Other vehicle technologies are less sustainable

1. Parallel hybrids

Parallel hybrids, such as the Toyota Prius, are powered simultaneously by an Internal Combustion Engine and an electric motor, which slightly reduces their fuel consumption.
 
Several upcoming parallel hybrids models are plug-in, which means that some of their power will come from the electric network and stored in batteries. This will further reduce their fuel consumption. However, this technology is more complex and less energy-efficient than the Extended Range Electric Vehicle (EREV) technology.

Futhermore, Parallel Hybrids cannot operate at full power in electric mode : unlike EREVs, the engine is needed for normal car operation. Hence parallel hybrids are only zero emission vehicles at low power, which is a significant drawback in urban environments.

Therefore, we only mildly support parallel hybrids as a transition towards BEVs, EREVs, and later FCVs.

2. Hydrogen powered ICVs

Another possible use for hydrogen is the replacement of petrol as fuel for Internal Combustion Vehicles (ICVs). Since hydrogen combustion only produces water, these vehicles can contribute to reducing urban pollution.

However, the production, compression and transport of hydrogen and its transfer into the vehicle require a lot of energy: Well-to-Wheel, the energy efficiency of hydrogen ICVs is about half of petrol ones. Hence, we do not support hydrogen ICV technology.

3. Biofuels powered cars

Biofuels are fuels produced from a renewable biological resource, such as crops and other form of biomass.

However, using biofuels in cars is far from being the cleanest option. Indeed, the table below shows the reduction in CO2 emission and urban pollution generated by cars, as well as in cars oil consumption, under four scenarios:

1. Replacing all Internal Combustion Vehicles (ICVs) by a mix of 25% large Battery Electric Vehicles (BEVs), 25% ultra-small BEVs and 50% Extended Range Electric Vehicles (EREVs).
2. Reducing the average ICV consumption by 25%, i.e. lowering the car’s average CO2 emission from about 160 g CO2/km to 120 g CO2/km (as per EC Regulation No 443/2009).
3. Imposing 10% biofuels in transport (as per Directive 2009/28/EC).
4. Combining scenarios 2 and 3.

*    With European 2006 average electricity mix (443 gCO2/kWh – source: JRC).
** Assumes that biofuels save 50% greenhouse gas emissions and 100% oil consumption.

This table shows that replacing all ICVs by EVs (50% BEVs & 50% EREVs) would bring about double the combined benefits of reducing average ICVs CO2 emissions to 12Og CO2/km and using 10% biofuels in ICVs.

Hence, for lightweight road vehicles, promoting EVs is a much more effective measure than imposing biofuels and CO2 reductions onto ICVs.
All efforts should be directed towards fast EV generalisation.

On the other hand, biomass and biofuels are an effective option in some other applications, such as:

• Using biomass directly as a fuel for electricity production. This would save the expense and efficient loss of converting biomass to biofuels. Capturing the CO2 emitted by biomass fuelled power plants and storing it underground (CCS) would be a way of producing negative CO2 emissions.
   
• Using biofuel for vehicles that cannot be powered by electricity or hydrogen fuel cells, such as airplanes.

While biofuels can be considered as sustainable fuels since they capture their energy from the sun (through photosynthesis) and are renewable, they have limitations, and indiscriminate production can present serious drawbacks:

• Growing biofuels crops can only be done to the detriment of other land uses - such as croplands, which may be detrimental to food production, or wild land, which may be detrimental to biodiversity.
   
• Biomass conversion to biofuel consumes energy (20 to 70% depending on the crop type). Burning biomass directly into power plants to provide electricity for BEVs would be a more effective way of reducing global CO2 emissions.
   
• Crops are very inefficient at capturing sun energy - about 10 times less than current photovoltaic cells. However, photovoltaic panels are currently much more expensive and, with today's technologies, are not yet fully sustainable for large scale applications in temperate weather, since their production and installation consumes a large fraction of potential CO2 and energy savings.
   
• If all croplands were used for biomass production, only a fraction of the world's current energy needs would be covered. Therefore, available biomass is rather precious and should only be used in applications where it can bring more benefits than other technologies.

4. Compressed air vehicles

Compress air vehicles are powered by compressed air stored in a high pressure tank.
They produce no exhaust gases and may therefore appear as a clean technology.
Unfortunately, simple calculations demonstrate that:

• Well-to-Wheel energy efficiency (including air compression) would be much lower than for ICVs. In other words, compressed air vehicles would require far more primary energy to drive one km than ICVs.
   
• Huge air tanks weighting hundreds of kilos would only provide a driving range of a few tens of km.

Also, air engines are likely to be noisy.

Therefore, we do NOT support compressed air vehicles.