There are several physical properties unique to electricity that are extremely important to understand. Electricity is a commodity like no other. Understanding these properties will help you to understand why the electricity business operates as it does.
- Electricity cannot be stored in conductors
Electrons cannot be stored in the conductors that transmit electricity from where it is produced to where it is consumed. This means the electrical system must be operated to ensure that supply and demand are continually in balance throughout the system at all times. If electrical supply from generation or storage is not available to match instantaneous electrical demand, the system will crash, resulting in blackouts. Thus an electrical system requires continual surveillance and adjustment to ensure supply always matches demand.
- The path of electrical flow is difficult to control
Electrons flow on the path of least resistance. And if the least resistant path is from the transmission line through a wet tree branch to the ground, that’s precisely where the electricity will flow. Similarly, if this is from one utility’s transmission system into another interconnected utility’s transmission system, that is where electrons will travel. Thus all utilities on an interconnected system must cooperate in operating their systems as the action of one may cause electrons to flow into or out of the others’ systems.
- Disturbances travel very quickly and are hard to contain
Changes in voltage or frequency on electrical lines move at the speed of light, which is 984 million feet (300 million meters) per second. So any disturbance — say a sudden burst of high voltage or a frequency that is out of tolerances — also travels very quickly. This is why a tree hitting a power line in Oregon can quickly result (and has) in lights going out in Los Angeles. This means that not only must system operators cooperate, but they must also be prepared to react to one another’s actions (and problems) almost instantly.
- Outages and significant voltage or frequency fluctuations are not acceptable
With the advent of modern electric controls and microchip-based devices, our consumption of electricity no longer tolerates momentary outages or excessive fluctuations in voltage or frequency. Thus the entities responsible for designing, constructing, and operating the transmission and distribution system must ensure that the system is capable of providing almost continual high quality power.
These properties not only necessitate a centralized coordinating function called system operations, they also create business complexities unlike any other business in the world today.