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Connected Energy and Engie teamed up on a battery energy storage system to test whether generating revenue from grid balancing can work abroad.

  • Industry:  Energy
  • System no:  1
  • Power:  150kW
  • Capacity:  90kWh
  • Application:  Revenue generation
  • Functionality:  Adapting systems to suit Dutch Aggregators


ENGIE (known as GDF Suez prior to April 2015) is a French multinational electric utility company, headquartered in La Défense, Courbevoie, which operates in the fields of electricity generation and distribution, natural gas, nuclear and renewable energy.

The company is a component of the Euro Stoxx 50 stock market index. Engie wanted to prove that revenue generation by providing grid balancing services was viable in the Dutch energy market.

The Brief

Energy providers’ requirements vary from country to country. With slightly different ways of working, it is very difficult to create a ‘one-size-fits-all’ solution.

To test how Connected Energy could replicate our success in the UK’s grid balancing market we partnered with Engie, to explore how this concept would work with Dutch energy providers.

If proven, it would open the market up for greater levels of renewable energy adoption by mainstream markets, with revenue generation acting as a form of incentivisation.

The energy landscape has shifted. The debate isn't just about how much energy we use, it's also about when we use it.

Matthew Lumsden, CEO, Connected Energy

The Solution

Connected Energy supplied Engie with an E-STOR system specifically designed to provide dynamic firm frequency response services to the Dutch grid operator TenneT. The system is controlled by Engie’s in-house aggregator.

A battery energy storage system (BESS) can be used to help balance the grid, by storing and discharging energy when its needed, improving energy resilience. As we move towards increasing the number of renewables in our power generation mix, the ability to balance this with flexibility elsewhere on the power system will become increasingly important.

The Dutch grid Grid buys energy in large blocks, typically by the megawatt (MW). If a BESS provides less than 1MW, it can’t individually supply the grid. An energy aggregator is a way for several smaller assets in the same area to group together to sell grid-balancing solutions. The aggregator is the interface to the Grid operator and the route to market.

They also calculate how much revenue is paid to the owners of each asset. In this way, aggregation also provides a degree of security to Grid operator – if there is an issue with one of the assets in the group, other assets can step up and provide that energy, ensuring there is no disruption of service. After all, there is strength in numbers.

The control architecture that makes this possible has been designed to work seamlessly with aggregators to provide the rapid response times required by Transmission System Operators (TSOs) procuring grid balancing services. The control system ‘sits’ within the E-STOR and an HMI enables control parameters to be adjusted on-site.

The system was required to pass the local grid operator’s standard pre-qualification tests to provide the services. The E-STOR system was integrated with Engie’s energy aggregator and is now providing non-stop frequency response services and generating revenue for Engie.

The system has been developed with a meeting space in the container and windows so that visitors can see the technology in operation.

Next Steps

Now installed, Engie was provided with proof of concept. The system seamlessly charges and discharges energy when needed by the grid, providing invaluable balancing services and receiving revenue in return.

Let's connect!

Get in touch with our team to discuss whether battery energy storage can work for your business, and how we can offer a free feasibility study.