The objective: preventing power failures
The provision of what is known as balancing energy serves to secure the power supply. It is used when there is either excess demand or excess supply on the power market. To be able to compensate variations in the power market, the large Transmission System Operators must provide between 5,000 and 6,000 MW of balancing energy (in total) at all times.
And this applies to both positive and negative balancing power, so that both excess demand and excess supply can be compensated. With the aid of this reserve, variations can be equalised within seconds (primary reserve), five minutes (secondary reserve), fifteen minutes (minute reserve) or hours (hour reserve).
The renewables "control" too
The operators of small plants are now gaining importance, particularly in the minute reserve area. Since the 1st January 2012, there has been the possibility of compensating network variations caused by the feed-in of renewable energy with likewise renewable energy.
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For example, an excess in photovoltaic power can be compensated by a simultaneous reduction in the operation of a biogas plant (negative balancing energy).
Interconnected small plants form large scale virtual power plants
Complete compensation of each other by renewables is not currently realistic. Although their share of negative balancing energy is currently approximately 20%, further expansion is needed. A particular feature must also be noted: In order to be able to act on the balancing energy market, a plant operator must have a potential power capacity of at least 5 MW. As small plants cannot generally manage such a high potential, they must interconnect with other small plants and form what are known as large scale virtual power plants.
Critical components of the technologies needed for this are available from SAE.
SAE technology partner:
Next Kraftwerke GmbH