Our science class this past week was lucky enough to given the opportunity to listen to Prof Tom Vales of the engineering department tell us about different ways to generate power that have surprisingly been around for centuries, and even more surprising are still used to day.

The first example he gave us was the Peltier effect.

A small portion of history first (as always): This was named after French Physicist, Jean-Charles Peltier. He was born in France in 1785, and his most famous contribution to this day remains the Peltier effect.

The process of it is very simple. Peltier realized that if he ran the electric current through two different metals, he could create electricity. This is how he physically demonstrated it to us. Using a fan with two separate legs (each having a different metal), he placed each side into a cup of water, one hot and one cold. This caused an electric current to flow, and the fan began to spin. This type of effect is used today to heat or cool drinks, a mini fridge. Unfortunately, it only has 10% efficiency, making it impractical on the large scale.

 

Jean-Charles Peltier

 

The next engine displayed on a small scale was the Stirling engine. It was invented in 1816, by Robert Stirling. Stirling was of Scottish descent from a large family. He initially studied Ministry at the University of Edinburgh and became a minister for the Church of Scotland. He was always interesting in engineering and to this day his most famous discoveries continues to be the Stirling Engine.

It is similar to the steam engine but less dangerous and more efficient, with up to 60% efficiency. The Stirling Engine, unlike the steam engine is very quiet and runs off hot water and hot air, the moving air moves the engine up and down, creating energy. The only stipulation was that there had to be a 4degree celsius difference between the water and the air.

Here’s a very basic picture of a handheld Stirling Engine. One of their main advantages is that they have the compatibility to be used as heaters during the winter and coolers during the summer.

 

 

 

The next type that was shown to us was a simple barbecue lighter, an invention that we today take for granted: the Barbecue Lighter. The concept used in the everyday barbecue lighter does a lot more than we probably realized. It

went from a mechanical to electric light, with a small piece of quartz as a spark mechanism. This same type of concept is used in many everyday appliances from everything to lawn mowers to radio frequencies.

All of these concepts he showed us were extremely logical, once we had been exposed to the idea. Even though most had been invented centuries ago, they are still the basis of many new advancements in technology.

 

The final part of his presentation was probably the most exciting, and the part I understood the least. Coming from the Serbian-American Nikola Tesla, was the Alternating Current Power System.

Here is the handsome Tesla. He was the first one to introduce the idea of wireless electricity into homes. Tom Vales demonstrated this one as well. Tesla’s idea in a modern form consisted of a bucket with coils of special coated wire around it that once a current was put through it, produced enough energy to light up a light. We turned off the light, and Tom Vales held a stick that began glowing in two different colors, because it was filled with Argon gas. He demonstrated the same process with a light bulb, even allowing the electric current to run through his body.

Tesla’s idea was to make one of these available in every household, the only problem is that the range was too short, and to power an entire house a large amount of energy would be  needed, at a potentially dangerous voltage.

 

The entire presentation was very enlightening and it was interesting to see these complex ideas on a small and understandable scale.