January 19, 2018
Dear City Council:
Did you know that research in the New York Times reports that New York City alone uses 60 percent of electrical power created in New York State? New York City must find ways to use clean, renewable energy sources to power up this city. For many years, engineers have looked for renewable energy sources such as wind turbines and solar energy to create and store energy. However, in places such as this city weather patterns are not steady. The New York Times reports that the use of renewable energy accounts for only one-fourth of the electricity produced in New York City. This city has to think of other renewable energy sources that do not rely on the weather. Therefore, I believe that we should consider using other “green” methods of creating and storing electricity to power up parts of New York City. One solution to finding a renewable or green energy source is using Piezoelectricity.
In 1880 Jacques and Pierre Curie discovered the piezoelectric effect. This is when piezoelectric materials such as quartz, salt, topaz, and sugar turn pressure and vibrations into electricity. For example, if you step or put force on the crystals in a piezoelectric pad you will create a negative electrical charge. When you release the pressure or the vibrations stop it will create electric voltage. This voltage can be stored in a battery. The electrical charge stored in the battery can be used to power up lights and equipment. Engineers have used piezoelectric technology to make electricity by placing these devices in shoes to use the force of a footstep to create and store energy to charge small electronics like cell phones. Other uses have included igniting a cigarette lighter or a stove, toys, or even dance floors.
Now that you know how this works, you might ask, “How can it help create renewable electrical energy in New York City?” Well, I think that electrical engineers can use this piezoelectric material to design pads that can be used in places that a lot of people can walk on top of these pads and create a lot of vibrations. The perfect place would be the NYC subway system. Engineers can use these piezoelectric crystals to be placed in pads. These pads that are made of piezoelectric crystals are placed them under the concrete of stairways and platforms in subway stations. According to the MTA, currently subway stations receive their power from power plants. Subway stations receive as much as 27,000 volts that are used in the subway station. The third rail uses 635 volts to operate trains.
According to the MTA in 2016 subway ridership on an average weekday was 5,655,755. In one year 1,756,814, 800 total people use the subway system. We know that some subways are busier than others. Subway stations such as Times Square have 64,531,511 riders each year and Grand Central Station has 46,121,501 which means that people walking up and down the stairs and on the platform can create pressure on these pads. The pressure or force created from each person’s footsteps on the piezoelectric pads can create electricity. Also the vibrations from the trains rolling in out of the station can create electricity. This electricity can be stored in a capacitor. A capacitor is a device that stores energy like a battery. This stored energy can be used to power up the lights and equipment in subway stations. For example, the electricity can be used to power the train signals, lightening, machines that collect fares and metro card machines.
The advantages of using piezoelectric are that they are renewable, they do not cause pollution and is requires very little to maintain. The pads can be made and placed under the stairs and platforms easily. There are no harmful health risks to anyone that steps on the crystal pads. The cost of creating the pads is not a lot since the crystals comes from many different types of materials. The pads are connected to wires that allow the voltage to travel to a battery that holds the electricity. However, there are many challenges that engineers might face in using the piezoelectric pads. One major challenge is that each crystal can only produce only a millivolt. This means that in order for the piezoelectric pads to create enough energy to power a subway station than there would have to be enough pads and enough people and enough vibrations from trains coming and leaving the station.
According to Heilman Hackatronics on YouTube, he calculated that one step creates 92.5 MicroJules and that you would need 182 million steps to charge one cell phone. However, engineers might have to figure out a way to place the pads in a way that would capture the most amounts of steps in an area or capture the most vibration each square inch of the subway station stairways or platforms. The placement of the pads can help capture the most amount of electricity. A second major problem that engineers might face is that when the subway is not as crowded, such as nighttime or weekends. There will be less people applying force to the pads and less trains that come in and out of the station. Their will not be as much vibrations or force on the pads to create enough electricity to supply power. This would create a dangerous situation the people in the station as well as trains. Engineers would have to develop systems to supercharge the crystals to produce more electricity with a smaller amount of force or vibration.
Piezoelectricity has been around for many years. We can use piezoelectricity to produce renewable and safe energy. If these piezoelectric pads can work in areas such as subway stations, then we can use them under roads and streets to power traffic lights on streets. Shopping centers can use them as another power source. I believe that we should consider using other “green” methods of creating and storing electricity to power up parts of New York City. One solution to finding a renewable or green energy source is using Piezoelectricity
Very Truly Yours,
A Concerned Citizen
References:
MTA website. http://web.mta.info/nyct/facts/ridership. Webpage reviewed January 18, 2018.
Future Tech. 8 Unbelieve Ways to Generate Electicity by Gavin Philps. Published January 25th 2015. https://www.makeuseof.com/tag/8-unbelievable-new-ways-generating-electricity/. Webpage reviewed on January 18, 2018.
Piezoelectricity & Its Applications. Tariq Tauheed, Graduate Intern at Tata Steel Europe. Published November 1, 2013. https://www.slideshare.net/iamaproudindian/44-azeem. Webpage reviewed January 18, 2018.
Applied Piezo.com. Short history of piezoelectricity. Author unknown. http://applied-piezo.com/short- history-of-piezoelectricity/ Webpage reviewed January 18, 2018.
Piezoelectric Generator. Author is Ludic Science . published September 13, 2014. https://www.youtube.com/watch?v=ACsy6xSIBm8 Webpage reviewed January 19, 2018.
Power from walking Piezoelectric energy. Author is Heilman Hackatronics. Published Nov. 6, 2013. https://www.youtube.com/watch?v=ZWaCnODSBfM. Reviewed on January 20, 2018.
New York Times. How New York gets its Electricity. New York Times. https://www.nytimes.com/interactive/2017/02/10/nyregion/how-new-york-city-gets-its-electricity-power-grid.html Reviewed December 22, 2017.