Energy is the blood of our modern life. To understand what energy is, we need a definition first. In physics, energy is a quantity that can be assigned to every particle, object, and system of objects as a consequence of the state of that particle, object or system of objects.(wikipedia) There are various forms of energies like kinetic, potential, gravitational, sound, thermal, etc. Energy can be transformed from one form to another. That should be it as a definition.
We get energy by burning things(!). As an example, to get kinetic energy like running a car, we burn fossil fuel like gasoline, diesel, petrol, etc. Now we also need to understand what fossil fuel is. Fossil fuels are fuels formed by natural resources such as anaerobic decomposition of buried dead organisms. The age of the organisms and their resulting fossil fuels is typically millions of years, and sometimes exceeds 650 million years. The fossil fuels include coal, petroleum, and natural gas which contain high percentages of carbon.(wikipedia) But fossil fuel is not renewable. Means it can not be renewed or recreated and we are actually burning up the blood of our modern advanced life.At this speed (burning the fossil fuel) we will be in a huge energy crisis in no more than 100 years. Actually the developing countries or so called third world is already in energy crisis. This is the high time to research and start using renewable energy.
