Hybrid vehicles - Bridging the power divide
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A guide to hybrid vehicles and the various forms available.
There is no doubt that motorists are in the middle of a time of major change. In terms of what powers a car, there are currently three distinct types of fuel to be considered: petrol/diesel, electricity and hydrogen. With regards to the latter, although some hydrogen powered cars are on the market, it is still yet to make a real impact.
So it boils down to a choice of two sources of power: internal combustion (petrol/diesel) or electricity… except that life is rarely that simple and somewhere between the two sit hybrid vehicles, which are pretty much what you might expect: a combination of both electric and internal combustion units.
Hybrids have been with us for more than two decades, and most car manufacturers offer a hybrid in their range… but hybrids themselves are not a one size fits all solution, so let’s examine the various types of hybrid on offer and what differentiates them.
Hybrids split into four basic types:
- Full hybrids – also known as “self-charging” or FHEV/HEV
- Plug-in hybrids or PHEV
- Mild hybrids or MHEV
- Range extending electric vehicles or REEV
Full hybrids
A full hybrid uses regenerative braking – taking the energy created by the engine when the car brakes, as it is being driven, to help charge up the battery. This is why they are often referred to as self-charging.
Full hybrids can be driven using solely the combustion engine, or only on electric power, or a combination of both. This means that you don’t have to plug them into a charger, so they are the most straightforward hybrid to use.
Plugin hybrids
As is apparent from the name, plug-in hybrid electric vehicles – PHEVs for short – need to be plugged into an electricity supply in order to recharge the battery that powers the electric motor/s.
Many consider them to be the most versatile of hybrids, and perhaps of any vehicles around, because they can offer the driver different modes of travel, so you can choose the one that offers you whatever suits your needs most.
There is the option when you use the electric power to either make the car more economical, or to use the additional power available to make the car more powerful and, therefore, faster.
Plug-in hybrids have larger batteries than other hybrids, which gives them an increased electric only range. The compromise, however, is that their range on fuel alone is less, because of the additional weight of the battery. If you want to make the most of the benefits they offer, it also tends to mean that they need to be charged more often, however, this is like charging any other electric vehicle, and so is a fairly simple exercise.
Mild hybrids
The prime difference between mild hybrid electric vehicles and any other hybrids comes from the fact that the electric and internal combustion motors always work together.
Although many consider them to be the entry level hybrid, the technology makes them more fuel efficient and therefore more economical than their petrol or diesel equivalents. In addition, most feature Stop/Start technology, which makes them especially suited for driving around town.
Range extended electric vehicles
These are, in many ways, the opposite of all of the other types of hybrid, because rather than an internal combustion engine being the main - or a major - source of power, here the vehicle is primarily electric. However, they are equipped with a small petrol engine, which offers a back-up when the main electric power source runs down.
The range extension engine does not directly power the vehicle, it is there only to recharge the battery that powers the electric motor/s.
As one of the major issues of owning an electric vehicle is range anxiety, that is, the fear of running short of battery power and being stuck somewhere without any easy way of recharging, a range extender might well offer the additional peace of mind required by a driver to make a switch from an internal combustion engined vehicle to electric power.
A wide variety of choice
One thing to bear in mind with any hybrid, however, is that because in each case, they incorporate two completely different forms of motive power, they are generally more expensive to purchase than either an internal combustion engined car or a full electric vehicle and over its life, both of the units and associated systems will require servicing and maintenance.
However, in many ways, a hybrid is the best of both worlds and today, with most vehicle manufacturers offering some sort or another, the choice is huge, from city cars, through saloons and SUVs, all the way up to supercars!