FCEVs in power demand. Vehicles with slower speed

FCEVs are also
categorized as zero-emissions as they are electrically propelled vehicles
powered by hydrogen emitting water. Fuel cell electric vehicles can typically
be categorized as all electric vehicle type, as it has very similar powertrain
to the BEV. The energy source of the car is from fuel cell stack that consumes
Hydrogen as the fuel producing electricity, water and heat as end products with
no exhaust pollutant, making it a zero emission vehicle. The fuel cell can be
of various types such as direct methanol fuel cells, alkaline fuel cells,
phosphoric acid fuel cells etc. The polymer electrolyte membrane is the most
preferred fuel cell for production cars. It has high power discharge and lower
operating temperature. It has high corrosion resistance compared to the other
types of fuel cells 30.  Highly
pressured hydrogen stored in a tank mounted in the vehicle is used as the fuel.

Fuel cell is the best options for a constant power supply but does not satisfy
the needs for a sudden change in power demand.


Vehicles with
slower speed like trams, buses, forklifts etc. are best fit for fuel cell
application. With recent technological advancement, fuel cells are designed and
used in high-speed vehicles such as cars. Asian Automakers like Hyundai, Toyota
and Honda have the leadership in this technology while producing high
performance fuel cells for their vehicles. Various energy management strategies
are adopted focusing on improved fuel economy, improved vehicle efficiency and
reduced energy losses.


General Electric
manufactured the first fuel cell electric car, the Electrovan in 1966. The Car
was powered by an alkaline fuel cell with two cooled tank vessels for liquid
hydrogen and liquid oxygen. The fuel cell stack is the main component of the
complete fuel cell power train. Based on temperature of operation a wide range
of fuel cells are available including mild and high temperature fuel cells. The
proton conducting polymer membrane type of fuel cell used in automotive
application operates at low temperature. They combine the hydrogen and oxygen
at a comparatively low operating temperature from 60 to 80 °C with high power density,
also with the potential of being manufactured at low cost. Polymer membrane
type fuel cell based power systems give similar
performance features compared with combustion engines. The stack for the fuel
cell is constructed from hundreds of single cells (similar to electric car
battery) converts’ chemical energy into electrical energy. The fuel (Hydrogen)
is channeled to the electrode through fuel supply system. Availability of ample
quantities of fuel and oxidants at the electrodes; result in the generation of
electrical energy. Removing of the end product, which is water, and the
continuous supply of fuel to the single cells of the stack is the challenge to
design the system. 34

The fuel cell
cars use a compressed hydrogen fuel storage system with either in 350 Bar or
700 Bar pressure. The single vessel tank system is used for the storage of
hydrogen with specific energy of 1600 Wh/kg. This results in 4-7 kg of hydrogen
that can be stored in the tank. 35 The ultimatum for production of fuel cell vehicle
is in terms of safety and ability to manufacture such high-pressure storage
tank for integrating into the car. Toyotas fuel tank for the latest Mirai
stores the high-pressured hydrogen in tanks that are capable of withstanding
small-caliber bullets. 36 In existing vehicles some level of modification is
need to accommodate the compressed hydrogen fuel tank. Conventionally designed
car for accommodating combustion engine does not have ample space for the
hydrogen storage to provide the range. Typically the rear body modifications must
be made to integrate the hydrogen storage.


The hydrogen fuel
cell is very effective alternative when used in vehicles that can accommodate
larger tanks to provide larger range such as trucks. The technology integration
in cars will definitely restrict the range of the car due to the low space
availability for larger storage tanks to accommodate the high-pressure
hydrogen. The primary set back of fuel cell vehicles to enter the system is the
lack of infrastructure for refueling of hydrogen. When adopted in cars, the
system itself is very expensive and the fueling stations are not availabile for
mass adaptation. Most countries currently have next to no hydrogen fuelling
stations. This makes the fuel cell vehicles highly impractical. Even though the
car does not produce harmful emissions, production of the fuel (high pressured
hydrogen) consumes a lot of energy. This does not balance the totality in the
supply chain.