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Did you say “smart grid”?

This notion is born from the will to modernize the electrical network. While electrical needs are rising, it seems difficult on a long-term basis to consider completely replacing or reinforcing networks. From now on, it will be necessary to optimize electrical networks with the help of numerical technology.


Since it is connecting producers and consumers, the electrical grid must instantly balance supply and demand while providing a safe and sustainable supply. To cope with the increase in electrical needs (air conditioning, heat pumps, electric cars…) and the emergence of new energy sources that are clean and decentralized but also intermittent and fluctuating (biomass, solar, wind, hydraulic), the grid has to become smart in order to optimize consumption, distribution and production on a local and global scale.

To achieve this mission, electrical grid uses new digital information and communication technologies. Each part of the grid (producer, consumer or distributor, tiny or big) becomes a communicating and interactive item. Through data exchanges, it is possible to create strategies in order to adapt supply and demand in real time.

A new sector is developing with smart grids, requiring various skills: the most obvious are energetic and electro-technical ones, or computing, numerical and environmental skills but also unexpected abilities like psychological ones for analyzing utilization and acceptability of those new devices.

 

Architecture of a smart grid

There are three levels:

  • the physical grid that consists of lines, transformers… to forward and direct energy
  • the communication structure (optical fiber, GRPS, CPL…) to collect and transmit data
  • the application and service level (remote troubleshooting tools, local management of electrical demand…)


Network instrumentalization

Currently, instrumentalization exists only to ensure transport with operational security. Considering the high number of structures, the amount of sensors on the distribution network is low, but adding new electrical sources implies increasing this number. Closer to consumers, smart electricity meters accurately and in real time count the flow of energy exchanged.


The consumer becomes an actor

Nowadays, supply/demand balance is ensured by anticipating electrical consumption with historical and meteorological databases so as to constantly adjust production. The only way to adjust the balance is through production. Smart grids, particularly smart electricity meters, inform consumers, allowing them to become actors in energy management.


From centralized to local management

Formerly, production was centralized and controlled at a national scale: energy sources were only huge power plants. From now on, decentralized producers are linked to the distribution network instead of the transport network. So distribution of electricity should be designed at a local scale and then a national scale.


New storage possibilities

To overcome intermittent and fluctuating production issues, we can store the energy. Storing also helps system empowerment. Many ways to store energy have appeared: from PSH (Pumped-storage hydroelectricity) proving its efficiency for 40 years to more innovative technologies like flywheel, CAES (Compressed air energy storage)… Studies in the field of energy storage are multiplying.


From the electric grid to the energetic grid

The smart grid concept extends to the smart energy grid, mixing electricity, gas, heat and their respective storage.

 

Stéphanie Lescarret, May 2014