Description and Planning of Operation

The operation of the electricity transmission system must ensure the safe and uninterrupted supply of the Hellenic Electricity Transmission System (HETS), 24 hours, 7 days a week, 365 days a year. According to the laws of physics, electricity production and consumption must be balanced at all times on the electricity systems.

Employees in the Operation Department are responsible precisely for this balance, by increasing production when more power is needed or by decreasing it when there is more power available than what can be absorbed or transferred.

Balancing is highly challenging work, with the constantly growing penetration of Renewable Energy Sources in the HETS which have a volatile and stochastic nature, therefore their injection may change over very short time periods, depending on the time of day and weather conditions.

The system's operation is designed and scheduled, taking into consideration all those factors that affect it (weather conditions, particular constraints, availability of elements, etc.) and are then supervised in real time by the Energy Control Centers.

The transmission of electricity from producers to consumers requires a harmonious collaboration between power networks of different voltage levels. In the Greek electricity grid, the experts are responsible for inspecting the system and ensuring the country's safe and uninterrupted supply with power.

To fulfil this mission, network control and management tools are used, as well as market mechanisms that have a regulatory effect on the System. The operation and control of the System is carried out in accordance to solutions exported by the electricity market and are based on technical and financial offers, which are then implemented in real time, mainly by the National Energy Control Center, as well as the three Regional Energy Control Centers.

Operational Planning procedures aim at the safe operation of the Hellenic Electricity Transmission System (HETS).

The main processes relate to the design of the isolations of the interconnections and main elements of the HETS, as well as the Power Plants, to ensure the country’s uninterrupted supply with electricity and the reliable operation of HETS.

In parallel, analysis of capacity adequacy and reserve of the control area, and the creation of the Individual Grid Model showing the existing topology of the network, with the forecasts for production, load and flow to the interconnections, are basic pillars for the Operational Security Analysis of the HETS.