Due to the transition towards renewables, cyber threats and a wide range of energy policies the CESA (Continental Europe Synchronous Area) as the biggest synchronous electricity grid in the world faces new challenges.
Last week the largest synchronized power grid of the world experienced a massive blackout. For half a day all of Spain went dark, as did Portugal and parts of France. What is the system that makes your electric devices at home work and that we all take for granted? Is the next blackout just around the corner?
It is still unclear what led to the massive blackout on the Iberian Peninsula on 28th April. The investigations will still take some time since there is a variety of possible causes. It might be due to a massive fire in Southern France causing the Spanish grid to drop below 48.7 Hz or because the Spanish and other parts of the power grid were out of sync or it might even have been caused by a cyberattack. For me this brought up the question how the European grid actually works, which weaknesses it has and what a potential direction for its future development might look like.[1–4]
The Grid
Originating in 1958 through collaboration between France, Germany and Switzerland, the power grid, or CESA (Continental Europe Synchronous Area), is now the biggest synchronous electricity grid in the world. It covers 32 countries, from Morocco over Germany to Albania and Ukraine. It mostly operates under the umbrella of the European Network of Transmission System Operators for Electricity (ENTSO-E) which also operates other synchronous areas such as the Nordic Synchronous Area (Sweden, Norway, Finland and parts of Denmark).
It supplies 400 to 500 million people with a production capacity of 859 gigawatts (GW) of electricity.
As always for such a large system the numbers are dazzling and the technical precision to keep it alive is astounding.[5]
The fascinating part about the Power Grid is that it operates at exactly 50 Hz, meaning the electrical current switches directions 50 times per second. Such a current is called Alternating Current (AC). That means the electrons in the wires oscillate at this frequency and transmit energy from the power plant, like a big solar plant or a turbine at a hydropower plant. The current at the solar plant has to be transformed from DC (direct, non-alternating current) to AC first via an inverter. The hydropower plant uses a water-powered turbine which is connected to a generator which creates the necessary AC. Such a generator must rotate at a precise speed to generate 50 Hz (E.g., a two-pole generator must spin at 3,000 revolutions per minute [RPM]). The AC transmits energy over long distances at high-voltage up to 400,000 volts via high power cables until it gets gradually stepped down to 230 for at-home appliances and outlets like your toaster.
Problems in the grid
Even small deviations from the frequency, like 49.8 Hz or 50.2 Hz can cause big efficiency losses or even damage sensitive equipment. Such deviations can happen if too much energy (several gigawatts) gets fed into the network or too little is consumed (the frequency increases) or if not enough energy is available or too much energy gets consumed (the frequency decreases). So everything in the network has to function like clockwork and needs robust machinery, electronics and programming. E.g., once a large generator starts oscillating irregularly it can inject unstable or out of sync power into the grid causing local instability.
Throughout the last decades there were a few major interruptions leading to blackouts, e.g. 2003 when a high-voltage powerline shorted due to its close proximity to a tree and the Italian power grid blacked out for more than 15 hours.[5]
In a large grid system with so many different participating countries there is a range of challenges to the stability of the grid. There are different energy policies, the infrastructure quality varies as well as the levels of renewable energy integration. These differences lead to imbalances in production and demand, especially when weather-dependent sources fluctuate. This requires real-time data sharing, technical alignment, and political cooperation, which are not always consistent across borders. Countries like the Netherlands and Germany invest more and more in smart grid technologies and cross-border interconnectors but others lag behind due to financial or regulatory barriers. This creates strain and bottlenecks on the grid, for example, because surplus electricity sometimes cannot be distributed properly leading to overloads or frequency deviations.
Fail-safes
On 8th January 2021, the CESA experienced a major grid split due to equipment failures and the resulting overload in the transmission network, temporarily dividing the system into two areas. In response several automatic safety measures were triggered which prevented a widespread blackout. This is one example that showcases why a blackout like the one on the Iberian Peninsula is unlikely to happen very often. There are simply too many fail-safes in place.
The grid includes three levels of backup: fast automatic responses to sudden changes (FCR), systems that restore normal frequency over time (aFRR), and manual backups for larger problems (mFRR). If the frequency drops too much, certain parts of the grid are automatically shut off (UFLS) to stop the problem from spreading. Something similar happened last week in Portugal, Spain and France, basically creating blackout »islands«.
One fail-safe mechanism which surprised me was the sheer scale of so-called synchronous condensers. These are spinning machines that act as fail-safe mechanisms for the power grid, helping to maintain stability by supporting voltage and frequency through spinning at a precise frequency. That is becoming increasingly important in the CESA as renewable energy sources replace traditional power plants.
The biggest synchronous condenser weighs around 390 tons – around the weight of one empty Boeing 747 or two blue whales – and is located in Latvia.[6] The biggest one in the world weighs 775 tons and is located at the JET research facility in the UK.
Other systems (such as AGC) adjust how much power generators produce to keep supply and demand in balance. Special protection systems (SPS) also watch for trouble and can quickly disconnect equipment if needed. All of this is supported by a communication system (EAS) that lets grid operators across Europe act together in real time.[7–9]
Smart Grids
The CESA is not yet a smart grid but incorporates some features of it such as the increasing level of automation, real-time grid monitoring (via SCADA[10] and the EAS platform) and feature pilots. Those are essential in preventing large-scale breakdowns of the system and decrease reaction time to problematic incidents substantially.
The increasing complexity of the requirements to the European grid system such as the incorporation of renewables, paints a rather clear picture of the direction it has to take: It needs to become smarter.
