In part 1 we looked at the history and comparison of electric vehicles to ICE vehicles. We saw how EV technology changed with advances in battery storage technology, finally becoming commerciallly viable with lithium ion batteries. Vehicles with zero tailpipe emission is no longer a pipe dream. Let us analyze why EVs are so useful.
Alternate energy sources
Solar, wind, hydroelectric, and nuclear power can be harvested for EV usage. No more would we have to depend wholly on gasoline. Thermal power plants run on fossil fuels produce the majority of earth’s energy sitting at 59%. Renewable sources are increasing and, most importantly, nuclear sources are finally shedding the stigma associated with it. Nuclear power is the energy of the future and two failures, namely Chernobyl and Fukushima, should not overshadow the other reactors currently operational. Nuclear fuel waste has seen vast research in recycling technologies and 30% has currently been reprocessed.
Higher energy efficiency
EVs have higher “well-to-wheel” (WTW) efficiency than ICE vehicles. Well-to-wheel is a term used for measuring the energy consumed from the point of primary resource extraction through processing, transportation and final propulsion at vehicle’s wheels. In a 2020 research conducted by Aiman Albatayneh et. al, results show that gasoline ICE have a WTW of 11-27% and diesel ICE have a WTW of 25-37%. EVs have the advantage of multiple energy sources, every energy source will have a different WTW associated to it. Coal-fired sources have 13-27%, natural gas has 13-31%, and diesel generated electricity will have 12-25%. These figures seem to be lacklustre when compared to ICE WTW but engines cannot utilize renewable sources. Local solar photovoltaic sources have a WTW of 42-72% and a combination of solar farms and wind farms will have a WTW of 39-67%. EVs show their real utility when there are no ‘wells’ or drilling involved. This study does not cover nuclear energy and I am sure it would make these results even more promising.
Better performance and driving experience
No engine means no combustion and that gives us no vibration. Sitting in an EV feels as if you are gliding. Electric motors have the property of instantaneous torque. Motors can give near maximum turning force immediately after pressing the accelerator, resulting in faster acceleration. Electric motors have a wide range of usable rpm which allows single speed transmission reducing the response lag caused by multispeed transmission. These are just some of the performance benefits of an EV.
Regenerative braking
This is my favourite feature in EVs. It is the most popular feature due it being advertised so aggressively. Lets figure it out.
The difference between an electric motor and an electric generator is the conversion of energy happening. If electric energy is the input, mechanical energy is the output, it acts as an electric motor and vice versa is a generator’s operation. The construction remains the same, the same stator and rotor. The motor is controlled using power electronic circuits that are bidirectional in nature.
When we apply acceleration, the controller sends current to the motor depending on demand, high acceleration requires high current. Taking your foot off the accelerator ceases forward current supply, now the motor has freedom to act as a generator because the wheels are spinning and providing mechanical energy input. This power can be converted to electrical energy and stored in the battery. Regen braking is a bit harsher than engine braking due to the magnetic field being generated in the opposite direction to the wheel rotation (Lenz’s law). For harsh braking, the controller requests a larger magnitude of current to generate a greater reverse magnetic field. When it reaches a slow enough speed, regen braking does not work and friction brakes take over. Brake clamps are used very sparingly compared to ICE drive cycle.
Lower operating costs
Let us compare the operating cost of an EV and HEV to its comparable ICE counterpart. We will choose three vehicles in the compact SUV segment, with similar functionalities. We are assuming the electricity price in India as INR 8/ kWh or INR 8 per unit, average petrol price for the next 10 years as INR 125/L due to the fast increase in petrol cost, and after 10 years the car will have travelled 150,000 km. Electric vehicles require less maintenance than ICE and hybrid vehicles due to the lack of an engine. Hybrid vehicles save on brake maintenance due to regenerative braking.
Table 1: Lifetime price comparison. (Reference data: Carwale)
| Parameter | Mahindra BE 6 Pack Three | Toyota Urban Cruiser Hyryder V Hybrid | Hyundai Creta SX(O) Premium Petrol |
| Powertrain | Electric | Strong hybrid | Turbo Petrol ICE |
| Approx ex showroom price | INR 27.65 lakhs | INR 20.19 lakhs | INR 17.93 lakhs |
| Claimed efficiency | 8.64 km/kWh | 27.97 kmpl | 18.5 kmpl |
| Energy/fuel consumption over 10 years | ~ 17361 kWH | ~ 5362 L | ~ 8108 L |
| Cost of energy/fuel over 10 years | INR 1.4 lakhs | INR 6.7 lakhs | INR 10.1 lakhs |
| Approx cost of maintenance | INR 2 lakh | INR 4 lakh | INR 5 lakh |
| Total cost after 10 years | INR 31.05 lakks | INR 30.89 lakhs | INR 33.03 lakhs |
All the estimates taken are very conservative. The price of ICE vehicles do rise by 2 lakhs when compared to EVs and HEVs. Increasing advances in EV technology promises to make them more affordable and accessible.
V2G technologies
Time-of-day pricing is a concept that is gaining popularity, it means that pricing of electricity depends on the hour of the day. In the day time when electric appliances find the most use, prices will surge and in the night when most of your appliances are off, the price dips. This is done to reduce the load on the grid. If only there was a way where you could charge for cheap and sell the stored electricity for a higher price. Your EV can become a stockbroker’s dream, buy low, sell high. EVs have been given another term as a ‘mobile asset’ for this reason.
Wow, EVs are pretty good, where is the cost you keep harping on about? Well not to worry, dear reader, because our next part, i.e, part 3 deals exclusively with this.
Frequently Asked Questions
What is torque?
Torque is the rotational force that causes an object to turn around an axis. In vehicles, torque is what helps the wheels rotate and move the car forward. Higher torque usually means stronger acceleration and better pulling power.
What is well to wheel efficiency?
Well-to-wheel efficiency measures how efficiently energy is converted from its original source into movement of a vehicle. For gasoline cars, it includes oil extraction, refining, transport, and engine combustion losses. For EVs, it includes electricity generation, transmission, battery charging, and motor efficiency.
What is back EMF?
Back EMF (back electromotive force) is the voltage generated by an electric motor when it spins. This voltage opposes the applied voltage and naturally limits the current flowing through the motor. In EVs, back EMF is important for controlling motor speed and efficiency, and during regenerative braking, where the motor acts like a generator and sends energy back to the battery.
What is V2G?
Vehicle-to-grid (V2G) is a technology that allows electric vehicles to send electricity back to the power grid. Instead of only charging, EV batteries can temporarily supply stored energy during periods of high electricity demand.
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