Ancillary services, also known as frequency control reserves, are the \u201crapid response force\u201d of the electricity grid. Their role is to continuously maintain the balance between electricity generation and consumption at every second.<\/p>\n
This balance is essential to keep the grid frequency in the European interconnected system stable at 50 hertz (Hz). Even the smallest deviations can threaten grid stability. With the increasing integration of volatile renewable energy sources such as wind and solar, the importance of ancillary services is steadily growing.<\/p>\n
When the actual grid frequency deviates from its nominal value of 50 Hz, ancillary services are activated in a three-stage cascading system. Transmission system operators (TSOs) procure the required capacity on dedicated balancing power markets.<\/p>\n
The first line of defense. It is automatically and fully activated within 30 seconds in response to frequency deviations. Its purpose is to immediately stop the deviation and stabilize the grid frequency.<\/p>\n
The second stage. It is centrally activated by TSOs and must be fully available within 5 minutes. Its function is to relieve the primary reserve and restore the grid frequency precisely back to 50 Hz.<\/p>\n
The third and slowest reserve. It is manually activated by TSOs and used to replace secondary reserves.<\/p>\n
According to the German Federal Network Agency (Bundesnetzagentur), mFRR must be delivered with a lead time of up to 7.5 minutes and is typically activated for at least 15 minutes at a constant output level. It serves as an economic reserve for longer-lasting imbalances.<\/p>\n
Battery Energy Storage Systems (BESS) are technologically superior to conventional power plants in providing ancillary services, especially the economically attractive Frequency Containment Reserve (FCR).<\/p>\n
These advantages make BESS one of the most efficient and important participants in the ancillary services market, which represents a core revenue stream in their operation.<\/p>\n
The 50 Hz grid frequency is the central synchronizing parameter of the European power system. Electricity generation and consumption must always remain balanced, as electrical energy can only be stored in the grid to a very limited extent.<\/p>\n
The grid frequency directly reflects this balance: if generation exceeds demand, frequency rises; if demand exceeds generation, frequency falls.<\/p>\n
If deviations become too large, protective systems automatically disconnect power plants or grid sections. This can trigger cascading failures and lead to large-scale blackouts. Ancillary services counteract these deviations and are therefore essential for system stability and supply security.<\/p>\n
Technically yes, but economically there are clear focal points. BESS primarily demonstrate their strengths in fast-response ancillary service products.<\/p>\n
Yes, for symmetric provision of primary reserve (FCR), this is the optimal operating strategy. A state of charge (SOC) of around 50% ensures that the system can both inject and absorb energy equally.<\/p>\n
The following minimum power requirements apply for participation in the ancillary services market:<\/p>\n
Smaller systems can participate through aggregation via a pool operator.<\/p>\n
No. The revenue model in the ancillary services market differs depending on the specific reserve product.<\/p>\n
For Frequency Containment Reserve (FCR), revenue is based exclusively on a capacity payment for providing and maintaining availability. This payment is independent of any actual activation.<\/p>\n
For Secondary Control Reserve (aFRR) and Tertiary Control Reserve (mFRR), the revenue model consists of two components:<\/p>\n
As a result, a BESS already generates revenue simply by being available as reserve capacity. In the case of FCR, this availability payment is the sole source of income.<\/p>\n
<\/p>\n
<\/p>\n","protected":false},"excerpt":{"rendered":"
Ancillary Services \u2013 The Heartbeat of the Power Grid Ancillary services, also known as frequency control reserves, are the \u201crapid response force\u201d of the electricity grid. Their role is to continuously maintain the balance between electricity generation and consumption at every second. This balance is essential to keep the grid frequency in the European interconnected […]<\/p>\n","protected":false},"author":29,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"white-header.php","meta":{"_acf_changed":false,"_et_pb_use_builder":"","_et_pb_old_content":"","_et_gb_content_width":"","inline_featured_image":false,"footnotes":"","_links_to":"","_links_to_target":""},"class_list":["post-64894","page","type-page","status-publish","hentry"],"acf":[],"_links":{"self":[{"href":"https:\/\/greentech.energy\/en\/wp-json\/wp\/v2\/pages\/64894","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/greentech.energy\/en\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/greentech.energy\/en\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/greentech.energy\/en\/wp-json\/wp\/v2\/users\/29"}],"replies":[{"embeddable":true,"href":"https:\/\/greentech.energy\/en\/wp-json\/wp\/v2\/comments?post=64894"}],"version-history":[{"count":3,"href":"https:\/\/greentech.energy\/en\/wp-json\/wp\/v2\/pages\/64894\/revisions"}],"predecessor-version":[{"id":64904,"href":"https:\/\/greentech.energy\/en\/wp-json\/wp\/v2\/pages\/64894\/revisions\/64904"}],"wp:attachment":[{"href":"https:\/\/greentech.energy\/en\/wp-json\/wp\/v2\/media?parent=64894"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}