Did Emmanuel Macron follow the last RTE conference? This is what one might believe when listening to the televised intervention of the Head of State this Sunday, during which he declared that France would abandon coal in 2027, converting its last two plants within the framework of ecological planning. “By 2027, what are we going to do? We still have two coal-fired power plants, Cordemais (west) and Saint-Avold (east), we are going to convert them completely to biomass,” he said in this regard. the “first very concrete measure of this planning”.
Four days earlier, the electricity transmission network operator presented its updated forecast report for the period 2023-2025 within the framework of France’s carbon neutrality goal. RTE had mentioned in particular the need to use thermal power plants to guarantee security of supply between now and 2030 in case the availability of the nuclear park does not return to 2010 levels, if the sobriety strategy does not reach a sufficient level or if The development of renewable energies was too limited.
The RTE representative then added that a small amount of biomass would be necessary “to the extent that these coal-fired power plants would operate very little”, which would correspond to the downward revision of the biomass potential available to decarbonize the economy confirmed . a recent presentation by the general secretariat of ecological management last July. So how will this conversion from coal to biomass power plants take place over the next four years?
Electricity and heat, an example of “cogeneration”
More than eight years ago, EDF published a video describing the operation of a biomass power plant. In short, this type of infrastructure produces electricity from the heat released by the combustion of organic materials such as plant waste, household waste, biogas from the fermentation of waste, that is, renewable energy sources available in large quantities. Subsequently, the fuel is transported to the boiler and introduced into the fuel chamber where it releases heat as it burns. This heat is transmitted to the water-filled tubes that line the boiler. The water in the tubes thus heated is directed towards a balloon where it is transformed into steam.
This steam spins a turbine and this, in turn, spins an alternator. In the latter, the interaction between the electromagnets of the rotor, the moving part, and the copper wire coils of the stator, the fixed part, produces an electric current. A transformer raises the voltage of this current to 225,000 or 400,000 V so that it can be transported more easily on the very high voltage lines of the network.
For its part, the steam that leaves the turbine passes to a condenser through which cold water circulates. It is transformed back into water to be returned to the boiler. This steam can also be reused either for industrial activities or to supply an urban heat network. This simultaneous production of electricity and heat in the same facility is called “cogeneration”. Finally, the fumes resulting from combustion are filtered before being evacuated through the chimneys.
The Ecocombust 2 project at the Cordemais power plant
Coincidence or not, it turns out that an important project to convert power plants from coal to biomass enters a decisive phase starting this Monday. Indeed, the inhabitants of the municipality of Cordemais can participate from today until October 27 in the public investigation on the project called “Ecocombust 2”. The latter foresees the creation of a pellet factory on the site of the power plant: specifically, residents will be able to give their opinion on the application for environmental authorization. The investigative commission can then give the green light to the publication of an authorization order issued by the prefect of the department… or decide to reject it. The established calendar aims to begin construction works in the first half of 2024 for its start-up starting in 2026.
The reconversion project initiated in 2015 by the plant’s employees should guarantee the continuity of the activity and safeguard the approximately 600 direct jobs on site. It should also allow the power station that supplies a quarter of the Loire Country’s electricity needs to reach carbon neutrality thanks to the 160,000 tonnes of pellets produced per year. Il avait déjà enregistré une victoire important en janvier dernier lorsque le ministère de la Transition écologique avait donné son feu vert, dans le cadre d’un appeal à manifestation d’intérêt (AMI), quelques jours après le début d’un mouvement de grève employees.
A cost of about 200 million euros
Ecocombust experienced twists and turns before stabilizing in recent months. In its initial form, the project was carried out jointly by EDF and Suez, but was abandoned by the government in July 2021, in particular due to the withdrawal of Suez and a cost considered too high. In 2015, EDF invested 10 million euros for the first time in this reconversion project as a result of the energy transition law for green growth. When it was relaunched within the framework of the AMI “for the development of thermally treated biomass pellet plants, mainly from wood waste”, the second version of the project could count on the arrival of Paprec as the only pilot, while EDF was It limited itself to providing the land and patents for the Ecocombust process.
Although the location of the plant was changed, the recycling company also greened the project by choosing to fuel the boiler that will produce steam with recovered solid fuels (CSR). Ultimately, the total investment would amount to 220 million euros, between contributions from the Paprec and EDF groups and French and European public aid that contributes to a third of the bill through the Just Transition Fund.
Previous projects criticized
Ecocombust is not the first project to convert thermal plants to biomass. On the other side of the English Channel, precedents have been criticized on several points. Critics of biomass power plants criticize them in particular for the significant emissions of fine particles, the heavy investments to avoid the phenomenon of corrosion and two power plants that had to close a few years ago after fires. Above all, the supply problem stands out, since to supply pellets, certain infrastructures resort to imports from other European countries, or even from North America, which degrades their carbon footprint.
French facilities have faced this problem. This is the case of the unit operated by the German company Uniper in Gardanne, in Bouches-du-Rhône, which ended up losing its exploitation right in 2017, due to lack of sufficient local resources and due to competition with other activities to benefit from it.
In Réunion, the ongoing conversion of thermal power plants does not allow for complete decarbonisation, as pellets are imported, among other countries, from the United States and Canada, pending the development of a sustainable sector in South Africa. As for Ecocombust 2, Paprec plans to transport furniture or construction wood waste by boat from Brittany and Loire-Atlantique.
Source: BFM TV
