The World Metrological Organization has declared 2021 as the hottest year ever. This year was about 1.11oC higher than the pre-industrial level. According to the Intergovernmental Panel on Climate Change (IPCC), governments around the world need to take several drastic measures to cut carbon emissions to prevent the global temperature from rising further than 1.5oC by 2050. In such a situation, EVs are no longer an alternative. They are the future and they must be the present. EV sales are increasing year-on-year but existing technologies which are used in EVs have their limitations. Through this cover story, we will explore the challenges that are present and the solution that have been discovered or are explored in transitioning towards electric vehicles. We will also briefly look at why self-driving vehicles are still far from becoming a reality and how the technologies that is associated with them makes existing vehicles safer.
Electric Vehicles and Electricity
Electric vehicles need electricity to charge their batteries. Internal Combustion (IC) engines and chemicals are among the options which can be used to generate electricity to charge the battery packs of an EV. The drive train in Battery Electric Vehicles (BEVs) is powered by a battery pack that is charged from the grid. The battery directly supplies electricity to the vehicle’s motors. Since it does not involve the conversion of energy from one form to another, they are the most efficient type of EV.
Hybrid electric vehicles have both an IC engine and a battery. The electric current generated by the IC engine charges the battery and the battery powers the motor only for a certain speed range and torque requirements and then the IC engine takes over. They are not very efficient since energy conversion from mechanical to electrical leads to loss of energy in the form of heat.
Fuel cell-based electric vehicles use chemical energy, say hydrogen, to convert it into electric current which is used to charge the battery and power electric motors. Storing Hydrogen in a light-duty vehicle is a challenge since its energy content by volume is low and building a fuel cell stack is expensive.
Plug-in hybrid EVs have both an IC engine and a battery. It can run on all-electric mode as well as a hybrid mode which employs both electricity and petrol/diesel engine. The battery can be charged directly from the plug. It gives the choice between fuel and battery.
What’s there inside an EV
EV and ICEV look almost alike from the outside but their internal components are completely different.
EVs have Traction Batteries instead of Internal Combustion Engine. This battery is the main powerhouse of an EV. Electricity stored in the traction battery is used to drive the vehicle and an auxiliary battery, similar to the battery used in ICE vehicles, is used to power the car’s accessories. In the BEVs, the traction battery is charged through the charging port from the grid.
The voltage supplied by the traction battery runs into several hundred volts. DC/DC converters are used to convert high-voltage DC into low-voltage DC in EVs for charging auxiliary batteries and powering electrical instruments such as lights, music systems, etc. The AC is converted into DC before the traction battery is charged by the onboard charger. It also monitors the characteristics of the battery like temperature, charge, voltage, current, etc. while charging the battery.
In ICE vehicles, the engine is connected directly to the wheels via the drive shaft. Since EVs have no engine, the battery directly powers the Electric Traction Motors. These motors drive the vehicle. The speed and torque of the EV are controlled by varying the current and voltage. The Power Electronic Controller manages the flow of current and voltage as per the requirement.
Temperature plays an important role in the performance of electrical equipment. The Cooling System maintains the proper temperature range for the electric motor and power electronics to ensure their optimum performance.
Why an EV?
The per kilometer running cost of an EV is way less than an ICE vehicle. It will cost even less if renewable energy is used for charging the vehicle. Since EVs don’t have a fuel injection system or an engine their maintenance cost is less than compared to ICE vehicle which needs regular replacement of engine oil and filters. They don’t cause any tailpipe emissions since no combustion takes place. EVs run so silently that some manufacturers are adding sound to make them safe for pedestrians.
Governments around the world are offering financial and tax incentives to individuals who are switching to EVs. In India, EVs are exempted from road tax at the time of purchase, and registration of EVs is free of cost. Under the rule 80EEB of Income Tax, EV customers opting for a loan will be eligible for tax deductions up to 1.5 lakh on interest paid on the loan amount. This rule is applicable for both 4-wheeler and 2-wheeler EVs. Fame Scheme is encouraging the faster adaptation of electric and hybrid vehicles by way of an upfront incentive on the purchase of EV.
Further elaborating on the government policies in the EV sector in India, Arindam Lahiri, CEO of Automotive Skill Development Council says, “The government policies in India have been so far encouraging for the auto industry in the country. From different EV policies by central and state governments to Production Linked Incentive (PLI) schemes, the government policies have been paving the way for growth in the auto industry. However, adopting the constant change in the industry is not just about a positive mindset but a matter of huge investment as well. An industry that is coming out of the pandemic gradually and slowly requires time to adopt the changes. The government too is expected to understand this situation and assist the auto industry accordingly.”
Companies offer a direct discount on the ex-showroom price of EVs. Various banks are offering discounted interest rates to individuals who are availing of loans for the purchase of EV. On scrapping old vehicles, the owners can avail of various incentives like a discount on the purchase of a new vehicle, waiver of registration fees of new vehicle and concession on road tax.