Why is that? In short: A smart grid is an advanced electricity network that uses digital communication, real-time monitoring, and automated control to balance energy supply and demand efficiently across all parts of the system. Since it’s more efficient than traditional power grids, it’s also more sustainable and provides greater electricity availability. For example, it can instantly reroute power to critical areas to avoid outages or enable households with solar panels to dynamically feed surplus energy back into the grid.
The key benefits are a two-way communication vs. the one-way flow of the traditional grid system – consumers can now act as active producers or »prosumers«. Traditional grids rely mostly on manual checks, scheduled maintenance, and slower responses to faults or outages. Smart grids use digital sensors, smart meters, and automated controls to ensure constant monitoring and to make adjustments in real time.[11–14]
The big change: Including renewables and earning money
Traditional grids are built around large, centralized fossil-fuel plants. Smart grids are designed to integrate diverse, decentralized energy sources like rooftop solar, wind farms, battery storage, and electric vehicles — managing their variability and ensuring grid stability through intelligent coordination. On a smaller scale, it is already possible to make use of that as part of a smart home, smart grid system. During a very sunny day if the consumer uses solar panels to generate electricity, the excess energy can then be stored in large batteries and be distributed across the system. It can be used to charge a private electric vehicle or to be fed back into the system to earn money based on dynamic pricing, peer-to-peer trading, or grid services participation. Of course, for such a system to function a robust software environment and energy management platform is needed.
Even though I dislike Tesla as a company for several reasons they have created a few technical milestones and offer an integrated micro-grid solution:
In Germany you could already earn money by feeding excess energy back into the system, e.g., using fixed feed-in tariffs but without real-time spot market pricing or feedback. To make use of a smart grid infrastructure and earn money from excess electricity generated through renewables, quite a few prerequisites have to be met such as having a contract with a dynamic tariff provider and you’d have to own a smart meter, among many other things. Unfortunately, the general rollout of such smart meters has been tremendously slow in Germany, similar to other digitization projects. That is also due to profit-driven interests of companies which benefit from reinstalling updated versions of older systems instead of real smart meters and lax policy enforcement on a federal level. As a result, currently just over 2% of metering points are smart meters. It will probably still take more than a decade for smart metering to really have an effect on the overall market.[15, 16]
Micro smart grids
As a key factor in creating an overall flexible power grid, a decentralized approach is needed, involving the implementation of micro smart grids. Those micro smart grids are small-scale, digitally controlled energy systems that operate either independently or in coordination with the main power grid, combining local electricity generation, storage, monitoring and flexible consumption. For instance: The Fraunhofer IAO's Micro Smart Grid in Stuttgart serves as a living laboratory for decentralized energy systems. It integrates over 70 electric vehicle charging stations, photovoltaic panels, lithium-ion batteries, and a pioneering liquid organic hydrogen carrier (LOHC) system for long-term energy storage. These components are interconnected via a direct current (DC) intermediate circuit and managed by an in-house developed energy management system, enabling real-time coordination of energy production, storage, and consumption.[17-19]
Another example is Aral’s micro smart grid project. Germany's largest gas station chain opened a microgrid-powered mobility hub in Berlin, utilizing renewable energy production to charge electric vehicles.[20]
On a larger, national scale, Creos Luxembourg, the main grid operator of the country, is modernizing its electricity network through large-scale smart meter deployment, digital grid management tools like grid digital twins, and enhanced data analytics for efficient energy distribution. Additionally, it supports sustainable mobility by expanding its national EV charging infrastructure (Chargy), integrating it with smart grid systems for load balancing and energy optimization. Such a wide-scale system could also include local micro smart grids.[21]
Cybersecurity… and vulnerabilities
On the flipside, smart grids face several challenges including higher initial investment costs, the complexity of integrating decentralized and variable energy sources (like solar and wind), and regulatory and market design barriers that are still evolving to accommodate flexible, dynamic grid operations. The most prominent threat that is highlighted in the media is cyberattacks.
Power grid systems become increasingly vulnerable to them due to their high reliance on digital communication, interconnected devices and automation. These vulnerabilities can lead to disruptions in power supply and compromise sensitive data through denial-of-service (DoS) attacks, data integrity breaches, and desynchronization attacks. Such attacks can range from smaller private energy theft to large-scale terrorist attacks being executed remotely, shutting off or overloading parts of the system. And those are not theoretical. Attacks to the digital electric grid infrastructure have been happening for decades.
The IEEE highlights that smart grid security risks fall into categories such as attacks against devices, communications and systems, and emphasizes the need for robust cybersecurity measures.
To address the growing cybersecurity risks in smart grids, utilities are suggested to implement layered defenses including data encryption, strong user authentication, VPN-secured communication, and network intrusion detection and prevention systems (IDS/IPS). Additionally, they must adopt new approaches that balance security with performance, invest in technologies that both detect and respond to threats and further develop self-healing mechanisms.
Last but not least, they must maintain transparency with consumers about data usage to build trust and resilience in an evolving energy market landscape that is subject to new profit interests and cyber threats.[22, 23]
[7] Short explanation of the CESA’s major fail-safe and monitoring mechanisms:
FCR (Frequency Containment Reserve): An automatic grid response that stabilizes frequency immediately after a disturbance by adjusting power output.
aFRR (Automatic Frequency Restoration Reseve): A control reserve that automatically helps restore frequency to normal levels over several minutes after a disturbance.
mFRR (Manual Frequency Restoration Reserve): A manual backup reserve used to address sustained imbalances or disturbances in the power grid.
UFLS (Under Frequency Load Shedding): An emergency measure where parts of the grid are automatically disconnected to prevent system collapse due to low frequency.
AGC (Automatic Generation Control): A system that adjusts the output of generators in real time to balance electricity supply and demand.
EAS (ENTSO-E Awareness System): A communication and coordination tool used by grid operators across Europe to share real-time status and event information.
Let me know what you think