The electrical grid doesn't only involve many layers of physical infrastructure, it also involves many different actors interacting with each other and with the different parts of the grid. While the physical laws governing electricity are the same everywhere, the human network operating the grid can be very different from one place to another. Yet, in any case, it is this human structure which has to ensure that production equals consumption at all times. In this session, we'll try and underline the most shared features and give a very brief who's who for the grid. What we will present here is a historical and current state of most electrical grids. We will address future grids in the coming sessions. Let's start at the beginning from the point of view of the electricity, producers own or operate power installations, which is almost worldwide now a competitive sector. Producers can be major companies such as EDF and ENGIE in France, or E.ON, RWE, EnBW, and Vattenfall in Germany. Some producers are public undertakings such as ONEE in Morocco. The sector also includes much smaller actors, down to the level of private individuals. The electricity generated in large installations is delivered to the transmission system, which is handled by a TSO or Transmission System Operator. TSOs are directly responsible for the stability of the power grid, and transmission is usually a regulated sector. TSOs can own the grid infrastructure or simply operate them. In Europe, a grid owner should not produce their own electricity to ensure open competition. France has only one single TSO for the whole country, RTE, which is now separated from EDF. In Germany four TSOs share the sector, originating from the four producers mentioned before, but separated from them. These TSOs, together with 40 others collaborate in the European Network of Transmission System Operators for Electricity or ENTSO-E. The situation is a bit different in Morocco, where ONEE not only all owns, but most of the production means, but also operates the transmission system. The electricity flows to the distribution network, which is handled by DNOs, Distribution Network Operators. DNOs are responsible for dispatching the electricity and actually getting it to the end user. In France, the sector is regulated and 95 percent of distribution is ensured by entities. The remaining five percent is performed by 150 local distribution companies. Germany counts almost 900 DNOs. In Morocco, ONEE distributes about 60 percent of the total energy to the end consumers, while some municipalities prefer to deal with distribution by themselves or work with the private company. Finally, the electricity is delivered to the customer from the household to the industrial plant. Now, what we presented here is the usual historical physical structure of the electrical grid. It gives a good picture of the vast majority of existing grids, but we should also mention some deviations from this scheme, which will certainly become more and more important in the coming years. Some very large consumers, such as large factories, are power directly from the transmission system. In France, it's the case for just over 250 customers. Small-scale production and especially decentralized renewable sources are not injected in the transmission system, but directly into the distribution network. An auto-consumption is the direct power transfer from production to consumption. However, unless the customer is completely disconnected from the grid, they will still rely on the electrical system to provide their power whenever their own production is not sufficient. In parallel to these physical exchanges, economic interactions are actually driving the system. Electricity providers are companies with which customers actually sign contracts on the retail market. They are certainly the most familiar actors to many, as they are the ones addressing your electricity bills at the end of the day. They can be major companies owning their own power plants, subsidiary companies from these majors or independent actors. But in any case, providers don't directly provide customers with electricity. They don't control where the electrons reaching their clients originate from. The physical flow of electricity is the interconnected one we discussed before. What retailers actually do is that they purchase the power corresponding to their portfolio on the wholesale market, either over the counter with producers or on trading markets. There's no power trading in Morocco between producers and suppliers however. Finally, the power sector is closely supervised by regulation authorities which have to guarantee equal access to the transmission and distribution networks, and ensure the competitivity works for the better of consumers. In the next sections, we'll see how this scheme might evolve to accommodate more solar and wind energy.
