How do we optimise and secure power grids?

"Safely managing energy flows is a real issue of our times," explains Eric Cahuet, director of the Engie Ineo power transmission unit (SCLE SFE)

Solar photovoltaic, low and high temperature solar thermal, hydroelectric, geothermal, biogas and biofuels, wind power: the sustained development of renewable energy sources inevitably brings about changes in how power grids are managed. How do you anticipate an unexpected inflow of local energy production? The key is in the intelligence of future grids. ENGIE Ineo is closely involved in these famous smart grids through the Arkens solution, which helps protect power grids. A closer look with Eric Cahuet.

Today in France, what developments are energy operators faced with?

We estimate that in 2030, almost 50 % of all power production will involve renewable energy sources! This is excellent news and enables us to foresee sustainable, decarbonised and environmentally-sound growth in line with the ENGIE Group’s commitments. However, the massive influx of intermittent power supplies on transmission grids disrupts their topology and introduces certain technical difficulties that we must deal with rapidly.

Firstly, the fact that renewable energy production is decentralised impacts the operation of existing grids, which are designed to transmit power in a single direction. The flows now need to be multi-directional, which complicates our interventions in the event of an incident.
Furthermore, the distribution grid protection systems, primarily based on phase overcurrent protection, must now include short-circuit current forms, directions and levels that are different from those generated by classic synchronous machines.

Then, renewable energy sources are intermittent; their production depends on the source (solar, wind) and cannot be controlled (without additional storage). These sources do not currently participate in the primary frequency regulation, which means that in case of an incident on a production unit, they do not contribute to the automatic load balancing mechanism on production units in service.

So, the specific nature of these renewable energies implies that we now need efficient and suitable responses from grid operators to enable the transmission system to integrate and manage these new forms of decentralised and intermittent production. A real challenge!

How can we adapt grid management to these structural changes?

This is the whole question of grid flexibility, which implies the use an analysis of data flows. Previously, low-speed communication networks could only report partial information on events occurring on power grids. Now, substations have broadband interconnections and act as communication nodes, to connect data networks and power grids. Using information and communication technologies, Smart Grids enable us to better integrate decentralised production to guarantee system quality and stability.

The Arkens solution stands as a core component in future grids through the use of digital technology, which enables us to benefit from distributed intelligence. We have imagined and designed a range of computer systems with advanced digital architectures, integrating innovative, high-performance, safe and interoperable algorithms. They analyse power grid data in real-time and control the electronic systems protecting installations, while reporting data to our client information systems. The result: a balanced, available power supply is assured for consumers.

What specialist expertise does ENGIE Ineo bring to grid operators?

We contribute to the safety and protection of power grids through our Arkens solution. We are also working on real-time monitoring of networks using digital technology: one of the primary issues for the future for transmission system operators in France.
Our internal experts working on algorithms, modelling power grids, designing hardware and software, cyber security and communication networks enable to produce tailor-made solutions that are scalable and sustainable, with algorithms specific to the needs of each client.

For example, for island grids, we designed an algorithm that secures load-shedding and limits the risks of grid outages. An essential development as certain events can cause a partial or total grid outage! This is why at ENGIE Ineo we work with each client to co-build an algorithm to best suit the needs of the end user.

The intelligence of future grids is actuated, energy flows can now be managed, and power grids optimised and operated securely.