Do you know that the global population with the current trend may increase from 5.5 Billion up to 10 Billion by 2050? Vehicles in use may increase from 700 million to around 2.5-3 Billion by 2050. Would our environment sustain their consequences?
If all the vehicles will be the Internal Combustion Engine Vehicles (ICEV) then all cities may be covered with permanent smog with extreme air pollution as we have seen in recent times in New Delhi.
Thousands of people die per year due to fine particle matters around the globe.

Promising Solutions
  •         One of the major solutions should be of Sustainable Transport.
  •         Use of low or almost zero-emission vehicles.
  •         Promotion of public transport
  •        We must use renewable energy sources.
  •        We have to reduce dependency on fossil fuels.


Comparison of energy sources used for Transport

  •        Gasoline (Petrol & Diesel)

Petrol and diesel have similar energy content per unit mass, which means they have the same specific energy. Since diesel is denser than petrol it has higher energy content per unit volume.
Energy per unit volume = Energy Density
Diesel having higher density, therefore it is more fuel economical than petrol.
  •          CNG (Compressed Natural Gas)

CNG has higher specific energy as compared to liquid fuel (Diesel and Petrol) but has a very low energy density.
  •         Hydrogen

Hydrogen requires storage at the very highly compressed stage. Therefore it requires a lot of accessories around its fuel tank. But on the positive side, it has very high energy density as compared to diesel, petrol and CNG. That’s why researchers are in serious effort to make hydrogen-based fuel cell electric vehicles.
  •          Batteries

Battery like Li-ion battery has low specific energy and energy density around 75 times and 25 times compared to petrol. It means that for the same energy content, the mass of lithium-ion battery will be around 75 times more as compared to petrol and it requires 25 times more volume as compared to petrol. This is a very serious limitation of batteries as compared to liquid fuels.
  •          Ultra-Capacitors

Ultra-Capacitors stores energy in electrostatic form. It provides very high specific power and it can store very limited energy.
  •          Ultra-Flywheels

It can store energy in the mechanical form at very high speeds but it has a drawback such as it is reliable and there is a safety concern around it when it is used inside the electric vehicles.

Pollutants and Greenhouse Gases

  •         Particulate Matter PMx

Particulate matter is particles released as a part of the combustion cycle. These particles are extremely small therefore they can enter via nose and throat easily. It adversely affects the lungs and brain. These particles are cancerous in nature and it’s one of the major causes of having cancer due to air pollution.
Diesel Engine releases more PM as compared to Petrol Engine.
PM10 is the PM particles less than 10 micrometres.PM10 are very dangerous .If it is inhaled, can cause severe damage.
  •          CO, CO2, CH4, NOx are the greenhouse gases. Due to the presence of these gases the infrared radiations are trapped in the atmosphere and cause greenhouse gases such as climate change and global; warming.
  • CO is a colourless, odourless gas and is very lethal. A large amount of CO2 in the atmosphere and causes the greenhouse effect.
  • NOx gases, Volatile Organic Compound (VOC) and hydrocarbons are responsible for building ground-level ozone. So the ozone layer if it is present at ground level is very dangerous for humans. It can create a lining in the lungs and causes major respiratory illness such as Asthma and lung inflammation.
    So diesel engines are the main source of NOx gases. These gases can be filtered using Catalytic Converter but these devices are very costly.
    NOx gases can be minimised by the use of Urea filters.
  •        SOX  gases are released by coal-based thermal power plants. Sulphur dioxide reacts with oxygen and water present in the atmosphere and creates sulphuric acid which causes Acid rains.


So to avoid these conditions, regulating agencies are imposing hard regulations on emissions. For example Bharat Stage regulation in India, EURO regulations in Europe.


Comparison on Energy Diversification

BEV   : Battery Electric Vehicle
FCEV : Fuel Cell Electric Vehicle
ICEV  : Internal Combustion Engine Vehicle
PHEV  : Plugin Hybrid Electric Vehicle
HEV    : Hybrid Electric Vehicle

From the above illustration, we conclude that PHEV is the most energy diversified because it can run on both Liquid fuels and electric. And these two sources of energy have excellent response.

Comparison of Efficiency

( fuel tank to vehicle efficiency)



Advantages of Battery Electric Vehicle (BEV)
  •          Energy can be recovered during braking as regenerative power.
  •         It can be charged using renewable power which is pollutant free.
  •          It has the advantage of higher fuel economy than ICEV (Internal Combustion Engine Vehicle).
  •         It requires less maintenance, less noisy & is more reliable.
  •          It allows for high performance and smooth control.
  •          It can be charged by a renewable source like Solar.


Limitations of Battery Electric Vehicle (BEV)
  • BEV is much more expensive than ICEV due to initial battery cost and replacement of battery after a few years.
  •  For the same energy requirement, BEV requires more space and it's heavy.