An important prerequisite for the secure operation of the transmission grid is the balance between electricity generation and consumption. Every second, the same amount of energy must be fed into the grid as is consumed, so that the frequency always remains constant at 50 Hertz. When unforeseen oscillations occur, Swissgrid uses control energy: it commissions power plants to increase or decrease their production.
The transmission system operators in Europe take a three-tiered approach to the use of control energy: a few seconds after an event, such as an unplanned outage of a power plant, the primary control reserves are deployed. Within a few minutes, these are replaced by the secondary control reserves, which restore the frequency of 50 Hertz. If the imbalance lasts longer than 15 minutes, the grid control rooms can manually activate tertiary control reserves.
Swissgrid commissions power plants to provision this reserve so that it is always available. The company procures the three different frequency control products in control energy markets set up specifically for this purpose, with the capacity required being put out to tender on internet platforms. The power plants submit their bid at a certain price on these platforms. If the contract is awarded, the power plants must be able to immediately provide the offered capacity within a certain period. Swissgrid remunerates the power plants for this service. Additional remuneration is paid to power plants if secondary or tertiary control energy is actually required.
Swissgrid is constantly further developing the control energy markets. The aim is to increase the number of bidders and competitors and thus the liquidity in the markets. Swissgrid’s ongoing development activities have made it a pioneer in Europe, something which was once again apparent in the development of an international cooperation for the procurement of primary control power and the introduction of control pooling.
The control power markets are heavily influenced by the transformation of energy systems. Swissgrid is actively tackling developments such as the energy reform and digitalisation, as is shown by the new Equigy project.
Swissgrid is also heavily involved at a European level. The liberalisation of the electricity market adopted by the EU is leading to innovations in the control power markets. Swissgrid participates in numerous European committees to ensure that it remains involved in international cooperation activities and can work closely together with its partners in Europe.