In this blog post, we will examine the concept and operating principles of hybrid vehicles, as well as their pros and cons and prospects for commercialization.

The Concept of Hybrids and the Operating Principles of Electric Motors

Do you remember cell phones from the early 90s? Back then, cell phones were just heavy devices capable of making calls, but today they have evolved into smartphones that perform countless functions—such as making calls, searching the internet, messaging, taking photos, and playing games—all in a single device. This is precisely where the concept of a hybrid lies. A hybrid is defined in the dictionary as “the combination of two functions or roles into one to create new added value.” In the example of the cell phone mentioned earlier, various functions were combined with the basic calling function to create a new product: the smartphone.
Hybrid cars follow the same concept. A hybrid car is a vehicle that combines two power sources—introducing an electric motor as a new power source to a vehicle that previously used only a gasoline or diesel engine. These vehicles aim to improve driving efficiency and reduce emissions by utilizing the gasoline engine and electric motor according to the situation.
The electric motor in a hybrid vehicle generates powerful electricity and is capable of charging and discharging. For example, when a vehicle decelerates, a hybrid car shuts off the gasoline engine and runs solely on the electric motor, recovering the kinetic energy from the deceleration as electrical energy to charge the battery. Conversely, when climbing hills or accelerating, it discharges the electrical energy stored in the battery to assist with kinetic energy. This ability to freely convert between electrical and kinetic energy while functioning as an auxiliary power source is the core role of the electric motor.

Advantages: Efficiency and the Environment; Disadvantages: Price, Weight, and Batteries

So why did engineers around the world seek to install electric motors in cars to create hybrid vehicles? There are two main perspectives. The first is efficiency, and the second is environmental concerns. The phrase “two hearts,” emphasized in Hyundai Motor’s Sonata Hybrid advertisement, aptly describes the efficiency of a hybrid. It involves adding an electric motor—the auxiliary heart—to the gasoline engine—the primary heart—to enhance the overall system’s efficiency.
When using only one heart, a significant amount of fuel is consumed to keep the engine running, but a hybrid reduces fuel consumption by using the electric motor in parallel. For example, when stopped at a traffic light, a gasoline vehicle wastes fuel by idling the engine, whereas a hybrid vehicle automatically shuts off the engine and runs solely on the electric motor, thereby reducing fuel consumption. Fuel efficiency improves as the electric motor takes over some of the functions previously performed by the engine. It is said that the fuel efficiency of a hybrid vehicle is approximately twice that of a standard gasoline vehicle.
Reduced fuel consumption also leads to lower exhaust emissions, contributing to environmental conservation. This is because emissions of carbon monoxide and nitrogen oxides—which result from the incomplete combustion of gasoline—are reduced.
This may raise the question: “If that’s the case, aren’t electric vehicles that run solely on electric motors better?” Electric vehicles incur no fuel costs and produce almost no exhaust emissions, making them potentially more eco-friendly. However, current technology imposes limitations on the widespread adoption of electric vehicles. In many cases, the driving range on a single charge is limited to 200 km or less; they are expensive; and the driving range drops sharply when using the heater or air conditioner, among other practical limitations.
Despite these many advantages, hybrid vehicles are not commonly seen on the streets due to several critical drawbacks. First is the issue of price. Even with similar performance, hybrid vehicles are more expensive than gasoline-powered ones. For example, as of 2013, some gasoline-powered Sonata models could be purchased for around 20 million won, but the hybrid version of the same model cost over 30 million won.
Additionally, hybrids require additional components such as electric motors and batteries, which increases the vehicle’s weight. Increased weight can lead to reduced fuel efficiency and a higher probability of breakdowns. Finally, there is the issue of battery lifespan. Battery life typically ranges from 6 to 8 years, and replacement costs can be a significant burden, ranging from 3 million to 6 million won depending on the vehicle. Battery-related costs are one of the key factors hindering the widespread adoption of hybrid vehicles.

Prospects for Commercialization

We have examined the concept and pros and cons of hybrid vehicles. Born from the fusion of gasoline engines and electric motors, hybrid vehicles significantly outperform conventional gasoline vehicles in terms of efficiency and environmental impact, and initial issues regarding price, weight, and batteries are gradually being resolved through technological advancements.
Nevertheless, the shift in the market is becoming increasingly evident. Recent statistics show that hybrid vehicle sales are on a steady upward trend. Since the 2020s, global hybrid vehicle sales have expanded to the scale of millions of units annually, and they have established themselves as a key alternative alongside electric vehicles in the transition to electrification. In South Korea as well, the share of hybrid vehicle sales has been steadily rising, with some models even recording a higher sales share than their gasoline counterparts.
If the aforementioned drawbacks are gradually resolved through technological advancements and economies of scale, the adoption of hybrid vehicles will expand even more rapidly in the future. Hybrid vehicles are already just as common on the roads as gasoline vehicles, and this trend is expected to continue for the foreseeable future.