Hybrid cars are probably the most popular type of alternatively fuelled vehicle available at the moment – the Toyota Prius being a well known early adopter of this technology, with most manufacturers now offering a hybrid vehicle as part of their fleet.
The use of a petrol or diesel (combustion) engine coupled with an electric motor create the “hybrid”, and an on-board computer decides when is best to use the combustion engine and when is best to use the electrical motor.
Generally, hybrid vehicles achieve better fuel economy and lower emissions than standard petrol or diesel vehicles by recapturing and storing kinetic energy normally wasted during movement and braking and shutting down the combustion engine during lower speed driving.
Most manufacturers see the hybrid as one of the key technologies in the future of motoring, and with the longevity and reliability of batteries improving all the time the popularity of hybrids is set to continue to rise.
An Electric Vehicle (EV) is one which uses purely electric motors, most commonly powered by re-chargeable battery packs in the vehicle, rather than an internal combustion engine.
It is worth noting that vehicles using a mix of electric power alongside another type of engine are known as Hybrids, and are hence not considered a pure EV.
Environmental benefits and cost of motoring are the two main reasons for the electric cars popularity, particularly in densely populated urban areas such as London. Relatively low recharging costs, as well as a “zero-emissions-at-tailpipe” are extremely attractive when only short journeys are needed. Criticisms have been levelled at the electric car, as it does contribute to general CO2 emissions, as it uses electricity which has to be produced in power stations. However, if recharging of electric vehicles could wholesale happen during the night when demand for electricity is at its lowest, there would be more of an even demand for power, and hence power stations could operate more efficiently.
Undoubtedly reduced performance whilst driving, a lack of “range” between recharges, coupled with the fact that to improve “range” as much as possible, design of electric cars focuses on reducing its weight down as much as possible, which means many non-essential safety features, such as side impact bars and airbags, are not included, mean the electric car industry has some way to go before they convince the public en-mass to ditch their current combustion engine cars.
Having said that, it is clear the electric motor, whether in hybrid form or pure EV, is one of the key technologies in the future of the motor car, and as battery technology improves, and a network of re-charging points begins to develop, it will become is hard to justify any other type of vehicle for the city driver.
Biofuel, most predominantly available as Bioethanol (for use in petrol engines) or Biodiesel, offer significantly improved environmental benefits over conventional fossil fuels, as well as having similar performance figures (sometimes even better).
Biofuels are derived from recently dead biological materials, such as plants, with Bioethanol produced from plants high in sugar (sugar cane) or starch (corn/maize) and Biodiesel made from plants that contain high amounts of vegetable oil, such as oil palm, soya bean etc. Normal petrol and diesel, by contrast, are derived from long dead (millions of years) biological material (hence the term “fossil fuels”).
Whilst Biofuels do create CO2 when being burned, they are more environmentally friendly because they are made from plants which have just recently taken CO2 from the atmosphere, whereas fossil fuels return carbon into the atmosphere which has been stored beneath the surface for millions of years – hence Biofuels mean there is no net increase in the amount of CO2 in the atmosphere.
Whilst appearing to be an excellent alternative to conventional diesel and petrol, Biofuels have their drawbacks. Their lack of availability on UK forecourts has given way to more serious environmental concerns that demand for Biofuels is increasing deforestation (to create space to grow crops to produce the fuels) – which can create a net carbon-negative effect. In addition, as demand for crops for biofuels rises, this puts an upward pressure on the price of foods such as corn and maize, which adversely affect some of the world’s poorest communities. Debates rage as to the level or significance of these issues, but they are issues all the same.
Still interested in running your car using Biofuels? The good news is Biodiesel can be used in most modern diesel engines cars whereas Bioethanol, most commonly seen on petrol station forecourts as E85 (an 85% Bioethanol and 15% Petrol mix), can only be used on specially modified cars.
LPG, or Liquefied Petroleum Gas, is a mixture of hydrocarbon gases and in vehicles is most commonly found as a bi-fuel (i.e. the car can run on either petrol or LPG – a switch on the dashboard meaning you can change between the two). LPG can be added to an existing vehicle via a conversion and the main advantages of LPG over conventional petrol are that it is significantly cheaper (around half the price of petrol), it is more environmentally friendly as it burns cleaner (this also reduces wear and tear on the engine) and there are no significant differences in an LPG vehicles’ performance.
However, before we all rush out to purchase an LPG conversion, it is worth considering the drawbacks. These mainly centre on the fact that although the fuel is significantly cheaper than petrol, since LPG fuel burns quicker and therefore is less economical than petrol, the real benefits are closer to a 30% saving, rather than the 50% price difference described above.
In addition, as the car needs two fuel tanks, this increases weight, further reducing fuel economy and environmental benefits, as well as meaning less space in your boot, as often that is the only place to put the additional tank.
Furthermore, as petrol engines have become more efficient over recent years, coupled with the end of the Powershift Grant which offered government grants towards the purchase of a new vehicle running on LPG, demand for LPG cars has fallen and most manufacturers have moved away from producing new cars with this fuel.
Surprisingly perhaps, there are a lot of LPG cars on the UK’s roads, with availability of LPG on the UK’s forecourts relatively good. Around 10% of UK forecourts stock the fuel – which generally means there is a station with LPG at the pumps relatively close by most people.
Unlike fossil fuels and biofuels, Hydrogen does not occur naturally on earth and hence is not an energy source, rather it is an energy carrier, much like a battery. Almost all Hydrogen is made from methane and many car manufacturers are currently researching and trialling models which use the hydrogen fuel cell as their primary source of power and we wait to see how these trials progress and what the future holds.