International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056 Volume: 05 Issue: 02 | Feb-2018 www.irjet.net p-ISSN: 2395-0072 © 2018, IRJET | Impact Factor value: 6.171 | ISO 9001:2008 Certified Journal | Page 1612 Energy Harvesting from Road Pavement: A Cleaner and Greener Alternative A.Shukla *1 , S.A. Ansari *1 *1 B.Tech Ⅲ year Student, Zakir Husain College of Engineering and Technology, Aligarh Muslim University, Aligarh, Uttar Pradesh, India. ------------------------------------------------------------------------***------------------------------------------------------------------------- Abstract: The energy demand has consistently been snowballing worldwide and with depleting reserves of fossil fuel, it is becoming increasingly necessary to develop novel ways to harvest energy from non-conventional sources. Over the last two decades, the emphasis on energy harvesting has increased to the extent that it is being considered as one of the paramount challenges of 21st century. Although energy harvesting is in its nascent state, it has the potential of reducing carbon footprint and dependency on battery power. The procedure of energy harvesting includes capturing, conversion, and storage of energy using efficient devices. The potential ambient sources through which energy can be harvested may include heat and light from the sun, and vibration, weight, and movement of vehicles and pedestrians. Until recently, energy harvesting has been focused on sunlight through photovoltaic cells (PVC). However, due to the dearth of solar energy at night, costly maintenance, and difficulties with glass panels, the attention of researchers is shifting towards piezoelectric and pyroelectric materials. A piezoelectric material utilizes physical pressure and converts it into electrical energy. While a pyroelectric material converts thermal energy into electrical energy due to the charge produced when the temperature of the material is altered as a function of time. These methods have immense potential to become the desirable future energy generating alternatives. Lately, roads have been identified as a promising energy harvesting domains as they are spread over a large area of land, carry high traffic volumes of heavy vehicles, and their temperature may escalate to around 60℃. Majority of energy consumption takes place in urban areas where pavements cover large tracts of land; hence, piezo and pyroelectric devices may be embedded under the pavements, sidewalks, stairwells, etc. As the vehicle or person hit the surface, an electrical charge is produced which can be used for direct supply to nearby devices using transmission lines from a common source point or can be stored through suitable devices such as batteries and capacitors. This study presents a review of technologies being developed worldwide for energy harvesting from pavements, their efficiencies, and prospects to meet future energy demand. It also presents case studies of major projects undertaken globally to harvest energy from pavements. Keywords: Piezo-electric and Pyro-electric Technology, Energy Harvesting, Clean and Green Energy INTRODUCTION: The energy consumption is growing exponentially every year, which in turn increases demand on fossil fuel reserves. Overconsumption of energy has led to the depletion of natural resources and it has been observed that these resources are being consumed at a rate 100,000 times faster than these are being replenished [1]. Also, studies have shown that the fossil fuels, especially oil and gas are expected to get depleted by the end of the 21st century [1]. This is by far the only reason why researchers have been looking for other renewable and green energy alternatives. This made us look for other sustainable and green energy alternatives. It was stated in an IISD report that the G7 countries, a group of finance ministers and central bank governor's agreed to phase out the usage of oil, gas and coal by the end of 2100 [2] .The endeavor for alternative energy sources has also led to the exploration of piezoelectric and pyroelectric technologies. The use of these technologies in pavements and urban roads may create a significant source of energy. Shift to the energy generated by integrated piezo- and pyro-electric pavements from traditional fossil fuels offers a clean, green and sustainable energy harvesting method, which will not only reduce the carbon footprint but will also lead future generations to use a more feasible and reliable source of energy. Piezoelectric devices are used for harvesting energy from external loads under roads, walkways, dance floors, and so on. The applied mechanical stress caused by the wheel loads produces storable electric charge. Piezoelectric technology used in pavement generates electricity by the means of a piezoelectric crystal which are implanted few centimeters below the road surface. Their deformation under the load of traffic produces electric current. Such devices are used by the East Japan Railway Company (under pedestrian subway station gates) and by Innowattech (under roads in Israel), Pavegen, among others. According to Innowattech, if these devices are planted along a one-kilometer stretch of road then it could provide an average of 400 kW of power which is enough to power 162 U.S. homes [3] [4]. This example suggests that piezoelectric energy harvesting is a viable alternative. Observing the beneficial traits of this technology, in 2011 California state assemblyman Mike Gatto proposed Assembly Bill 306 to develop this technology for Californian roads [5] [6].