic updates incorporating process improvements reported by the relevant stakeholders, e.g. vehicle manufacturers, Original Equipment Manufacturers (OEMs), fuel, refining, biofuels and power producers as well as regulators.

Outcomes are intended to serve as a sound and broadly accepted scientific reference.

The WTW approach differs from a Life Cycle Analysis (LCA), as it does not consider energy and emissions involved in building facilities and the vehicles, or end of life aspects.

Therefore, the WTW analysis by JEC focuses on:
  • fuel production (Well-to-Tank - WTT)
  • vehicle use (Tank-to-Wheel – TTW)

...that is the major contributors to lifetime energy use and GHG emissions.

Nonetheless, the WTW approach

  • Makes no estimates of overall “costs to society” such as health, social or other speculative cost areas.
  • Assumes all plants and vehicles to meet current and incoming future regulations, when considering regulated pollutants.


Sources - Crude oil, Coal, Compressed Natural Gas (CNG), Biomass, Wind, Nuclear.

Fuels - Conventional Gasoline/Diesel/Naphtha, Synthetic Diesel (F-T), CNG, Hydrogen (compressed / liquid), Methanol, DME, Ethanol, FAME.


Power-trains - Spark ignition (Gasoline, CNG, Ethanol, Hydrogen), Compression ignition (Diesel, DME, FAME), Fuel Cell and Hybrids (SI, CI, FC), Hybrid Fuel Cell with on-board reformer.


The methodology and data-set developed to provide a basis for the evaluation of pathways needs updating keeping the pace with innovative technologies.

The specific pathway is critical: a shift to renewable/low fossil carbon routes may offer a significant GHG reduction potential but generally requires more energy. 

A shift to renewable/low carbon sources is currently expensive. GHG emission reductions always entail costs but high cost does not always result in large GHG reductions

No single fuel pathway offers a short term route to high volumes of “low carbon” fuel

  • Contributions from a number of technologies/routes will be needed
  • A wider variety of fuels may be expected in the market
  • Blends with conventional fuels and niche applications should be considered if they can produce significant GHG reductions at reasonable cost.

Large scale production of synthetic fuels or hydrogen from coal or gas offers the potential for GHG emissions reduction via CO2 capture and storage (CCS) and this merits further study.

Advanced biofuels and hydrogen have a higher potential for substituting fossil fuels than conventional biofuels.

  • High costs and the complexities around material collection, plant size, efficiency and costs are likely to be major hurdles for the large scale development of these processes.

Transport applications may not maximize the GHG reduction potential of renewable energies

  • Optimum use of renewable energy sources such as biomass and wind requires consideration of the overall energy demand including stationary applications.

Results to be further evaluated in the context of volume potential, feasibility, practicability, costs and customer acceptance of the pathways investigated.




The JEC well-to wheel analysis provides a technology and policy-neutral methodology to grasp the implications and issues at stake with each technological pathway by considering performance with regard to both greenhouse gas emissions reduction and energy efficiency enhancement while providing key hints on cost viability of different options.