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What is the ESC?

What is the Electricity Supply Chain and how does it differ from the electricity system?
In this activity, we will see together what the electricity supply chain is. But before starting, let me make clear the differences between the electricity supply chain and the electricity system. The electricity supply chain is the set of all relationships that occur among the agents, the players that interact to produce and deliver electricity. The electricity system is the set of all the devices, the equipment that are needed to physically deliver electricity to consumers. Therefore, the agents that interact in the electricity supply chain make use of the electricity system. The electricity supply chain is represented in this slide here. It is composed of the following activities– production, transmission, distribution, metering, and retailing, and finally, dispatching.
In the upper part of this slide here, we see the production plants. They are the industrial installations that are needed to produce electricity. How do they do so? They convert primary energy sources into electricity. Plants can be huge, like hydro-power plants that convert the kinetic energy of falling water into electricity, or nuclear power plants that convert the potential energy contained in the nucleus of uranium into electricity. Or as small as a tiny photo-voltaic panel that converts the sun that comes from the light into electricity. But they are all connected to the electricity grid as it is represented here. The grid transmits electricity from producers to the users.
It is drawn here as these big, bold, thick line that represent the transmission line or, better saying, lines since typically there are several transmission lines that altogether allow electricity to be delivered from production, from the power plants to the users. The main feature of the transmission lines is that transmission occurs at high voltage. And the reason is because in this way it can be optimised the use of the mean through which the electron flows. But remember, voltage is the electricity pressure. We use electricity at our homes at a low voltage. Therefore, voltage is down-scaled when electricity is then transmitted to the end consumers.
The lines that transmit electricity from the high voltage of transmission to the end consumers are called distribution lines. At distribution lines, transmission occur at low voltage. We see here at presented also the load. Remember, those who use electricity that are typically connected at low voltage, even though some large users, those who use a lot of power, can be directly connected at high voltage. When electricity is distributed, which means delivered to end consumers, the amount of energy that end consumers use need to be measured. This is called metering. The activity of selling energy to end consumers is called retailing. Finally, we see represented here the activity of dispatching. Dispatching means maintaining the electricity system under control.
The entity, the body that does dispatching is called system operator. The system operator makes sure that production follows the load. Whenever load changes, it rises or reduces, production has to follow accordingly. And the decision on who has to produce and what it is taken by the dispatcher. It does so by making sure that power is synchronised as it is for transmission lines of modern systems, all the systems that we know as users. And making sure the voltage remains within the predetermined limits.

Preview of Week 2

For Week 2, we shall see how the electricity industry works and how it is economically organized.

We shall first describe the Electricity Supply Chain, and the way electricity production and exchange can be economically organized. Then we will discuss the timeline of the electricity industry, and how the exchanges of electricity are settled. We shall end up with a discussion about how the electricity industry works in your own country.

Let’s Begin

To start off our second week, let’s ask the question: What is the Electricity Supply Chain and how does it differ from the electricity system?

In this video, you’ll learn more about the Electricity Supply Chain (ESC) and its five functions or activities, namely:

  • production
  • transmission
  • distribution
  • metering and retailing
  • dispatching

We’ll delve into the kinds of power plants, how electricity is transmitted from these sources to our homes, and how power is sustained and controlled.

Feel free to share your insights and key takeaways in the comments section.
(The scheme used in the video can be found in the Downloads section)
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Electrical Industry: Production and Economics

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