The increasing demand for electricity and limited supply of fuel calls for the need of alternative sources of energy. Through this project, we display a method to light up the street lights and suburbs close to highways by extracting the impulse energy on the speed bumps by the automobiles.

This mechanism converts the impulse energy produced by the passing of the vehicle over a speed bump into the linear motion of the rack, attached to the speed breaker, which drives a pinion mounted on shaft with the help of one way bearing. The shaft rotates only in the locking direction of the bearing, which in turn rotates the pulley mounted on it. The restoring springs push back the speed breakers to their equilibrium state. The pulley drives the alternator rotor through a V-belt. The alternator used is a low inertia compoundly excited DC alternator, that is, it requires batteries to generate field current. The batteries are connected to the alternator, which get charged when the alternator rotor rotates.

The data from the experiments shows that around 8 Volts are generated when a vehicle moves over the speed breakers at a speed of 10kmph. The voltage generated decreases as the speed increases and weight of the vehicle decreases.

Considering the average Indian traffic density to be 18 vehicles/km (reference The World Bank), excluding two-wheelers, moving with a speed of 5m/s on the speed breaker. 5MWh of energy can be produced in a year from a stretch of 200 mt. of speed breakers. This number is bound to increase two-fold if we consider the two wheelers.

Calculations:
The output of the alternator used is 36 W. Consider a 10 mt. span of speed breakers, time taken by the vehicle to cross the speed breaker is 2 sec.
The total no. of vehicles passing over the speed breakers in an hour is 330. Therefore, energy produced in one hour = Power * Time * No. of vehicles
Hence, energy produced in an hour = 36*2*330 = 23.76KJ
Therefore, energy produced in one year = 23.76*24*365 = 208.137 MJ

The material chosen for manufacturing shaft is glass reinforced dimethyl polyacrylate.(a composite)

The springs are made of steel springs or phosphor bronze. The material chosen for manufacturing gears was Nylatron NMC ( a polymer, which is self lubricating and wear resistant).

A Zero emission alternative energy source that harvests wasted kinetic energy to produce substantial amounts of electricity all round the year.According to Performance Review of Thermal Power Stations 2006-07, 0.7 kg/KWh of coal was consumed. A 200 mt. stretch of these speed breakers is enough to save 9500 kgs of coal in a year. Villages and fields/farms close to the installation; where the government is unable to supply electricity in the required amount; can be powered in a cost efficient way. Street Lamps can be lighted during the night using this energy.