Cars - although they've been with for just about a century, they have radically transformed the lifestyle of pace of the whole planet. People can now travel greater distances and experience a higher level of indipendence. But what if suddenly, cars were to be no longer? This question has arised following first the continuous depletion of our fuel resources, and now, it is greatly emphasised by global warming and emission control. Over the past decade there have been substancial developments in alternative power technologies for mobile vehicles. In this article we will go through the different forms of technologies, their pros and cons, and how does the future look for all of them.

Hybrid Technology
Hybrid vehicles have been around for quite a few years. Most of them function by having a standard fuel engine (diesel or petrol), and then a battery pack paired with electric motors on each wheel. Energy is created by the main fuel engine, however part of it is harvested in the battery packs and energy from braking, going down hills is also stored there. These vehicles however, are just a transitory technology, in what main energy will in the future be derived probably from Hydrogen or Bio-Fuels. Hybrid vehicles are becoming more popular. The only drawback is the increase in premium that a buyer must pay for the vehicle, although price difference is decreasing as the technology evolves.

Fully Electric Cars
Fully electric cars have been around also for a few years, but have had a very poor penetration typically because of the excess weight taken by the batteries since they have to deliver all the power for the car, their low speed (not more than 80kmph in most cases) and poor milage (about 100-150km) covered per charge. Additionally, charging times vary from 8 to 12 hours, which can be an inconvenient. Finally, charging could only happen at home, and thus the car's niche market was limited to urban usage. However, things are changing fast. Lately, sports cars are being constructed as fully electric cars. With new battery technologies, which deliver lighter and more power batteries, new cars are being constructed which can acheive speeds in excess of 200kmph, have a distance autonomy of over 300km (and this will increase at a steady 35-50% rate each year), and best of all, can achieve a 95% charge from flat in 8 minutes! Charging points for the cars are being installed in several fuel stations and parking areas. This is definitely a technology that will be extremely popular in the following decade.

Solar Powered Cars
Solar Power - more specifically photovoltaic technology - has been around for the past 40 years or so. Concept cars powered by solar energy have been around for over a decade, however none has made it to the production line, mainly for one simple reason - solar energy harvesting technology is not powerful enough to drive a car. Even though prospectives for the technology are bright, and in a couple of decades can reach a level where solar energy on its own will be enough to power a vehicle decently, the future of this technology lies mainly in the integration of the photovoltaic cells with fully electric cars or hybrid cars, which will help in charging the battery when the car is in direct sunlight, and thus reduce on the base charging time/bill.

Hydrogen Powered Cars
Hydrogen is definitely the power of the future. Featuring zero carbon emissions (combustion produces just water vapour), and can be utilized via fuel-cell technology, which has no moving parts and is extremely more energy efficient than internal combusion engines. Hydrogen can be produced by electrolysis of water, and is therefore potentially widely and unlimitedly available. The only drawback of hydrogen is that is a very low density gas, and cannot be converted to a liquid at room temperature. However, new technologies for "packing" larger amounts of hydrogen in tighter space at reduced pressures are being developed, using complex carbon arrays, that have increased the density by a six-fold over previous technologies. Hydrogen will find its place on the market in hydrogen-electric hybrid cars. Some manufacturers are already planning to produce in series hyrdogen-electric hybrid vehicles.

Bio Fuels
Bio Fuels such as Bio-Ethanol and Bio-Diesel are chemical compounds similar to the crude-oil derived counterparts, but derived from crops and fruits grown commercially. These are being considered as the transition fuel on the way to Hydrogen, as they are easier to produce, and most car engines operate on them. The future of bio fuels lies mainly in aviation and marine industry, as, especially in the case of aviation, no alternative technology known till now can store enough energy in a low mass as to move air planes over large distances carrying heavy loads.

Methane
Methane is a gas derived from a variety of natural and industrial processes. It is cheap to manufacture and distribute. The only problem it has for integration into cars is that it requires very heavy containers so as to carry it around, not as much as hydrogen though. It can also power a fuel cell. Methane will probably assist in the transition of vehicles from liquid fuels to hydrogen. It is also the gas of choice that will power a number of mobile devices in the future.

As it is apparent, the auto industry is moving towards greener energies, and at the same time not compromising performance as we know it today. Obviously, cars will tend to get lighter, and SUV's have a very grim future ahead. Nonetheless, technology is progressing at an amazing pace, and it can safely be stated that the transition from liquid carbon based fuels, to clean, non-carbon based technologies in the automotive industry has started.