Finding new ways to produce renewable, cheap electricity is critical to our future. My study on gravitational energy serves the purpose of spreading the knowledge of how gravity can serve this purpose. To do this, I built a gravity powered generator, using a combination of readily available materials and piecing together the few designs I discovered, that can produce light when a weight is dropped. 

I started heavy research into how gravity was already being used in the energy industry. A great example of this is Energy Vault building a 75 meter tall tower to show the possibilities of using gravity powered energy as a more reliable renewable energy source. They let 35-ton concrete blocks drop for about 30 seconds in order to generate a megawatt of electricity for homes around the area. The CEO of Energy Vault says that this could be a great way to store energy through gravitational potential energy, as lithium-ion batteries degrade over time. I was captivated at the opportunities that these generators could bring, so I decided to create and test the efficiency of my own Gravity Powered Generator.

My design consists of two bicycle wheels on a wooden base, one with the tire and the other without, on stands linked with chains from the stripped tire to the sprocket of the other. To demonstrate the creation of electricity, a dynamo with an LED light is attached to the edge of the wheel with the tire. A chain links the sprocket on this wheel to the outside of the stripped wheel, creating a huge mechanical advantage. When there is enough load connected to the chain, the whole mechanism spins, and the LED light illuminates. 

To complete this, I cut the back wheel off of two disposed bikes because only the back wheels have the correct stands to secure them vertically. Then, I used mounting brackets and screws to secure both wheels to the wooden base, slightly offsetting them so the chain has a smooth and parallel path from one sprocket to the outer wheel. Finally, I rigged up a clamp to one of the wheel supports that attached to the dynamo in a position that allowed it to spin tenfold when the output wheel spun.

I put different weights off the end of my mechanism, let them fall, and recorded the time that the light bulb illuminated. I analyzed the data I collected by separating the weights that produced light and those that did not, like 15 pounds or less. I saw that as the weight grew heavier, the time that the LED was illuminated decreased. This was expected, because heavier weights exert more force on the chain, making the wheel spin faster. A large outlier in the graph is the test for 17 pounds, which proves it to be the most effective weight. As you see in the data graph, there is an exponential increase in the time the LED was illuminated as the weight decreased constantly. The time doubled going from 26 to 22 pounds, then basically tripled again going from 22 to 17 pounds. I expected there to be a constant rate that the time increases as the weight decreases similarly. My mechanism also sat out in the cold for a couple of weeks, so the chains and sprockets might have rusted slightly, limiting the motion of the mechanism.