Professor Tom Vales of the engineering department came by to class to give us a mini presentation accompanied by a series of interesting experiments used to generate energy in a small scale. Many of the “machines” he brought for us to see have been around for centuries and some are still used to this day on a larger scale.
The first contraption he showed us demonstrated the Peltier Effect. It was named after French physicist, Jean-Charles Peltier and to this day, he is most well known for the Peltier effect. Its process is relatively simple by nature. His realization came when he ran the electric current through two different metals and created electricity. Peltier’s original demonstration of this was by using a fan that had two different legs, each made of a different metal and then placing one leg into a cup of cold water and the other into a cup of hot water. The electric current began to flow through this and caused the fan to start spinning. An example of how the Peltier effect is still used today is in car cup holders that are used to either heat or cool drinks. Even though it was effective, its rate of efficiency is only 10% which deems it unreliable.
An example of how the contraption would be built for the Peltier effect
The second contraption Tom Vale showed us that can be used to generate energy on a smaller scale was the Stirling engine. Robert Stirling invented it in 1816 and his most famous discovery is this. In many ways it is close to what the steam engine does but a lot more efficient (up to 60%) and not as dangerous. Its power is generated from hot water and hot air, with the air moving the engine up and down. Although it was somewhat simple in nature and quite efficient, it couldn’t operate unless there was a 4 degree Celsius difference between the water and air being used to run the Stirling engine. However, it can be used as a cooler during hot summer days and a heater during the winter!
Small version of the Stirling Engine
The next experiment contraption he showed us was what’s commonly known as a Barbeque Lighter. It was initially used as a mechanical light but then went on to become electric light and it would only require a small piece of quartz in order to “spark” up the mechanism. The concept of it is still very much used to this day in not only barbeque lighters but even lawn mowers.
The last thing he presented was Alternating Current Power System. It was designed by Serbian-American scientist, Nikola Tesla. He was the first to think of what it would be like to have wireless electricity in homes. Tom Vales demonstrated this with his own contraption based off of Tesla’s idea made up of a bucket with coils of wire around it so that once there was an electrical current moving through it, it would produce enough energy to light up a light bulb. Professor Vale’s demonstration of this was extremely interesting and it seemed dangerous albeit he didn’t appear to be too concerned about it. Once the lights in the classroom were off, we were really able to see how this system worked because he held a fluorescent light that glowed in two different colors since it was filled with Argon gas. The main idea of this concept was to have a machine such as this available in every home but its range wasn’t far enough to be perfectly efficient and it would require a very high level of energy leading to high levels of voltage.
All in all, I found his presentation of the different ways of generating energy to be very informative and I had no idea how something so “simple” could be created on a much larger scale and be so effective.