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Join usPP1 and PP2: grid stress days for load shedding
With the growing share of renewable energies in the French power system and the electrification of use, the need to balance the supply and demand of electricity is becoming more and more important. To help achieve this balance, RTE (France’s Transmission System Operator) is implementing measures to secure the electricity supply, particularly during periods of high grid stress (PP1 and PP2 days).
Capacity mechanism: the origin of PP1 & PP2 days
Formalized by the French government and instituted in January 2017, the capacity mechanism is a policy designed to safeguard France’s electricity supply in a sustainable way.
To avoid blackouts on the national power grid, particularly during winter periods, each electricity supplier must have a number of capacity guarantees to cover its customers’ electricity consumption, particularly on days of high grid stress. Specifically, this involves guaranteeing electricity generation capacity or guaranteeing load shedding capacity for certain consumers. These guarantees enable RTE to ensure that peak periods (or consumption peaks) can be covered by sufficient electricity production or by load shedding.
Such provisions are essential in light of the development of so-called “intermittent” renewable energies and the electrification of use. Indeed, while the development of stationary storage solutions means that energy can be stored for a few hours and fed back into the grid when it is most needed, the power generation resources available are sometimes insufficient to meet the country’s overall consumption. For that reason, the grid operator calls on other systems, such as load shedding.
PP1 and PP2, or high grid stress days
The abbreviation “PP” stands for “Peak Period”. Consequently, PP1 and PP2 are days of tension on the electricity grid, also known as “peak consumption days”. These are days when electricity consumption on the national grid is very high, generally during the winter period.
These days of high grid stress are days on which power system players, such as producers, heavy consumers or operators with storage assets, are on standby in case RTE calls on them to secure the electricity supply. Through the capacity mechanism, “RTE publishes each day in day-ahead the peak period (PP) type:
- the notification of PP1 days and PP2 days that are also PP1 days will be
published the day before at 9:30 am - the notification of PP2 days that are not PP1 days selected on a consumption
criteria will be published the day before at 9:30 am; - the notification of PP2 days that are not PP1 days selected on a system stress
criterion will be published the day before at the latest at 7 pm.
For information, between 09:30 and 19:00, a signal marked “Awaiting publication” means that the day is non-PP1.
PP1 days may only be selected from the business days of the delivery period of the delivery year, excluding Christmas school holidays of the delivery year as defined in the national school calendar order in force.
PP2 days may only be selected from the days of the delivery period of the delivery year, excluding Saturday and Sunday, and may not be selected from Christmas school holiday days of the delivery year as defined in the national school calendar order in force.“*
In addition to fulfilling a need when the power grid is under stress, PP1 and PP2 days are also a way for consumers to learn how to better manage their electricity consumption, notably through load shedding.
On PP1 and PP2 days, the aggregator or “load shedding operator” triggers load shedding on behalf of its customers and valorizes this load shedding on the wholesale electricity market, enabling them to obtain remuneration for this consumption modulation.