Hybrid electricity storage

Grid operator TenneT and energy start-up S4 Energy have put a new type of energy storage into operation in Almelo. The combination of batteries and a flywheel is ideally suited to tackle the challenges of the energy transition. Batenburg Energietechniek supplied 4 transformer substations to support the flywheel.

The four transformer substations consist of two compact substations and two accessible substations. The compact substations house a medium-voltage installation with a transformer and a low-voltage system. The other two accessible transformer substations comprise a transformer substation and a transformer substation with the necessary equipment.

Supplied in total:

• 2 compact substations
• 2 accessible transformer substations
• 2 medium-voltage systems
• 2 transformers
• 2 low-voltage systems

Energy security in the transition to wind, solar and storage

For TenneT, 50 is a sacred number. This is the AC frequency that the grid operator must monitor at all costs. Large rotating gas and steam turbines now play the main role in this, but classic gas and coal-fired power stations will disappear in time.

‘These will be replaced by several smaller energy producers, especially solar and wind farms,’ says Danny Klaar, manager at TenneT. These new energy sources are not controllable like gas and coal-fired power plants, so TenneT has to change the way it monitors frequencies.  This can be achieved by using batteries with hot water boilers,  for example; however, compensating for thousands of large frequency fluctuations eats away at the lifespan of this technology.

Wear-free frequency monitoring

‘Our flywheel technology delivers high powers instantly, without any loss of capacity,’ says Dominique Becker Hoff, Project Director at S4 Energy. Although the flywheel delivers high power, its energy capacity is low. To compensate for this, S4 Energy developed a hybrid system for TenneT that combines the best of ‘spinning masses’ and the latest battery technology. Becker Hoff: ‘During long-term variations, we switch on the batteries. Together, they complement each other perfectly.’

The clever interplay makes the batteries last much longer. Despite intensive use, Becker Hoff guarantees a system life of more than 10 years.

Source text:  wattisduurzaam.nl  Source photo:  aaVISIE