Gas
Development of new gas-fired power plants
The development of new gas-fired power plants is part of the need to ensure the reliability of the electricity system. In Belgium, the energy transition is accompanied by a strong increase in renewable electricity generation, whose output is inherently intermittent.
In this context, gas-fired power plants play a complementary role. Thanks to their flexibility, they can quickly adjust their output to balance the grid when renewable electricity generation is insufficient to meet electricity demand.
They also complement other flexibility solutions such as batteries and pumped-storage facilities. While these technologies are highly effective in the short term, their capacity remains limited. Gas-fired power plants, on the other hand, can meet longer-duration needs and help ensure continuity of electricity supply.
Through the Capacity Remuneration Mechanism (CRM), Belgium is seeking investors to install replacement generation capacity in the short term through what are known as CRM auctions. By participating in the first CRM auction, ENGIE contributed to the development of new generation capacity, which has now materialised through the commissioning of the Flémalle power plant.
The new-generation Flémalle power plant
With a capacity of 875 MW, the Flémalle power plant can produce the equivalent of the annual electricity consumption of more than one million households. Thanks to its high efficiency (63%), Flémalle emits 20% less CO₂ than power plants from the previous generation. It also offers a high degree of flexibility to compensate for fluctuations in renewable electricity generation, particularly during periods with little sunshine and low wind.
Thanks to advanced flue gas treatment technologies, the plant’s nitrogen oxide (NOx) emissions are up to 86% lower than those of certain existing combined-cycle power plants.
The plant was designed to integrate other types of fuels in the future, such as hydrogen, biogas or synthetic methane. It is also compatible with developments in areas such as hydrogen and carbon capture, utilisation and storage (CCUS).
ENGIE therefore continues to invest in different technologies that contribute to the operation of the Belgian electricity system.
Our existing gas power plants
ENGIE has been investing in natural gas-fired CCGT power plants since the mid-1990s. The six CCGT units in our current generation fleet have a total installed capacity of 3,065 MW.
These plants combine a gas turbine with a conventional thermal power plant to produce electricity. They achieve an efficiency of more than 53%. We work closely with manufacturers to make them more flexible and enable them to act as back-up units when renewable electricity generation is insufficient.
How does a CCGT work?
• To generate electricity in a CCGT plant, natural gas is first burned in a gas turbine’s combustion chamber.
• The hot combustion gases move the turbine, which is coupled to a generator that generates electricity.
• The combustion gases leave the gas turbine and move to the recovery boiler. They heat the piping in which water flows; this water is then turned into steam.
• The combustion gases then leak out via a chimney. The hot steam powers a steam turbine connected to a generator. Electricity is generated for the second time.
• Upon exiting the turbine, the steam condenses within either an air condenser or water condenser.
If an air condenser is used, the steam moves through a number of pipes and is cooled by an ambient air current produced by the large ventilators. Upon coming into contact with the cold air, the steam condenses and turns back into water flowing towards the recovery boiler. If a water condenser is used for the condensation of the steam, the reheated water is cooled in a cooling tower.
Did you know: there are no pylons or high-voltage lines around the Saint-Ghislain or Herdersbrug CCGT plants – they are all underground.
Cogeneration
Cogeneration involves generating heat and electricity simultaneously in one facility. The creation of heat is the main goal, with the generation of electricity being a secondary concern.
Our generation facilities comprise 6 cogeneration units with a total capacity of 451 MW. These facilities, which transform 85% of energy from fuel to electricity and heat, are located at the sites of our customers who need a lot of industrial heat (chemical companies at the Port of Antwerp, for instance).
We continue to enhance these partnerships and utilise our experience to benefit our business customers. All cogeneration units are tailor-made according to the customer’s needs.
Blast furnace gas
In addition to natural gas, ENGIE uses other gaseous fuels in its generation facilities. The conventional power plant in Knippegroen (300 MW) not only burns ArcelorMittal blast furnace gases, but also recovers converter gas from the steel plant. This project demonstrates our desire to team up with our customers and come up with tailor-made solutions.
The nearby Rodenhuize power plant, which produced 185 MW of renewable electricity from biomass until March 2023, serves as a "cold" or stationary reserve for the Knippegroen power plant.