Our region was hit by storms that severely damaged the electricity transmission network in several countries this August. In Croatia, this caused more high impact blackouts. Consumption fell drastically, but the amount of energy produced remained unchanged, creating a surplus on the grid and putting the TSO in a difficult situation. What can operators do in this situation and how can energy producers benefit from it? Kornél Tóth, energy market expert, says virtual power plants could be the answer.
Stanislav Chvála, CEO of Nano Energies
The electricity network is highly exposed to increasingly frequent extreme weather conditions, and it is easy to damage transmission lines, for example in a major storm. In Croatia, there have been several incidents recently, with 27 transmission line poles damaged or toppled, and the network has been severely damaged. In such cases, the blackouts cause sudden power cuts, but the energy already generated is retained. This summer we have seen similar storms in Hungary, and with the growth of renewable energy sources, it is becoming increasingly easy for the grid to become unbalanced, so it is worth being prepared for events like the ones in Croatia.
Weather disruptions mainly affect the distribution infrastructure of the electricity grid, i.e. the transmission between generation and consumption. The system continues to produce energy, also because of the increasing share of renewables, but damaged transmission lines mean that there is no way to get this energy to consumers. When some of the users are suddenly disconnected from the grid, the resulting excess energy poses a significant risk. End-user devices are not fit to handle the surplus, which can damage them and lead to dangerous accidents. In the energy system, a balance between production and consumption must be maintained at all times and producers should be regulated accordingly.
A flexibility aggregator providers help to balance the grid by coordinating consumption and production, explains Kornél Tóth, Head of Nano Energies Hungary. „During the Croatian storm, we had to hold back our partners' production for 75 minutes to stabilise the system, which ultimately freed the grid from 14 MW of excess energy. However, despite the curtailment, our customers received an extra revenue of around €10,000 instead of a loss, while the load on the grid was reduced. This type of grid balancing ancillary service is also available in Hungary, so Hungarian producers or consumers can help balance the grid in similar cases, which also means a higher extra revenue stream for them than in Croatia" adds Kornél Tóth .
Flexibility aggregators, which act as a virtual power plant and access otherwise untapped energy resources, will play a key role in grid developments in the coming years. They help suppliers produce electricity when they get the best price and consumers to use electricity when it is cheapest.
"Producers are already compensated for being on standby to reduce or shut down plant output and receive additional revenue for the activation itself. The resulting revenue covers, and usually exceeds, the amount the plant would have earned by generating electricity," adds Kornél Tóth.