Electric power transmission is basically the same thing as electricity distribution. These are just two terms that describe the exact same thing. Power plants are basically generating energy and then move it to substations. Then, electricity reaches the household.
In North America, there are practically three major grids: ERCOT, Eastern Interconnection and Western Interconnection. Electricity is practically supplied to the entire continent through these three power grids. Obviously, many other companies are involved in the process, like Lindsey Manufacturing in the creation of what is used to distribute electricity.
High voltage line construction has a pretty long history. All throughout it we had distribution lines and transmission being offered by the same company. As time passed though, the electricity market became free. We now have different electricity transmission companies that are not distribution companies. Transmission companies normally build the high voltage lines and the distribution companies just work hard to move them to clients.
Because of the evolution of technology, we now have various differences that can be seen when referring to transmission lines and even voltage line construction. We have different AC (alternating current) types that are possible. Usually, these use 3-phase AC. Even so, there is also 1-phase alternating current that can be used, usually what is visible in the electrification systems used by railways. If looking at long distance distribution, submarine power cables will be often used. The high-voltage lines are common for distances that go over 400 miles.
High voltage is nowadays the norm for energy transmission. That is due to the fact that when you use this you end up losing a lot less energy. Long-distance electricity transmission is not without its faults. The longer the distance, the higher the possibility that losses are going to occur!
High voltage line building is all about overhead power lines. Underground power stations were used in the past but now they are not considered as a norm because of the really high associated cost. More manpower is necessary and needed tools are different to build underground transmission and power stations.
To put it as simple as possible, electric power transmission is highly complex. Various companies are nowadays involved in the process and they need to deal with an ever-changing technology. Evolution is constantly happening, with solar power being a great example of something different that might become the norm in the future. However, even with solar power we do need to have a way to distribute the electricity to households and businesses.
Transmission can be done through various methods but the common approach is to use the high voltage lines. They are very useful and will generally be preferred over the underground transmission methods because of costs. For households it is important that costs are low. Distribution companies have to adapt and need to use distribution methods that are effective. The biggest problem is usually that losses occur during transport but losses can happen in many other situations. Electric power transportation is a part of our daily lives that we rarely look at but that does influence us.