10 March, 2022
Author - Mr. Anand Kulkarni, Vice President, Product Line & Operations, Tata Passenger Electric Mobility Ltd.
With global organizations decisively highlighting the urgent need to migrate to cleaner forms of mobility, leading nations have enacted focused efforts to accelerate the electric vehicle (EV) revolution in the automobile industry. Growing environmental consciousness and an increased awareness about the benefits of EVs has stirred consumer interest and the demand for EVs is expected to rise substantially in the next decade. In India too, both central and state governments have come up with comprehensive initiatives to incentivize EV adoption. Yet, as of today, overall EV penetration in India is very low, at 0.8%1.
While there are a couple of reasons for this, such as higher costs and the lack of charging infrastructure, another related concern is that of range anxiety. 64% Indian drivers agree that range anxiety is a major barrier to the mainstream adoption of EVs2. Battery EVs (BEVs) carry a finite amount of energy on board, and even today, recharging takes significantly longer than what it takes to refuel an Internal Combustion Engine (ICE) vehicle. Range is therefore one of the most critical aspects governing the usability of BEVs. So how can this major barrier be effectively addressed to accelerate EV adoption in India?
Efficient energy management: The foundational solution to range anxiety
When it comes to solving for range anxiety, there are broadly 3 approaches one could think of. The instinctive option is increasing battery capacity, however beyond a certain point, packaging, weight and costs become significant issues. The second answer for an improved range in EVs, is to strive to improve energy efficiency within a given battery capacity. Finally, given these two approaches, one could also adopt a hybrid approach of increasing battery capacity as well as maximizing energy efficiency.
As is evident, the cost-effective answer for range improvement is energy management. Energy management inherently imbibes the essence of sustainability by its endeavour to minimize energy wastage within a vehicle as much as possible. Effective energy management entails optimizing energy consumption within a vehicle without affecting performance, driveability and comfort. The fundamentals of energy management in an EV and an ICE vehicle however, are different, and it is crucial to keep this in mind.
ICE vs EV: Key differences in energy management
Energy management is different in an ICE vehicle from an EV primarily because a majority of engine losses are absent in an EV. The most efficient combustion engines available on the market today have a fuel efficiency of less than 37%. This means they can convert only about 37% of their fuel energy into energy used for traction and to power onboard accessories. The rest is lost in overcoming friction on moving parts, and heat through exhaust and surface radiation.
In contrast, EV motors have very high fuel efficiency, and therefore intrinsically are able to convert a large part of available energy for traction. Consequently, the proportion of energy consumed through major aggregates changes significantly in an EV. Vehicle losses, such as rolling and aerodynamic losses, thermal management and ancillaries become important areas of focus when designing a vehicle for optimal energy efficiency.
Covering all fronts: Key areas to consider for energy efficiency
There are several areas within an EV that can be effectively optimized. Within the vehicle itself, improvements in aerodynamics, rolling losses and overall weight reduction can impact a vehicle’s energy in a significant way. This includes choosing the right body style, balancing packageability, dynamics, aerodynamics and cost. Besides this, minimizing rolling losses—the energy lost from tyres, is an area that industry is keenly focusing on. Typically, a 10% improvement in rolling losses, leads to an improvement of 2% range in the city and up to a 3% range improvement on the highways.
Optimized thermal management is another key area in this regard. Using appropriate and effective cooling in electronic parts like the E-Drive, power unit and battery can potentially help gain 3-5% more efficiency. Moreover, unlike ICE vehicles, EVs have the unique ability to regenerate energy. An EV motor considerably recovers the vehicle’s kinetic energy while decelerating, while in an ICE this entire kinetic energy is lost through brakes. Employing appropriate regenerative strategies can therefore have a decisive impact in energy efficiency. Finally, load reduction of ancillary consumers of energy in a vehicle, such as pumps, lamps, fans, etc. have a relatively lesser, but noteworthy effect in optimizing energy consumption.
The biggest challenge ultimately is to manage all these levers and deliver a product within the development cycle. Evidently however, energy efficiency across levels can play an instrumental role in maximizing range in EVs. As we move into an era of cleaner fuels and sustainable practices, incorporating the same values in the very development of our vehicles is also necessary. Efficient energy management not only solves for the pertinent barrier of range anxiety but also offers automotive developers an opportunity to incorporate minimum wastage as a core value of well-performing vehicles.