Next winter is likely to be tense on the French electricity grid if the majority of nuclear power plants remain shut down. There is still uncertainty despite the recent reboot announcements.

The electrical system manager then has several means at his disposal in order to manage his various voltages. The load shedding is one, which is used only if the other means at its disposal are no longer available or already exhausted.

It is quite rare to see this device be triggered, however the recent tensions on the markets and the unavailability of power plants are bringing this subject back to the forefront.

What is load shedding? What are the impacts of electrical load shedding on businesses? And what are the different load shedding scenarios in France for 2023? Answer in this article.

What is load shedding?

The principle of load shedding in an electrical network is quite simple. It's about the voluntary cessation of electricity supply of one or more consumers to restore the balance between production and consumption on the network and thus maintain the frequency around 50 hertz.

It is one of the last ways available network operators in order to avoid cascading drops in voltage and frequency.

To avoid a collapse of the electrical system, we stop supplying certain areas.

As we explained to you in our previous article on the Electric blackout, a balance problem between electricity production and consumption can trigger a cascade reaction. To avoid this, load shedding is a last resort.

It is also possible to equip yourself with loaders in order to cut off the power supply to certain installations within companies and even in individuals.

Why do an electrical load shedding?

Electrical load shedding: when?

Electricity is an energy that does not Can not be stored on a large scale. However, it has the physical characteristic of having to maintain a perfect balance between supply and demand.

When consumption exceeds production, the balance of the entire electrical system is at risk. It is one of the main missions of network managers to ensure that this balance is maintained.

To do this, they have several means of intervention. For example, there are several power reserves ready to support the frequency of the grid if a nuclear power plant were to suddenly disconnect.

One of these methods is electrical load shedding. It mainly intervenes in two cases:

• One manual load shedding, planned when there is a shortage of electricity in a specific location (if a power plant were to shut down or an interconnection line was damaged);
• One automatic load shedding if it happens suddenly following a natural disaster or storm.

The different forms of electrical load shedding

There are 4 different forms of electrical load shedding:

• Load shedding on order, triggered by the network manager;
• Load shedding on energy metering ;
• Load shedding on power or frequency thresholds, it is a measure triggered when a group of sites exceeds the power threshold or the limit frequency threshold in the zone;
• Contractual load shedding (via specific interruptibility devices), when available.

These measures are not all triggered at the same time, depending on the situation, but this measure remains exceptional.

In France, the operational results of network operators Enedis and RTE are still very robust, the average outage time is one of the lowest in Europe.

Load shedding has sometimes been used sparingly, but the tensions coming next winter suggest that its use will be necessary. All this will depend on the level of availability of EDF nuclear power plants.

The energy markets remain very tight with, for the main reason, The conflict in Ukraine. This exceptional situation may require the use of measures such as load shedding.

What are the impacts of electrical load shedding on businesses?

If the network situation is so critical that it is necessary to trigger automatic load shedding measures, the companies concerned will suffer a stopping the electricity supply to their sites. This can be very harmful, but this measure is in response to an emergency situation.

The Power Transmission Network Defense Plan provides for 5 measures, and automatic load shedding is the last. Before that, some companies that have signed an interruptibility contract may be called in order to cut off their power. These shutdowns are paid according to the terms of the contract and therefore anticipated by the companies concerned, in contrast to load shedding.

Who is affected by electrical load shedding?

Electrical load shedding can concern a wide range of customers, both professionals and individuals. As far as businesses are concerned, they are generally companies in the agricultural or industrial world located in rural areas.

Their load shedding is simpler from an operational point of view and involves only a few power lines. It is thus easier to manage for Enedis or RTE.

Many businesses are already used to modulating their electricity consumption with erasure contracts or other measures. However, these measures may also be subject to companies located on a zone of tension.

Some installations are protected against this type of voluntary power cuts. It is mainly about emergency services as well as hospitals. Some administrative buildings or servicemen sensitive people are also concerned. It is also possible to have a rescue group in order to avoid this type of damage.

The different load shedding scenarios in France for 2023

Several scenarios are to be considered in the event of major tensions on the network for the winter of 2023.

The most likely scenario is that of a punctual load shedding And in a way rotating. That is to say, the electricity supply to certain areas (a neighborhood, a small town) is cut off during two hours maximum before changing the zone. This makes it possible not to penalize the same customers for a long time.

It is also possible for the network operator to Lower the voltage from 230 to 220 V. This will have the effect of reducing the power delivered to the network, making our electrical devices a little less efficient, and our bulbs less flickering. Add to this that these cuts, if they occur, are planned over very specific periods: between 8 am and 1 pm or 5:30pm and 8:30pm.

If the situation is extreme, it is possible to see Larger cuts (geographical or over time), but this scenario remains very unlikely in France.

The availability of nuclear power plants is the unknown in the current electrical system equation and for next winter. If the situation recovers faster than expected, the tension on the network will be greatly minimized.

The situation in Ukraine may also have consequences for tensions in Europe in terms ofgas supply. These two parameters will be key in determining the state of the electrical network in France and Europe in the coming months.

For more information, do not hesitate to consult our article Why does the price of electricity depend on gas?