In a time of climate emergency, this is a difficult choice. As France hit high temperatures, several electricity production sites with low greenhouse gas emissions were tied up last week despite an explosion in demand, while carbon-intensive power plants were called in nearly 100x to answer. Enough to increase the ecological footprint of France’s electron production to more than 110 grams of carbon dioxide per kilowatt-hour (KWh) on July 20, even though the country rarely records levels beyond 100 grams of CO2-eq/kWh.
Indeed, on that day, the power grid was powered by fuel oil combustion turbines, at a rate of 1.3 gigawatts, according to data from the national electric transmission network operator, RTE. This is the power of reactor No. 2 of the Golfech nuclear power plant, the capacity of which was simultaneously reduced to 0.3 GW due to regulatory restrictions on the discharge of hot water in Garonne (whose temperature exceeded 28 ° C).
” The means of production, especially nuclear, were at a lower level than usual. To ensure the supply of all French electricityso it was necessary to ask new means. But RTE does not discriminate on the origin of the electron, it is the market and suppliers from andYou have this arbitration ‘,” we explain at RTE, which is responsible for balancing supply and demand in the region at all times.
However, in the face of heat waves, the Nuclear Safety Authority (ASN) and the Department of Energy Transition a few days ago authorized an environmental exemption for nuclear power plants in San Alban, Golfeche, Blayet and Bougie. Objective: for these sites to temporarily exceed regulatory levels for temperature of water discharged into streams and rivers, if required by the RTE. So how, then, that the network administrator did not order the EDF to increase its production there in order to avoid the use of fuel oil?
The balance of supply and demand is insufficient
In fact, this ecological exception system turns out to be very restrictive, and cannot be activated if there is a “slight” discrepancy between production and consumption. ” when we were Request The exception is only for the issue of technical security of the network, and in no way guarantees a balance between supply and demand. In other words, we are not inviting the reactor to produce more by not respecting the usual thresholds just because we lack electricity. ‘, we define it in RTE.
Thus, the device is provided only in the event of an imminent danger on the network, the intensity of which must be constantly monitored. ” It’s like a guitar chord that needs to be pulled on both sides. If the plant is suddenly stopped for environmental reasons, the rope slows down, and the tension drops, which can damage the infrastructure. ‘, explains an expert in the sector.
This is also what happened the next day: On July 21, RTE asked EDF to guarantee the capacity of the Golfech 2 reactor up to 300 MW. This will be in the end Increased to 1300 megawatts Can we read the information note posted by the power company (Golfech 1 is closed due to lack of corrosion). However, the RTE order is not intended Balancing supply and demand for electricity ’,” explains a note from the EDF. But it will actually be used to keep the terminal at a level of activity that ensures the safe operation of the network.
called overheating thresholds in question
Such a system calls into question the trade-off between, on the one hand, the level of carbon dioxide emissions (which are very real, measurable and whose impact on the climate no longer has to be proven) and, on the other hand, the extent of a precautionary principle regarding the heating of waterways by nuclear power plants. Especially since the established thresholds are still controversial:
” Originally, it came from the scientific literature in the 1970s, with the famous Verneaux Classification setting goals and quality standards for running water. But it will likely be necessary to improve the regulations according to the feedback and data collected, with a more accurate analysis of river-by-river, environment-by-environment. […] This heat wave should prompt us to rethink applicable river temperature thresholds ‘, until last week exhibition Chief Inspector of the Nuclear Safety Authority (ASN), Christoph Quentin.
However, the announcement of the non-observance led to intense controversy: “ The discharge of very hot water into the river will lead to a loss of biodiversity resulting in an increase in the infernal avalanche cycle ‘, was even reacted on Twitter by EELV MP Sandrine Russo. But if we believe the nuclear cop, there is currently no data that demonstrates a real impact on surrounding ecosystems, whether by studying fish, plankton or cyanobacteria.