In my first blog post I mentioned that we cannot create energy but we can only change its form into something which is useful for us. Our history of converting forms of energy since the industrial revolution has largely consisted of converting the energy into mechanical energy in the form of a piston engine or a spinning turbine. The early days of this produced many wonderful machines that burned wood or coal which have stored chemical energy. That chemical energy was released in the form of heat (fire), and that fire was used to boil water. The steam produced from this boiling water has a lot of energy because it can be at high pressures. All of the pressure is used to turn a steam piston engine or a steam turbine (a glorified pin wheel). The spinning steam turbine is mechanical energy that we can put to good use. In those early machines the steam pistons would directly drive other equipment such as the paddle on a steam boat or the gears on a steam engine train.
Later on down the road some clever people discovered another form of energy that we could put to good use, and that was electricity. Electricity is a wonderful form of energy and it is used to power a huge portion of our equipment today. The people who were converting energy into mechanical energy also realized how great this electricity thing was and they decided to use the mechanical energy from Steam turbines to spin an electrical generator which would convert the energy into electricity.
Today a large majority of the electricity that we use is generated by a mechanical turbine spinning a generator. We have several different sources of energy that we use to spin these turbines, but at the end of the day they are still just a turbine spinning a generator. A coal power plant spins a turbine/ generator as described above. A nuclear power plant uses chemical energy stored in nuclear material to boil water and spin a turbine/generator. A hydroelectric power plant uses water at a high elevation aka potential energy to spin a turbine/generator. A wind turbine uses the winds kinetic energy to spin a turbine/ generator. I think you see my point, we really haven’t come that far today from where we were a couple hundred years ago.
One approach to thinking of new energy sources for the future is looking for situations that have some potential energy that we can use to spin a turbine/ generator. If you can think of any other potential sources of energy that we can use to spin a generator please leave a comment below.
Photo Credit: http://www.historyinsidepictures.com/siteimages/R9.JPG