The automotive industry has been witnessing development of several alternate fuels for the energy source of vehicles, but there is one source that has been waiting to become the next big technology. We are talking about hydrogen as a fuel as well as hydrogen fuel cells as an energy source for vehicle propulsion.
The most widely talked about hydrogen vehicle propulsion technology is hydrogen fuel cell vehicles (FCV). Toyota Motor Corporation, Honda Motor Company and Hyundai Motor Company have been the leading OEMs developing hydrogen fuel technologies. However, over the past few years, a number of other companies have also focussed on developing hydrogen-based propulsion systems and technologies through a large number of collaborations.
The hydrogen fuel revolution received a major push in 2015, when Toyota decided to offer free access to its intellectual properties around hydrogen fuel cell technologies. While this initiative put the company at the forefront of all hydrogen-related development work, it provided the automotive industry with a wealth of knowledge on this technology and enabled other stakeholders to assist in its further development.
HYDROGEN PROPULSION SYSTEMS
Hydrogen can be burned in an internal combustion engine to convert its chemical energy into mechanical energy. However, the largely-adopted form of hydrogen as a fuel is in the case of FCVs. Therefore, it is appropriate to say that hydrogen vehicles are essentially electric vehicles, since they are powered by an electric motor to drive the wheels. Fuel cell vehicles combine hydrogen and oxygen to produce mechanical energy, which is subsequently used to power an electric motor. However, the driving range and refuelling processes of such vehicles are more comparable to conventional internal combustion engine vehicles.
An electrochemical cell is present inside the fuel cell of the FCV that carries out the process of combining the stored hydrogen with oxygen from the air and creating electricity to drive the electric motor present in the vehicle. And to break this down further, when hydrogen is introduced into the fuel side of the cell, a membrane breaks the chemical into protons and electrons. This membrane is not just an electron barrier but a proton carrier, which effectively means that the electron takes an external path and paves the way for creation of mechanical energy that powers the electric motor. Once this electron completes its journey beyond the motor, it combines back with the proton on the air side of the fuel cell to create water vapour as the only element of emission.
As mentioned, in the process of creating energy to power the motor in a FCV, converting hydrogen gas into electricity produces only water and heat as by-products. This means FCVs do not cause tailpipe emissions, making them one of the most ideal forms of propulsion technology. The fuel cell itself combines hydrogen with atmospherically-present oxygen, thereby making the propulsion system highly-efficient. FCVs would provide users with an improved value-for-money option as compared to conventional internal combustion engines.
In addition, since hydrogen can be used to power internal combustion engines as well as electric motors, it offers the industry a viable option for a hybrid powertrain system. Hybrid systems generally leverage two different fuel sources to power – an internal combustion engine as well as electric motors. However, in the case of hydrogen, the same fuel can be used to power two propulsion systems, thus enabling the vehicle to be hybrid.
The main issue with hydrogen as a fuel source is in its production . The most common method of hydrogen production is through thermolysis using natural gas. This process of manufacturing hydrogen, while being efficient, leads to the emission of greenhouse gases. While there are other processes of producing hydrogen, they have a lower level of efficiency and require large amounts of energy to carry out the production.
Another factor that has been a negative for the use of hydrogen as an energy source is that the cost of producing fuel cells is high. Some of the materials required in the construction of the fuel cell as well as the expertise required in their production itself are responsible for the high manufacturing price. Since the fuel cell is the most integral part of FCVs, it becomes one of the high-value components in the vehicle. This results in the overall cost of the FCV going up, thus resulting in consumers preferring other cheaper vehicle technologies.
The most common challenge in the adoption of any new source of fuel is with the infrastructure requirements. This challenge is applicable to hydrogen as well since the storage tanks for hydrogen also require engineering and construction with precision. This increases the cost of setting up hydrogen fuel infrastructure, which is a deterrent, especially since the number of users of this technology is low to begin with.
While a number of companies have been working on technologies to enable hydrogen as a fuel source for the automotive sector from the 1970s, various governments have also carried out some work in this regard. The International Partnership for Hydrogen and Fuel Cells in the Economy (IPHE), which was established in 2003, is an international inter-governmental partnership of 18-member countries and the European Commission. IPHE’s objective has been to speed up the move towards cleaner and more efficient mobility systems, using hydrogen and fuel cell technologies. The focus of the body has been on accelerating the market penetration of hydrogen and fuel cell technologies and their supporting infrastructure.
As per a demonstration and deployments update provided by IPHE for 2017, India accounted for the implementation of 26 Research, Development and Demonstration (RD&D) projects on different aspects of hydrogen energy and fuel cell technologies. These projects were being funded by the Ministry of New and Renewable Energy. The Ministry’s RD&D programme focussed on hydrogen production from renewable routes; development of materials & techniques for safe storage of hydrogen; and types of fuel cells, including materials, components and sub-systems. Other areas of research included demonstrations for stationary power generation and transportation; and support development of hydrogen energy infrastructure in the country.
While the IPHE was set up in 2003 to address the adoption of hydrogen fuel, India’s National Hydrogen Energy Board (NHEB) also initiated its National Hydrogen Energy Road Map the same year. This programme aimed at bridging the technological gaps in different areas of hydrogen energy, covering production, storage, transportation and delivery, applications, safety, codes and standards, and capacity building of hydrogen for the period up to 2020. The programme was focussed towards promoting the use of hydrogen as a fuel for transport as well as power generation. It also had a goal to generate 1,000 MW electricity using fuel cells by 2020 as well as have one million vehicles running on hydrogen-based internal combustion engines and fuel cells over the same period.
The various initiatives undertaken by government bodies with regards to the acceleration of hydrogen technologies appear to be visionary and ambitious. The present status of most of these programmes seems to suggest that they have lost steam as compared to other alternate propulsion system technologies in the automotive sector. There has been little local development of hydrogen technologies by domestic companies in the automotive industry and nothing worthy of mass adoption.
However, the automotive industry is witnessing a growing number of global collaborations for development as far as developing hydrogen as an energy source for the automotive industry is concerned. These collaborations are not only bringing together OEMs and suppliers for fully-built hydrogen-powered vehicles, but also for FCV components as well as vehicle systems. This ecosystem approach will hopefully result in improved work in the area of hydrogen systems so as to make the technology more viable for higher adoption by the automotive industry, which is reeling under stringent regulations across the globe in a bid to drastically cut the level of emissions of vehicles.
Much of the preceding content concludes that producing hydrogen itself can lead to pollution. However, it must be noted that even when hydrogen is procured from one of its dirtiest sources – natural gas, FCVs can cut emissions by over 30 % as compared to petrol-powered counterparts. Many believe that future renewable fuel standards, similar to those prescribed by the US Department of Energy, could make hydrogen even cleaner. In conclusion, the use of hydrogen as a fuel or in fuel cells may not be a viable option for personal vehicles for some time to come. However, its use as a fuel may be introduced for the long-distance transportation of people and goods, due to eminent qualities of being emission-free combined with offering a longer driving range than EVs or internal combustion vehicles.
(Inputs from Ministry of New and Renewable Energy, IPHE, US Department of Energy, Toyota)
TEXT: Naveen Arul