Elia takes risk out of balancing act with Demand Response

With the increased focus on tackling climate change, especially after the recent COP21 Climate Summit in Paris, it is clear that renewable energy production will need to take an increasing proportion of our total energy supply.

Current renewable electricity production technologies (solar, wind, ocean) have inherently intermittent supply characteristics and increasing their contributions to total energy supply poses challenges to balancing the electricity grid. The traditional solution for grid balancing using peak power plants is also a declining option across Europe. However this opens up opportunities to use flexible power capacity available from industrial consumers, also called Demand Response (DR) to balance supply and demand. In addition the European Commission’s ambitious targets to reduce CO emissions through energy efficiency measures give a further strong strategic impetus to replace polluting fossil fuel peak power plants with DR.

Elia, the Belgian Transmission System Operator (TSO), is responsible for maintaining the balance between electricity production and electricity demand at all times including when power output from wind or solar facilities are fluctuating heavily.  In this context, Elia has successfully expanded various DR programmes since 2013.




In 2013 Elia opened a new pilot programme accessible to DR and over the past two years has substantially increased the flexible power capacity offered by commercial and industrial consumers via DR to balance the Belgian electricity grid.

In addition the Belgian federal regulator CREG (Commission for Regulation of Electricity and Gas), has fully embraced DR as the cheapest, cleanest and most reliable option to increase power capacity to cope with significant imbalances caused by growing Renewable Energy Sources (RES). As a consequence the total cost to society for balancing the grid has decreased as the capacity available from DR has expanded.

Convinced by the success of the DR pilot project, which was carried out by Elia with REstore in 2013, Elia has been quickly expanding the use of DR from 260 MW to over 850 MW today. As a result Belgium is now one of the leading innovation-driven countries benefiting most from various DR programmes.

“Elia has been gradually expanding the use of DR. Belgium is now one of the leading innovation-driven countries benefiting most from DR programmes”

How Elia uses DR



To balance the electricity grid through DR starts with integrating and combining flexible loads from commercial locations and production sites connected to the grid. Combining a number of these locations creates a DR ‘pool’ that acts like a virtual power plant (VPP) by reducing power consumption in response to grid imbalances. This provides an economically and environmentally more attractive alternative to ramping up peak power plants.

Elia is able to operate such VPPs, through REstore’s know-how in managing large pools consisting of multiple flexible processes at different commercial and industrial consumers across various business sectors including paper, cement, (petro)chemical firms and steel manufacturing.

When Elia detects sudden, unpredictable imbalances between power supply and demand in the electricity grid, balancing reserves are injected by activating these VPPs. To do this Elia sends an electronic activation request to FlexPond, REstore’s central server system, to which Elia’s control and dispatch centre is permanently connected. The activation request is then automatically relayed by REstore to each participating commercial and industrial consumer. Activation requests originated by Elia are sent in real-time to all control systems that manage the participating flexible load(s).

Elia, through data provided by REstore, can monitor in real-time the combined delivered power: this data clearly demonstrates the superior reliability of aggregated DR. For example, Elia has assessed the reliability of the DR capacity offered through REstore in 2015 as 100% for the Primary Reserve (R1) and 99.9% for the Tertiary Reserve (R3-DP), which is a significant improvement on the typical 95% reliability delivered by traditional peak power plant intermittent forced power outages.

As the communication to, and activation of, the available flexibility at the commercial and industrial consumer sites is achieved through a completely automated machine-to-machine communication, participation in Elia’s DR programme does not need much effort or dedicated attention from personnel on site. However, if preferred, each participating company can monitor and visualise the whole DR activation via its control processes. Activation notification messages can also be sent via SMS or email messages to operational managers. By using the automated DR concept Elia has been able to make highly efficient use of flexible power capacity with a flawless delivery performance to balance its grid in an increasingly complex operational environment with 99.6% activation success in R1 and 100% in R3DP.

For Elia the advantage of such automated DR concept is that the risk of delivery failure of balancing reserves is substantially reduced due to the range of DR programmes that REstore participates in and the diversified pool of flexible processes installed at a range of companies across several different industry sectors that it provides.

Belgium tops European DR league table



Thanks to the excellent achievements of DR aggregation, over the past two years, Elia has systematically increased the number of ancillary service programmes that are accessible to DR. As a result, Belgium is now in the top three countries in Europe in terms of ancillary services opened to DR. A recent proposal by CREG may promote Elia even further up this league table as the most innovative European TSO by enabling the deployment of future renewable energy sources while reducing overall balancing costs through DR.

At the same time participating commercial and industrial consumers greatly appreciate being able to actively contribute to grid stability and enabling a more sustainable energy system. In addition, by joining they are earning extra revenues that reduce their net energy costs. All this achieved without any extra investment to enable DR participation and no impact on their industrial performance or production output.