All about Grid Balancing

In the energy sector, the term “curtailment” refers to the reduction of power production (“generation curtailment”) or – less frequently - power consumption (“load curtailment”) when there is too much electricity in the grid (generation curtailment) or when there is not enough power in the grid (load curtailment). Curtailment aims at lessening the stress on the grid at a given moment of the day. Most commonly, curtailment is associated with the reduction of infeed from renewable energy sources.

Ancillary services ensure a proper operation of the power grid. The grid operators (transmission grid operators and distribution grid operators) are responsible for ancillary services. To ensure a reliable power supply, it is necessary that frequency, voltage, and power load remain within certain limits. This does not happen automatically, but through continuous corrections: namely, ancillary services. The most renowned service is probably the frequency control/balancing energy. Even in the event of a blackout, ancillary services help restart the power grid as quickly as possible. Ancillary services can be divided into four sections : Frequency measure, voltage measure, supply reconstruction, and operational management.

Thu., August 13 2020, 3 p.m. (UTC+2)

Balancing Services are reactive short-term means to level out frequency deviations in the power grid. Balancing Services (sometimes also called control reserve) is one out of many ancillary services that system operators have to provide a secure power supply.

Thu., December 3 2020, 10 a.m. (CET)

The uptake of electric vehicles (EV) is accelerating across the globe and paving the way for clean mobility. EVs can play a key role in the energy transition with their massive storage potential and charging capacity. Orchestrated in a Virtual Power Plant, EVs provide a clean and distributed alternative to conventional power plants in keeping the grid in balance.

The automatic Frequency Restoration Reserve (aFRR), also known as secondary reserve, is a reserve in the power grid that helps to keep the grid frequency stable. To keep the frequency within certain thresholds, the Transmission System Operators (TSOs) activate balancing services like aFRR, which they acquire from Balancing Service Providers (BSPs). Countries differ in their specifications but after European harmonization of the balancing markets, BSPs need to ensure that they provide the reserve within 5 minutes (Full Activation Time). As the secondary reserve, aFRR replaces the FCR gradually after 30 seconds, the mFRR, the tertiary reserve, supports or partially substitutes the aFRR after 12.5 minutes.

To ensure the required grid frequency of 50 or 60 Hz (depending on the concerning country) the Transmission System Operators (TSO) of each country need instruments to maintain this reference value. These instruments are the balancing services. Balancing services are reactive short-term means to level out frequency deviations in the power grid. When frequency deviations occur, e.g. in consequence of a power plant outage, the Frequency Containment Reserve (FCR) intervenes automatically within seconds in the entire synchronous area to restore the balance between supply and demand. The FCR, also known as primary control reserve, is the first response to frequency disturbances. If the deviation persists, the Automatic Frequency Restoration Reserves (aFRR) subsequently replace the primary control reserve.

When Next Kraftwerke expanded its operations to Belgium in 2014, one of its goals was to convince the transmission grid operator Elia to open its automatic Frequency Restoration Reserve (aFRR) market for all technologies. aFRR, also known as secondary reserve, has historically been provided by a handful of gas fired power plants operated by two or three companies.

After two years of development, in August 2020, Next Kraftwerke and Jedlix started offering secondary reserve power (aFRR) to the Dutch grid using a pool of electric vehicles (EVs). Nick Hubbers, Jedlix, and Elias De Keyser, Next Kraftwerke, talk about their ambitions, how they realized this project, and what they learned along the way on using electric vehicles to balance the grid. Fasten your seat belts and keep reading!

The Transmission Code 2007 is a set of rules in which the four transmission system operators define the conditions to access the German electricity grid. It was first drawn up in 1998 by the Association of German Grid Operators (now "Forum Netztechnik/Netzbetrieb" as part of the VDE) in response to the liberalization of the electricity market through the amendment of the Energy Industry Act (EnWG). The Transmission Code - sometimes also known as the Grid Code - defines the conditions for access to the German grid control network, since the 1998 revision of the EnWG (Energy Industry Act) implemented the separation of electricity generation, transport, and distribution ("unbundling"). The current German version was adopted in 2007; the European Transmission System Operators’ Association (ENTSO-E) is currently preparing a European version.

The Electricity Balancing Guideline (EBGL) was created by the European Commission to establish and regulate the smooth exchange of balancing energy across the internal borders of the European Union. This guideline, which came into force as Regulation 2017/2195, sets the framework for the stabilization of the electricity grid throughout the European electricity market system. The aim is a pan-European market for system services with a harmonized market design and non-discriminatory trading of balancing energy without barriers between markets. As a result, TSOs will be able to procure balancing power more efficiently, more reliably, and cheaper.