The system separation in the Continental Europe synchronous area highlighted how interconnected electricity systems are and how important is the role of Transmission System Operators (TSOs) in securing energy supplies.
Innovation, digitalisation, flexibility and interconnections are just some of the solutions to adapt to this fast-changing environment.
CEENERGYNEWS spoke with András Biczók, CEO of the Hungarian Transmission System Operator MAVIR about the different tasks and responsibilities of the TSOs, the role of renewables in the electricity sector and what to expect from 2021.
The initial event of the system separation that occurred on 8 February was the tripping of a 400 kilovolt (kV) busbar coupler in the substation of Ernestinovo, in Croatia. The separation of flows in Croatia led to the shifting of electric power flows to neighbouring lines which were subsequently overloaded.
“The systems themselves reacted as they were supposed to: the response was fast and the coordinated actions taken by TSOs in Continental Europe were adequate,” Mr Biczók begins. “We can say it was a successful exam with all system operators in contact within 30 seconds. The automatic activation of power stations throughout Europe and the automatic initiation of contracted load shedding in Italy (1000 MW) and France (1300 MW) kept the grid stable and the European electricity grid returned to normal conditions in around one hour.”
Of course, he highlights that nobody can train live for these kinds of situations and we can only be prepared. Although TSOs operate through advanced IT systems, at the end of the day it is about manpower and people’s skills.
“It is the task and responsibility of the TSOs to be prepared for a power supply under rapidly changing industry circumstances, like the change in power production structure being in progress or the shortened lead times,” he explains. “When analysing these situations we have to take into account three aspects/preliminary conclusions that are not dependent on the outcome of the official investigation: first, the interconnectivity between countries and regions must be more robust than it is now. Secondly, we need to have reliable domestic power supplies and finally, cooperation is key.”
“Symbolically saying, it is one interconnected power transmission network stretching from Portugal down to Turkey.”

Flexibility is an increasingly important aspect of the security of supply, supported by market instruments, not only the coupling of markets, but also the reduction of lead times, the development of new role models like aggregators and energy communities, the development of new common European energy balancing platforms using standard and non-standard products, more strict scheduling procedures, the introduction of new capacity calculation methods, the establishment of new frameworks for a new TSO-DSO cooperation model, but also giving the change for all renewable power generators joining the flexibility market.
“However, it is also a precondition to account for a continuous expansion and the strengthening of the national and international transmission line connections is extremely important,” Mr Biczók says. “In line with all these developments, we were – together with the Hungarian Energy and Public Utility Regulatory Authority (MEKH) and DSOs – developing a new method of the Network Development Plan, that lays down a TSO-DSO harmonised grid development procedure, taking into account – besides classic physical asset development – also innovative solutions.”
“This will enable all system operators not only to react but also to act to handle changes occurring due to a large number of renewables appearing as network connections.”
Besides investing in the assets of the grid, for MAVIR it is also of utmost importance to have a common energy industry based outlook on the ways and solutions to involve renewables fully in the power market, including their participation in the balancing mechanism.
Renewables represent an increasing share in Hungary’s generation mix, a tendency which is also underlined by the ambitious targets of the new National Energy Strategy and National Energy and Climate Plan. Mr Biczók points out that in 2020 nuclear accounted for 47.98 per cent of the country’s energy mix, renewables represented 13.21 per cent and gas 27.01 per cent.
Here, a much more closer TSO-DSO cooperation is needed, not just because of the flexibility but also because of network planning or enabling interconnection for the new renewables coming up. As the CEO of MAVIR highlights, there is a special need for the full integration of renewables in the ancillary services. And this is something the entire region should work on.
“The region is going after a general trend which is increasing renewable energy sources,” he says. “However, each country has a different background. Hungary for example is designed more for solar power, while Slovakia counts more on hydro sources and Poland is exploiting offshore wind.”
“It is also a common goal to emphasise the importance of maintaining the capacities of large scale power generation assets, either via upgrading existing power plants to boost its speed, flexibility or via newly built entities to enter the market,” Mr Biczók continues. “Especially the flexibility market will need special attention in the next decades.”
In this regard, the 750 billion euros post-pandemic recovery fund, called Next Generation EU, could really make a difference.
“We don’t know yet the exact figures but we are very positive that it will be a significant amount especially for the electricity grid as an investment to upgrade the grid is key in order to have higher capacity on certain transmission lines and substations,” reveals Mr Biczók.
Speaking of the security of supply, market interconnections are very important. Last October works to build the 80-kilometres-long 400 kV transmission line Cirkovce-Pince connecting the Slovenian and Hungarian transmission networks have finally started. For Mr Biczók, strengthening the national network is needed to enable renewables to physical connection but also to handle the new flows originating from the change of the power production structure.
“As it concerns the international grid developments, we are now finalising the missing interconnection with Slovenia, the only neighbour without direct access so far,” he underlines. “The Hungarian section of the interconnector was completed years earlier by MAVIR. The establishment of the missing 80-kilometres-long 400 kV Cirkovce-Pince section planned for 2021-22 on the Slovenian side by our Slovenian counterpart ELES will be a significant step for both MAVIR and the Hungarian energy market as the flow will be easier and the energy supply will be secured. It will also be a huge highlight that this spring we will finalise the Slovakian-Hungarian interconnectors, that supports ultimately the main import and transit north-south route and enables via this also the enhancement of the energy security of Eastern Hungary.”

Mr Biczók recognises a fundamentally changing environment in the electricity sector with changes in the regulation (for example, clean energy package, green deal), accelerating development and requirement due to IT/digitalisation, new technologies entering this market (e-mobility, storage, smart technologies), new energy trends (renewables, real-time or close to real-time operational procedures), new roles, new partners appearing (aggregators, new TSO-DSO cooperation models, prosumers, regionally covered energy security instruments), new financing issues to be covered, the need to have properly educated, trained, qualified and prepared human resources in place and, last but not least, the overall social and business environment, including situations like the pandemic one and the resulting economic consequences.
“Having all these aspects simultaneously, MAVIR has a duty to provide for the basics, enabling the security of supply, meeting the climate goals and to account – as long as it is in the scope of a TSO – for the affordable energy prices,” the CEO of MAVIR notes. “All this needs to be met at the same time, by providing for a stable and robust operation while flexible, open and capable for integrating all the changes.”

“That’s why the company is currently dealing with a number of things,” he emphasises. “In 2021 we are looking forward to the new Slovakian-Hungarian interconnectors Sajóivánka-Rimaszombat 400 kV and Gönyű-Gabcikovo (Velky-Dur) to start operating in the second quarter. In both Hungary and Slovakia, the tie-lines increase the security of electricity supply in the affected regions, thus ensuring the operational security of the European electricity system and greatly contributing to the integration of electricity markets.
“There are also multiple projects we are implementing simultaneously at the moment with very strong IT focus and certainly this is a challenge,” Mr Biczók says. “Especially the security of supply and securing the balance each and every second is extremely important having in mind the new challenges and the new RES producers being in pace.”
“I would like to emphasise the importance of traditional [power] producers whose contribution are still essential for balancing,” he concludes. “From a market operation point of view more efficient cross-zonal capacity allocation, improving price convergence both on the European and regional level and more efficient management of market participants’ physical positions (continuous trading, quarter-hourly product) supporting RES integration are key tasks for all TSOs and so is for MAVIR.”