Battery, Their types, and the future ahead
Quintessential EV batteries are the ones that have lightweight, high energy density, high energy efficiency, good high-temperature performance and low self-discharge. Lithium-ion batteries fulfill many of these qualities and are widely used in consumer electronics and EVs. High Cost, Low Useful Self-Life, Thermal Runway, Less Stability and High Reactivity of Lithium are some of their drawbacks.
Lithium-ion batteries have a risk of battery damage due to swelling or leakage by external force since it has liquid electrolyte solution. Solid state Lithium batteries use solid-state separators which enables the use of Lithium metal as anode. They lower charging time and can hold 50% more charge. The search for the perfect material for solid electrolytes with perfect ionic conductivity is still ongoing.
Other kinds of batteries that are used in EVs are Nickel Metal Hydride batteries which have a longer life cycle and are safe and abuse tolerant. But the high cost, high self-discharge, heat generation at high temperature and need to control Hydrogen loss are some of their drawbacks.
Lead Acid batteries are used in every home inverter. They are high power, inexpensive, safe and reliable but they have low specific energy, poor cold temperature performance, and a short self-life cycle. They are generally used as an auxiliary battery in cars.
Ultra-capacitors store energy in the polarised liquid between an electrode and an electrolyte. It is used to provide the vehicle additional power during acceleration and hill climbing and help recover braking energy.
A team of researchers at IIT Madras has been working on Zinc Air batteries for the last 3 years. These batteries are water-based and are less expensive than Lithium-ion batteries. In Zinc-air batteries, only anode replacement is required rather than the entire battery.
Researchers are working on new alternative materials to make batteries cheaper and more efficient. Research has been going on to replace Cobalt as the cathode in Lithium batteries which is rare and expensive. Hybrid anodes by combining mesoporous Silicon microparticles and Carbon Nanotube are also being developed. Some researchers are experimenting to charge EVs by using wireless technologies like Ultrasound and Wi-Fi.
EV motors
The electric motor converts the electric energy stored in the battery to mechanical energy. For a long time, there was little or no development in the field of motor technology. EVs have given this segment a renewal push.
There are 3 types of motors that can be used in hybrid or plug-in electric vehicle traction drive systems. Internal Permanent Magnet motor uses rare earth permanent magnets which are made from the alloy of the rare earth elements. Due to the high cost of rare earth magnet and rotor fabrication, these motors are expensive. Induction Motors are the other type of motor in which the current needed to produce torque in the rotor is obtained by the electromagnetic induction from the magnetic field of the stator binding. These motors provide higher starting torque and high reliability but their overall efficiency is low compared to IPM motors. The third type Switched Reluctance Motor in which power is delivered to windings in the stator rather than the rotor. They work through a switching system that delivers power to different windings at different times. They produce a lot of noise and vibration and they require additional sensors and complex motor controllers that increase the overall cost.
Current research in EV motors focuses on reducing the use of rare earth metals, improving power and torque density, efficiency, and reducing the overall weight and cost of the motor.
Market and Industrial Scenario for EVs
According to a report by Allied Market Research, the global EV market was valued at USD 163.01 billion in 2020 and it is projected to reach USD 823.75 billion by 2030, growing at a CAGR of 18.2% from 2021 to 2030.
Factors like demand for higher fuel efficiency, high performance, and low emission along with stringent government rules and regulations towards vehicular emissions are pushing the growth of the electric vehicle market. The recent increase in fuel cost and reduction in the cost of EV batteries has made EVs a lucrative eco-friendly option.
In India, the EV market is expected to reach USD 206 billion by 2030 according to a report by the Centre for Energy Finance. It will generate an investment opportunity worth USD 180 billion. Indian Energy Storage Alliance estimated the EV market in India will grow at a CAGR of 36% till 2026 and the EV battery market at a CAGR of 30%.
“Indian auto industry is currently going through challenging times. These include the supply chain constraints especially the chip shortage, logistics issues, etc. However, the industry players have shown remarkable resilience in turning the tide toward positivity. With the supply chain constraints gradually improving and chip shortage subsiding, the industry is expected to witness a surging demand and sales moving ahead. Also, the upcoming festive season is likely to give the industry a shot in the arms, which is very much required at this phase.”, says Arindam Lahiri.
Challenges
EV’s future looks strong but marred with challenges. Public fast-charging infrastructure is available only in a few cities and on selected highways. Range anxiety is one thing that all EV owners suffer. The manufacturing cost of EVs is way more than an ICE vehicle which leads to a costly end product. The service requirement of an EV is very different from an ICE vehicle. Indian prefer road-side mechanics over company-authorised service centers due to affordability and quick service. There are very few trained road-side mechanics for EVs which makes their serviceability difficult.
