Introduction
As electric vehicles (EVs) gain in popularity, many potential owners find themselves pondering two key questions: "Why do many electric vehicles have speed limits?" and "How does the range of EVs compare to traditional internal combustion engine (ICE) vehicles?" The answers to these questions lie in the fundamental differences between the energy sources that power these vehicles.
This article will explore the energy content of petrol and diesel compared to that of an electric vehicle's battery, shedding light on the reasons behind range differences and offering insights into future advancements in battery technology.
5 liters of petrol equals the energy of a 350kg high-voltage battery.
Energy Content of Petrol and Diesel
To begin understanding these differences, it's essential to consider the energy content of petrol and diesel, the two most widely used fuels today. One liter of petrol contains approximately 9 kWh of energy, while diesel contains nearly 10 kWh. This means that a typical compact car equipped with a 40-liter petrol tank would hold about 360 kWh of usable energy, while its diesel counterpart would hold around 400 kWh.
Energy Content of High-Voltage Batteries
In comparison, modern high-voltage batteries found in electric vehicles typically have a net energy content ranging from 50 to 80 kWh. The term "net" is crucial here, as not all energy in the battery is available for use due to necessary safety buffers at both the top and bottom of the charge cycle. These buffers help prolong battery life, but they also reduce the net energy available for driving. Manufacturers often recommend maintaining a charge level between 20% and 80% to maximize battery longevity.
Comparing Energy Sources
To illustrate the differences more clearly, let's compare three propulsion methods using the Peugeot 208 as an example:
| Model | Fuel Tank Energy Content (kWh) | Energy Consumption WLTP (kWh/100 km) | Range (km) |
| Peugeot 208 1.2 PureTech 130 PS EAT 8 | 396 | 47.7 | 830 |
| Peugeot 208 1.5 BlueHDi 102 PS | 410 | 40 | 1025 |
| Peugeot e-208 136 PS | 45 | 15.4 | 292 |
Conclusion
Current battery technology reveals that a conventional fuel tank typically contains nearly ten times more energy compared to an EV battery. However, the efficiency of electric vehicles mitigates this difference, as electric motors can achieve efficiencies of up to 94%, compared to 38-40% for modern petrol and diesel engines. To match the range of petrol and diesel models, a battery would need an impractically large capacity—approximately 128 kWh for petrol and 158 kWh for diesel.
Despite these challenges, advances in solid-state battery technology promise to close the gap, potentially offering longer ranges and faster charging times in the future.
The charging speed comparison further highlights the differences: Despite current EVs charging at a maximum of 270 kW, petrol and diesel vehicles can be "refueled" at a staggering 13,500 kW and 15,000 kW respectively, completing in mere minutes. While overnight charging can alleviate some range anxiety for EVs, further improvements in charging technology are essential for broader adoption.
Clearly, while traditional fuel sources offer a higher energy capacity, electric vehicles' efficiency and technological advancements could balance the scales in the not-so-distant future.
