The energy transition brings opportunities, but also challenges - such as imbalance on the electricity grid. This occurs when electricity supply and demand are not balanced, which can lead to additional costs and risks. Scholt Energy helps restore this balance by smartly deploying flexibility from connected assets such as solar and wind farms, batteries and controllable electrical processes. But what exactly does imbalance mean? And how do we contribute to a more sustainable energy network? In this blog, we explain.
The European power grid works optimally at a frequency of 50 Hz. Various factors can disrupt supply and demand, such as changing weather conditions or the failure of a large power plant. Electricity shortages - when demand exceeds supply - can result in blackouts or even outages. Conversely, an energy surplus, such as from a spike in renewable power generation, can overload the grid and cause damage to equipment and infrastructure.
To restore balance, grid operator TenneT uses different balancing markets. Each type of reserve plays a specific role in correcting imbalance:
FCR (Frequency Containment Reserve): This is also known as the "first line of defense." This reserve power responds within seconds to correct small grid frequency deviations (such as a drop below 50 Hz). It helps cushion the initial impact of a disturbance and is often provided by batteries or other fast-response flexible resources.
aFRR (Automatic Frequency Restoration Reserve): If the imbalance persists longer, aFRR takes over. This reserve power stabilizes grid frequency within minutes by automatically supplying more or less electricity. It is intended for medium-term corrections and brings the frequency back to the desired level of 50 Hz.
mFRR (Manual Frequency Restoration Reserve): During prolonged or larger disturbances, mFRR comes into action. This emergency power is manually activated by TenneT and can be deployed for hours. Examples are large industrial processes that temporarily use less or more energy, such as cold stores, CHPs and NSAs (demand response) or wind and solar farms that are shut down for a longer period of time (curtailment).
Adjusting the grid by TenneT has financial consequences. The causer of imbalance pays costs, while the resolver receives income. Prices on these imbalance markets fluctuate more strongly and are often considerably higher than on regular energy markets. How high these costs are depends on the timing and severity of the imbalance.
These costs are usually passed on to end users, which can hit companies with high energy consumption particularly hard. This encourages them to invest in solutions that help reduce imbalance, such as energy storage or demand response.