Balancing Energy Market
Description of Balancing Energy Market
Fluctuations between the inflows and outflows of electricity from the grid must be constantly
balanced; this is done by raising or lowering the output of control reserve at power plants on
short notice. A differentiation is made between the control reserve resources: primary control
reserve, secondary control reserve and tertiary control reserve (minute reserve). These control
reserve resources differ as regards the speed of activation and change. Primary and secondary
control reserve is automatically called from power plants capable of producing control reserve. The
tertiary control reserve is tapped by making telephone requests to suppliers.
Primary control reserve must be available within 30 seconds and secondary control reserve
within five minutes in the required volumes as requested. Since January the 1st 2010, the provision
of primary control is organised via weekly tender (www.regelleistung.at). APCS itself is not
involved in the provision and settlement of primary control reserve. Secondary control reserve is
provided by Verbund in the balance area APG.
Tertiary control reserve (minute reserve) is tapped by sending instructions to suppliers.
These are used in cases in which secondary control reserve has been flowing for a longer period
especially after power plant outages and serve to replace secondary control reserve and release
capacities for new power procedures. Tertiary control reserve is usually tapped for scheduled
supplies at every full quarter of an hour and must therefore be fully available for activation or
de-activation within 15 minutes.
Auction mechanism
The organization of the tertiary control reserve market is another major function of the balance group model: APCS organizes – similar to an exchange – a marketplace on which market participants can place bids for buying and selling energy volumes; this day-ahead market is open daily until 16:00 hrs – afterwards, the so-called merit order list is generated based on the supply curve and sent to the system operator. The system operator call the required volumes of tertiary control reserve by telephone – with a ten-minute advance notice – from this merit order list.
Balancing energy volumes sourced from secondary control reserve or UCTE exchange are procured at weekly tender procedures and delivered back to APT as a payment in the form of a redelivery program.
To secure sufficient tertiary control reserve volumes, so-called Market Makers are licensed to act in the balance area APG – apart from the balancing energy suppliers; these Market Makers guarantee sufficient volumes for the tertiary control reserve market at weekly Market Maker tenders and thus ensure a sufficient supply of energy to the system.