ELECTRIC VEHICLES EXPLAINED
THE DIFFERENCE BETWEEN A REGULAR CAR AND AN ELECTRIC CAR
Conventional petrol/diesel cars and vans have an internal combustion engine whereby the fuel is burned inside the engine and releases energy that moves the car. A petrol engine has spark plugs to ignite the fuel whereas diesel engines use injectors and pressure to create energy. Each tiny explosion within the cylinder provides the motive force to turn the wheels but also drives the ignition of the next explosion.
There are various types of electric vehicles; Battery electric and pseudo or hybrid electric vehicles (HEV) ie. ones assisted by a petrol engine. A further type of electric vehicle is the hydrogen fuel cell vehicle. In Battery Electric vehicles, (BEV / Pure Electric cars) the latest generation of rechargeable batteries includes lithium-ion (Li-Ion) and lithium-polymer (Li-Poly) cells. These provide a significant improvement in performance and vehicle range compared to lead acid batteries. An on-board battery also enables the use of regenerative braking which tops up the battery during braking and reduces overall energy use by up to 20% and also reduces wear on the brake pads. In this way, all plug-in vehicles provide improved fuel economy and either zero or reduced emissions at point of use.
BATTERY ELECTRIC / PURE ELECTRIC VEHICLES (BEV's)
Battery electric vehicles have no combustion engine and derive all their power from electricity, usually through the electrical grid but also through micro grids. They receive electricity by plugging into a power source and storing the energy in the batteries. Most models can be plugged into a 240 volt standard 3 pin socket but it is most practical and quicker to use a dedicated home charger supplying 7 kW of power as opposed to a 3 pin supplying 3 kW. Battery electric vehicles consume no petrol/diesel and produce no exhaust pipe emissions. Most new models have a range in excess of at least 120 miles but earlier models from 2013 onwards may have between 60 and 80 miles, more than sufficient for the Channel islands. Battery technology is advancing quickly and new models are being launched with much greater range.
PLUG IN HYBRID VEHICLES (PHEVs)
PHEVs are part battery electric and part conventional car in that they have a large capacity battery and a small petrol engine. They are plugged into mains power to charge the batteries, and use fuel to power the engine only when conditions demand ie. under load or when battery power is depleted. Some types of PHEVs are also called extended-range electric vehicle and have a small generator to act as back up when the battery is depleted. They have limited range under electric motor only but can manage long distances on one tank of fuel.
HYBRID ELECTRIC VEHICLES
These vehicles combine a conventional internal combustion engine (ICE) with an electric propulsion system but do not need to be plugged in. Typically they will be driven at slow speed in electric mode and automatically convert to the combustion engine when under load. Modern hybrids have regenerative braking and stop start systems, whereby the engine stops when the vehicle is idling. For drivers without a driveway and access to a plug socket, this may be the only feasible option until more charging options are available in Guernsey.
HYDROGEN FUEL CELL VEHICLES
Similar to a battery electric car, a fuel cell car dispenses with the internal combustion engine altogether and avoids any exhaust emissions. Fuel cells are electro-chemical devices that convert the energy stored in chemical form directly into electrical energy, water and heat. This electrical energy is used to drive the electric motors of which there may be one or four, one motor to drive each wheel. Some manufacturers are introducing plugins which are designed for bi fuels ie. for both hydrogen fuel tanks and plug in electrical power.