Energy

Leonardo Hernandez

One of the most fundamental concepts of thermodynamics and one of the most significant

aspects of engineering analysis is energy. After Newton formulated the laws of motion which led to understanding the concepts of kinetic energy, potential energy and work, this laws then led to a broad definition or understanding of the concept of energy. But what is energy? Some say energy is the “ability to do work”. Doing work basically means to move a system, to heat a system, to lift a system, basically to change a systems energy state you have to apply work.

Energy is like the air, it is all around us even if we can’t see it. It is being used in almost every

aspect of our lives. Every time you turn on the lights, while cooking your using energy, even that food you just cooked is a form of energy. Energy powers your car, your air conditioner, your television and the list goes on. There exist many different forms of energy. Some of them are: solar energy, mechanical energy, chemical energy, energy in the form of heat, nuclear energy and magnetic energy, just to name a few.

It is known that matter can be changed into energy and energy into matter but the total amount stays the same. The law of conservation of energy states that energy may neither be created nor destroyed. Therefore the sum of all the energies in the system is a constant. In other words what the law of conservation says is that energy can be transformed from one form to another (e.g. the stored chemical energy in a battery is transformed into electrical energy to power a flashlight) but the amount of said energy will stay the same because energy cannot be destroyed nor created.

The most widely used form of energy since the industrial revolution has been oil (a type of fossil fuel). Oil is refined into petroleum products and those products are the ones that have a daily consumption. Petroleum products include gasoline, diesel fuel and heating oil, liquefied petroleum gas, jet fuel, still gas, asphalt and road oil, naptha for feedstock, lubricants, kerosene waxes and many more. Oil has served its purpose for many decades but has become unsustainable. The world reserves are said to be declining and global warming is also said to have been caused in part from its excessive consumption.

Renewable sources of energy have gained large popularity in recent years as a way to free

ourselves from oil consumption. Renewable sources of energy include solar energy, wing energy, geothermal energy, biomass or bioenergy and hydropower amongst others. The problem encountered with many of these types of energy is that they are not financially viable at the moment. Even though oil is harmful to the environment since it is still more economical than renewable sources then it is still consumed.

In conclusion energy is all around us, from the airplane in which you travel to the light bulb that light up your house. Even when energy cannot be destroyed we still have to cherish the energy sources available to us and also cherish the place it came from (earth). It is in the hands of engineers and scientists to find new and exciting ways in which energy can be used more efficiently and environmentally friendly which will be a very important challenge during our lifetime.

References:

Fundamentals of Engineering Thermodynamics, Michael Moran, 5th edition

Fundamentals of Physics, Halliday, 7th edition

http://library.thinkquest.org/2745/data/lawce1.htm

http://www.youtube.com/watch?v=o_5oYuDY2qM

http://www.energyquest.ca.gov/story/

http://www.eia.gov/energyexplained/index.cfm?page=oil_use