Greek PPC: Modern capacitors breathe new life in old lignite units

PPC plans to turn the former lignite station of Kardia in Western Macedonia into a “pillar” of stability of the electrical system, providing energy storage services as well. In fact, a few days ago, the new Environmental Conditions Approval Decision was signed by the competent Environmental Licensing Division (DIPA) of the Ministry of Environment and Energy, which paves the way for the conversion of the generators of the “Kardia III” units. and “Kardia IV” inτο modern capacitors in order to offer services to the electricity transmission network (power and voltage regulation, electricity storage).

The Investment

As reported to ΟΤ by a PPC executive, the company has already been planning this investment since 2019, looking on the one hand for ways to utilize its lignite units which are gradually being “locked” in the context of delignitization, and on the other hand, technologies to support the stability of the electrical system, as long as the penetration of Renewable Energy Sources (RES) is increasing and large energy storage units have not been installed.

In fact, the relevant tender for the study, supply, installation and operation of the project has also started, which will be put into operation 15 months after the signing of the contract with the contractor. The Kardia Thermal Power Station, which is no longer operational, is planned to be transformed into an innovative hub, which will “host” modern energy technologies and services.

Capacitors

The modern capacitors that will be installed there will be the first in Greece and will provide critical services for the stability of the system. In fact, as stated by the PPC executive, it is possible that the project will be a “pilot” for the utilization of the company’s remaining lignite units, which will gradually be closed as part of the government’s delignitization plan.

“It is a form of energy storage. We need such services to support the country’s electrical system from the problems of overvoltage that have started to appear from the high penetration of RES. It is a very important investment that serves the vision of delignitization and the green transition,” he notes. And he adds: “At the same time, the existing infrastructures are also being used, which will be maintained, while the company’s staff will also be employed there. The conversion of the generators of the two units into modern capacitors is one of the most modern and economical solutions that guarantee stability in the system. This opens up a new market which will strengthen the security of the system, but can also lead to a reduction in energy costs”.

Internationally, the large synchronous generators of conventional power plants, which are decommissioned and replaced by RES units, remain useful as they are converted to synchronous capacitors, continuing to provide support to the power system and upgrade the quality of the power grid.

Kardia steam generator unit

As for the Kardia units, its four lignite units initially entered a regime of limited operation of 17,500 hours (Units I and II) and 32,000 hours (Units III and IV), while later they were put into permanent shutdown, with the last Unit IV on May 5 2021. Now, the generators of Units III and IV which will be converted to synchronous capacitors, will operate consuming electricity from the grid, four emergency generators and an auxiliary steam boiler in operation consuming diesel oil.

The facilities of the boilers and the district heat pump station are also located within the area of the Kardias NPP, and in the future, High Efficiency Combined Heat and Power (CHP) units, natural gas boilers and a new district heating pump station will be installed. All these units are already environmentally licensed or are in the planning stage and will be licensed in the future.