Are we threatened by scheduled power outage without the coal-fired plants?

Traditionally, in the beginning of the winter season a review is made of the power capacities in the country and the risks to the power supply. Just a few days ago it became clear that a report, elaborated by ENTSO-E, the European Network of Transmission System Operators for Electricity, puts our state among the countries threatened by scheduled power outage. Bulgaria, together with Cyprus, Malta, Corsica, and Crete face a real risk to experience significant power shortage by 2020. And while this seems normal for island territories, where connectivity to the grid is difficult, for Bulgaria these conclusions are worrisome, given that the state has been among the energy market leaders in the Balkans for many years. According to the ENTSO-E forecast, Bulgaria is facing the risk to be unable to meet its electricity consumption for several hours and the power system – not be able to compensate this either with domestic production, or through import.

Similar unfavorable forecast is made also in the report, prepared by the Electricity System Operator (ESO). The operator published a draft Plan for development of the electricity transmission grid in Bulgaria for the period 2018-2027. The plan includes analysis of the electricity consumption, the generation capacities, as well as projections about capacities and the energy system balance, etc. It is clearly stated that the existing reserve capacities would not be sufficient to secure the consumption and the planned trade export if there is extreme consumption combined with breakdowns of generation capacities. In other words, Bulgaria is endangered by scheduled power outage if in a harsh winter some of the capacities fail to operate.


Reliability Proven in Tough Times

And this is not only a hypothetical scenario. Evidence for such an occasion is the situation that the state faced just a year ago. Then, in the winter of 2017, the long low-temperature period resulted in a record power consumption increase. This on its turn led to capacity breakdowns, to exhausted primary energy source and to inability of some power plants to start operating. So Bulgaria was on the verge of having scheduled power outage and suspended the electricity export. In a situation like this it is easy to see the key role of technologically advanced power plants. Practically, the only power plant built in Bulgaria since 1989, has been TPP AES Galabovo. In the cold January of 2017, the most modern power plant in the state produced nearly 466 000 MWh of electricity, which was about 10-11% of the generation in the country. The average hourly load of the power system in January 2017 was 6047 MW, of which 626 MW was provided by TPP AES Galabovo’s operation. In such harsh weather conditions, if Bulgaria does not have capacities like TPP AES Galabovo, it might be forced to seek options to change the 24-hour load profile of industrial consumers and even to consumption restrictions in certain peak hours.

Thanks to the 690-MW capacity in Maritsa East basin, Bulgaria meets ENTSO-E’s requirements for primary regulation reserve. The technical parameters of TPP AES Galabovo makes it the most efficient plant for the purposes of ESO balancing the state’s power system. The main advantages of the power plant are a fast balancing service of ±6 MW/ minute step of ramp up and ramp down of the unit load and the larger capacity of the secondary control units, 180 – 343 MW gross block range per unit. The power plant is able to achieve load of ±15 MW per unit for 30 seconds in the primary control, maintaining this load for 30 minutes in primary regulation.

The 690-megawatt TPP AES Galabovo provides about 10% of the energy in Bulgaria.

For reference, the other plants participating in the system’s primary regulation maintain a range of ±10 MW. Furthermore, without TPP AES Galabovo, the state will experience problems with the sub-peak mode. ESO’s Plan clearly indicates that at very low temperatures with no wind, meaning no wind power generation, the balance between generation and consumption is hard to keep. This leads to difficulties in supporting the voltage in North-eastern Bulgaria, due to the concentration of wind farms in the region. This is why TPP AES Galabovo is of strategic importance to Bulgaria to support voltage levels and balance of reactive capacities in the electricity transmission grid. Thanks to its flexibility the coal-fired plant proves to be of key importance for the state’s energy system dispatching.


State-of-The-Art Technology

The American corporation AES invested in TPP AES Galabovo more than BGN 2.6 billion, making it the largest foreign investment in Bulgaria’s energy sector. The plant is designed to work in compliance with the emission standards for dust, nitrogen oxides, sulphur dioxide and reaches desulphurization of about 98%. Flue gases are let out in the atmosphere only after passing through the flue gas desulphurization installation, and the power plant could not operate if the FGD installation stopped. This guarantees that the air is protected from pollution with sulphur dioxide. Various systems and equipment are constructed at TPP AES Galabovo, securing closed-loop water cycle. Wastewater is filtrated and reused, which reduces the total amount of water for production needs. The power plant has zero wastewater discharge and applies a modern filtration technology, allowing effective and secure operation with minimum use of chemicals.


Meeting New Environment Criteria

Due to all these technical and environmental advantages, TPP AES Galabovo, along with the state-owned TPP Maritsa East 2 and the other US TPP ContourGlobal Maritsa East 3, is expected to receive derogation from the stricter emission levels, set by Brussels. Several days ago Minister Temenuzhka Petkova announced that TPP Maritsa East 2 had already been granted derogation. It is expected that the Executive Environment Agency would shortly pronounce about the derogation request, filed by the two other companies and that they would continue operating even after 2021. This is when the new stricter environment criteria for large combustion plants come into force. Prolonging the operation of the power plants in the Maritsa East basin will guarantee Bulgaria’s energy and social security.


Source: Trud Daily, December 6th, 2018