By TreeLiving With skyrocketing fuel prices, you often feel forced to think of alternative vehicles. Cars that consume less fuel or are completely based on alternative sources of energy are also environment friendly or eco cars. Hybrid cars and electric cars are popular options that people consider when planning to buy eco cars. Though there are ways to make conventional cars more fuel efficient, the tax rebates offered on eco cars make them an attractive alternative. Hybrid cars use twin sources of energy – a combustible engine with a smaller capacity, and an electric motor. When this eco car is in operation, the low capacity internal combustion engine is always running. In situations where the car has to accelerate or climb steep slopes, the electric motor, powered by a high-capacity battery, gets into action and gives the vehicle the required kinetic energy. The electric motor also powers the car while it is running at a constant speed for a long time, like on a highway, and the combustible engine is switched off. A conventional braking system dispenses the excess energy generated by the combustible engine and converts it into frictional heat. However, unlike conventional cars, the eco friendly hybrid cars, while braking or reducing speed, convert the excess kinetic energy into electricity and store it in the battery. The device that makes this conversion possible is called a regenerative brake. Electric cars run on AC and DC motors and are powered by rechargeable batteries. The sources of power for electric eco cars are rechargeable lead acid, lithium ion or nickel metal hydride batteries connected in series. To power up an electric car, you do not need to go to a gas station. Simply plug it into an electric socket – similar to the way you charge your laptop or cell phone – and it gets recharged for the next drive. The basic difference between these eco cars is that while a hybrid car does derive some of its power from a conventional gasoline engine, an electric car gets all of its power solely from electrical sources. This is why advocates of electric cars consider them to be true eco cars or completely non-polluting zero-emission vehicles. Hybrid and electric cars are certainly more environmentally friendly than conventional cars and can really make a difference on your pocket and the planet.