Hybrid cars: How do they work?

An Advertising Feature

Hybrid cars are here. Quieter, cleaner, cheaper to run and making the best use of fuel than any car to date. They are the eco-friendly choice of the future, with most European governments now taking steps to incorporate them into their public transport. Red London buses have already begun to turn green and other countries are soon to follow. Hybrids are considered to contribute to the reduction of emissions and carbon dioxide by at least 30% when compared to ordinary cars. This all sounds promising but how does this technology actually work?

The technology behind hybrid cars

The hybrid car relies on two sources of energy: thermodynamic energy from the internal combustion engine and electric energy from the electric motor. For this combined use to be effective they also need batteries. A hybrid car can in fact move by using either motor or both at the same time, according to its movement. The electric motor is mainly used as a motor starter, and for low speeds. It is therefore ideal for urban areas where drivers need to frequently stop at traffic lights. The internal combustion engine, on the other hand, is used on motorways and open roads and it is best for travelling longer distances. The combination of both engines happens under heavy loads, such as overtaking and general acceleration.

Hybrid cars V Electric cars

Electric cars could have been the ecological answer to urban transport, and they have had their days of glory, but they present buyers with a serious flaw: they solely rely on batteries, which are bulky and expensive. Battery capacity deteriorates in time, due to the irregular charging and discharging cycles, which can make distant travelling quite uncomfortable, as it would require more frequent stops for recharge. Not to mention that recharging itself takes a few hours, whereas filling a conventional car with petrol takes no more than 5 minutes. In time the batteries will have to be replaced -and they don’t come cheap.

Hybrid cars came to solve all these problems. They consist of both an electric motor and an internal combustion engine. In simple terms their function is as follows: the chemical energy of the fuel gets converted into kinetic energy thanks to the internal combustion engine. The electric motor used is “regenerative”. By reversing its polarity it transforms the car’s kinetic energy into electric through braking and stores it in the batteries. This energy is used by the electric motor to either start or assist the internal combustion engine when required. As a result the engine doesn’t have to idle when the car is not moving. It can be reignited after a sort stop (e.g. a traffic light) using the already stored energy. Furthermore, the car can be set in motion with the help of both the electric motor and the engine, thus consuming less fuel. The same goes for all kinds of acceleration.

Hybrid cars therefore enjoy most of the benefits of electric cars while sharing none of the drawbacks. Whereas electric cars are heavily dependent on charge-points, hybrid cars function autonomously, as ordinary cars do.