Context: The Supreme Court has asked the government to look into the feasibility of hydrogen-based tech to deal with vehicular air pollution in New Delhi. India is looking closely at Japan, which has made progress in this field.
Prelims: Current events of naitonal and internaitonal importance.
Mains: GS III-
- Awareness in the fields of IT, Space, Computers, robotics, nanotechnology, biotechnology and issues relating to intellectual property rights.
- Challenges to internal security through communication networks, the role of media and social networking sites in internal security challenges, basics of cybersecurity.
- Fuel cells are electrochemical devices that convert chemical energy in fuels into electrical energy directly, promising power generation with high efficiency and low environmental impact.
- A fuel cell produces electricity, water, and heat using fuel and oxygen in the air. Water is the only emission when hydrogen is the fuel.
- As hydrogen flows into the fuel cell on the anode side, a platinum catalyst facilitates the separation of the hydrogen gas into electrons and protons (hydrogen ions).
- The hydrogen ions pass through the membrane (the center of the fuel cell) and, again with the help of a platinum catalyst, combine with oxygen and electrons on the cathode side, producing water.
- The electrons, which cannot pass through the membrane, flow from the anode to the cathode through an external circuit containing a motor or other electric load, which consumes the power generated by the cell.
- The voltage from one single cell is about 0.7 volts – just about enough for a light bulb – much less a car.
- When the cells are stacked in series, the operating voltage increases to 0.7 volts, multiplied by the number of cells stacked.
- Most fuel cell power systems comprise a number of components:
- a) Unit cells, in which the electrochemical reactions take place
- b) Stacks, in which individual cells are modularly combined by electrically connecting the cells to form units with the desired output capacity.
- c) Balance of plant which comprises components that provide feed stream conditioning (including a fuel processor if needed), thermal management, and electric power conditioning among other ancillary and interface functions.
How does hydrogen fuel cell work?
- At the heart of the fuel cell electric vehicles (FCEV) is a device that uses a source of fuel, such as hydrogen, and an oxidant to create electricity by an electrochemical process.
- Put simply, the fuel cell combines hydrogen and oxygen to generate electric current, water being the only byproduct.
- Like conventional batteries under the bonnets of automobiles, hydrogen fuel cells to convert chemical energy into electrical energy.
- From a long-term viability perspective, FCEVs are billed as vehicles of the future, given that hydrogen is the most abundant resource in the universe.
- The Fuel Cell Electric Vehicle (FCEV) combines hydrogen and oxygen to generate an electric current and water is the only byproduct.
- Hydrogen + Oxygen = Electricity + Water Vapour
- 2H2 (g) + O2 (g) → 2 H2O (l)
So is an FCEV a conventional vehicle or an electric vehicle (EV)?
- While the fuel cells generate electricity through an electrochemical process, unlike a battery-electricity vehicle, it does not store energy and, instead, relies on a constant supply of fuel and oxygen.
- It works in the same way that an internal combustion engine relies on a constant supply of petrol or diesel, and oxygen.
- In that sense, it may be seen as being similar to a conventional internal combustion engine.
- But unlike the combustion engine cars, there are no moving parts in the fuel cell, so they are more efficient and reliable by comparison. Also, there is no combustion on board, in the conventional sense.
Classification of Electric vehicles (EVs):
Globally, EVs are bracketed under three broad categories:
- Battery electric vehicle or BEVs:
- Such as the Nissan Leaf or Tesla Model S, which has no internal combustion engine or fuel tank, and run on a fully electric drivetrain powered by rechargeable batteries.
- Conventional hybrid electric vehicles or HEVs:
- Such as the Toyota Camry sold in the country combine a conventional internal combustion engine system with an electric propulsion system, resulting in a hybrid vehicle drivetrain that substantially reduces fuel use. The onboard battery in a conventional hybrid is charged when the IC engine is powering the drivetrain.
- Plug-in hybrid vehicles or PHEVs:
- Such as the Chevrolet Volt, too have a hybrid drivetrain that uses both an internal combustion engine and electric power for motive power, backed by rechargeable batteries that can be plugged into a power source.
What are the advantages and disadvantages of fuel cells?
- Fuel cells have strong advantages over conventional combustion-based technologies currently used in many power plants and cars, given that they produce much smaller quantities of greenhouse gases and none of the air pollutants that cause health problems.
- Also, if pure hydrogen is used, fuel cells emit only heat and water as a byproduct. Such cells are also far more energy-efficient than traditional combustion technologies.
- Unlike battery-powered electric vehicles, fuel cell vehicles do not need to be plugged in, and most models exceed 300 km of range on a full tank. They are filled up with a nozzle, just like in a petrol or diesel station.
Limitations of Fuel Cells EVs:
- While FCEVs do not generate gases that contribute to global warming, the process of making hydrogen needs energy — often from fossil fuel sources.
- That has raised questions over hydrogen’s green credentials.
- Also, there are questions of safety — hydrogen is more explosive than petrol.
- Opponents of the technology cite the case of the hydrogen-filled Hindenburg airship in 1937.
- The other major hurdle is that the vehicles are expensive, and fuel dispensing pumps are scarce.
Progress in India:
- In India, so far, the definition of EV only covers BEVs; the government has lowered taxes to 12%.
- At 43%, hybrid electric vehicles and hydrogen FCEVs attract the same tax as IC vehicles.
- The Ministry of New and Renewable Energy has been supporting various such projects in academic institutions, research and development organisations, and industry for development.