When you look at the discussions in ENERGY-101 you realize that an understanding of the fundamentals of what electricity is all about really is helpful and may even give you some insights as to what it’s all about.
Well the history of electricity starts with discoveries that were made in the 18th and 19th centuries. One form of electricity that was most apparent to everybody was static electricity, which, is an inherent property of nearly every object. The lose electrons, atoms and molecules tend to migrate to the surface and collect. Often times they’ll be found on a point such as your finger or Harry Potters wand
if you will.
We build those charges up when we pull our sweater off and our hair goes sprong. But inherently it was very difficult to capture and put to use that static electricity. Lightning is probably the most spectacular form of static electricity. We probably all have that image of Ben Franklin with his kite standing in a thunderstorm trying to capture that energy. The truth of the matter is he and most of the other scientist at that point were struggling with that. He fortunately developed the lightning rod which got it to ground…saved a lot of barns and church steeples from destruction but it wasn’t until two Italian’s developed the first battery.
A battery is generally dissimilar metals, let’s say copper and zinc that a separated with an electrolyte. The earliest ones used a brine or pickle juice. The ions migrated; they naturally want to migrate from one metal to the other, from the copper to the zinc. When you put them together in a battery then you have two poles at either end. If you interconnect those with a light bulb in between it, you have the first flow or direct current.
Once we have the battery hooked into a circuit we can look at how we measure what’s going on.
Two primary components are voltage and amperage. Voltage is how exited those electrons are that want to get through the circuit. Amperage is a measure of the flow of those electrons past any given point per unit of time.
One way to think about it is the number of electrons that are flowing down the wire. This is analogous to the way they looked at it back in the days when water was a significant source of power, the waterfall is a great example. The height of the waterfall is analogous to the voltage, how excited are the electrons? The amount of water going over the edge is equivalent to the amperage, the number of electrons that go past a point at any given unit of time. The product of those two, the voltage times the amperage, is power and the unit of measure is a watt.
A watt is a very small unit of power and when we use it in our house we generally measure it in thousands of watts or kilowatt. That particular watt or kilowatt, that power, is the same that we get when we perform work at a given rate or when we consume energy at a given rate. There is a connection not only between the electricity but also to what going on in production and consumption of energy and other mechanical items such as your car or even physically what you are doing.
In recap, voltage is the charge and its desire to get to and balance out with an other charge or an other body. So from this battery, what is the likelihood that the electrons want to go from post to post? Amperage, if you put this in a circuit with like a light bulb or a motor, is want is the rate those electrons are moving across there. And the product of those two, how excited they are and how many are moving at a given rate of time is power and again that’s measured in watts.
Typically, when we buy for our house and plug it into the wall we measure in kilowatts which is just a thousand watts. That same production of power, that use of energy is the same units and concepts that we have when we use mechanical equipment such as our lawnmower, drive our cars or even eat food curiously enough.