Further explaining the challenge in EV adoption, Mr. Vinod Aggarwal, President, ASDC says, “Electric vehicles in India are still at a nascent stage, despite the interest and positive consumer sentiment. Though we are experiencing a boom in the two-wheeler and three-wheeler segments, passenger vehicles and commercial vehicles are yet to pick up momentum. EV adoption in India has seen a few significant challenges, which are – high cost compared to their ICE counterparts, beta versions of electric vehicles, poor charging infrastructure and range anxiety, lack of standardisation, very little academic and local skill awareness, lackluster vehicle performance compared to ICE counterparts, etc. Recent fire eruption cases and the hue and cry involving EVs too have become another challenge impacting the consumer sentiments.”
Calling customers another pillar of the turnaround story, on an optimistic note, Mr. Lahiri adds, “If auto OEMs and their component suppliers have been one pillar of the turnaround story for the Indian auto industry, customers have been another pillar. Despite the initial hiccups due to the pandemic and other adversaries, Indian automobile customers remained upbeat and resilient and helped the industry to stand on its feet again. Also, they have been very optimistic about the changing trends as well. This momentum is expected to continue in the coming days as well.”
Autonomous Vehicle
Another development that is ongoing in the mobility field along with the EV is in Autonomous Vehicles. Autonomous vehicles are capable of sensing their environment and moving safely without any human intervention. They deploy a variety of sensors like Thermographic Cameras, Radar, Lidar, Sonar, GPS, Odometry, and Inertial Measurement Units to perceive their surroundings.
The society for Automotive Engineers (SAE) has classified driving automation into 6 levels:
- Level 0 (No Automation)- The driver performs all the tasks in the vehicle.
- Level 1 (Driver Assistance)- The vehicle features a single automated system like Automatic Gears.
- Level 2 (Partial Automation)- Advance Driver Assistance System can be part of this where the system performs steering and acceleration. Human still monitors and can take control at any time.
- Level 3 (Conditional Automation)- In this category vehicles has Environmental detection capabilities but human is still required for monitoring.
- Level 4 (High Automation)- Vehicles performs all the driving task under specific circumstances. Human overrides are still an option.
- Level 5 (Full Automation)- The vehicle performs all the tasks. Zero human attention or interaction is required. Level 5 automation vehicles are still under trails and are not commercially available yet.
Autonomous vs Automated
Autonomous vehicles are the ones that can take their own decision. For ex: If an individual commands his vehicle to take him to the office instead his car takes him to a hospital. Automated vehicles follow orders and then drive themselves. All the development in the field of Autonomous vehicles is actually towards Automated vehicles.
Self-driving
Self-driving is used interchangeably with Autonomous vehicles. Self-driving can drive itself in some or all situations. It falls under level 3 or level 4. It is subjected to Geofencing whereas level 5 vehicles can go anywhere.
Self-driving vehicles rely on Sensors, Actuators, Complex Algorithms, Machine Learning systems, and powerful processors to execute software. Mapping of the surrounding is done using radars. Video cameras capture 360o to detect traffic lights, read road signs, track other vehicles and look for pedestrians. Lidar (Light Detection and Ranging) sensors bounce phases of light in the car’s surroundings to measure distance, detect road edges and identify lane markings. Software processes the sensory inputs, plots paths and sends signals to the car’s actuators which control acceleration, braking and steering.
Although many big names in tech and automaking made many extraordinary attempts but fully autonomous are still not available except in some special trial programs. The technology associated with autonomous vehicles is available in the form of ADAS in cars at various levels of automation.
Challenges
Many technologies associated with the autonomous vehicle are expensive and the balance between range and resolution is still under development. Different weather condition requires different driving skill because road condition changes. Collecting a huge amount of training data to train self-drive cars is expensive and some events, say, encountering a tree fall during rain, which humans can predict while driving on road by looking at the tree’s condition, are rare to train a self-drive car.
Traffic condition never remains ideal. In metro cities, people drive their vehicles bumper to bumper. In such a situation it will become difficult for an autonomous vehicle to drive itself. Most drivers use hand signals and emotional intelligence to convey their direction and understand others’. Such things are beyond the capabilities of autonomous vehicles.
Conclusion
There is an urgent need to adopt viable greener options as quickly as possible. When Edison invented light bulbs, they were consuming more than 100W in 1 hour. Now with LEDs, we get the same luminescence in 5W. EVs with the current technologies have many limitations but researchers are exploring new technologies, and materials to make EVs on par with ICE vehicles. With the current pace of technological development, we will soon have EVs capable of charging running for 1000 km in 5 minutes of charge. Although self-drive cars are still far from becoming a reality due to obvious challenges, the technological development in these areas like ADAS, and 360o cameras have made existing cars way safer. EVs coupled with automated driving options will surely make our future greener and safer.
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