Interoperability is the ability of a product or system to cooperate with other products or systems in terms of sharing resources. This term is suited to address a wide range of uses, with [1] covering nineteen different types of interoperability applications within energy sectors.

The growth of renewable power generation will create an increasing demand for flexibility. So-called “cross-sector integration” [2,3] can provide cost-effective ways to increase the flexibility of the energy system but will require significant cooperation and information before it can be implemented.

Interoperability features implemented by technology vendors for network implementations bring the following added values to system integrators and end users [4]:

• Benefits to the electricity grid operators:

  • Optimising resources to maintain and reinforce the networks effectively and at low cost, thanks to increased visibility of real-time demand, enabling improved spatial planning by identifying locations in the electricity grid that are most under pressure.
  • Improving the electricity system reliability by enabling early fault detection, and the optimal operation of existing network infrastructures thanks to the digital integration of sensors and monitors in the existing network.
  • Improving grid stability and reducing the risk of system blackouts thanks to monitoring or remotely accessing behind the meter resources such as solar photovoltaic (PV) or smart electric vehicle (EV) charging in emergency situations.
  • Maximising demand flexibility by optimising infrastructure outputs when loads are temporarily shifted from high to lower demand, thus increasing the longevity of existing network infrastructures.
  • Anticipating peak demand or excess power generation via load shifting with market signals, thus favouring interoperable space heating and cooling to reduce the impact on local distribution grids.
  • Improved communication of physically and digitally integrated network devices.

• Benefits to electricity consumers:

  • Increasing the power system flexibility to automate shifting demand from peak prices to off-peak prices and favour energy arbitrage, reducing energy bills.
  • Shifting consumption towards times when energy production is at its highest for sites using solar panels in self-consumption mode.
  • Increasing customer skills with minor interventions to optimise household energy consumption using consumer preferences and market signals.
  • Improving EV charging experience from the public network with reduced proprietary connectors, improved digital payment platforms, and an ability to ‘roam’ internationally.
  • Optimising existing electric transmission and distribution grid infrastructures by delaying or avoiding reinforcement expenditures and most probably reducing the need to socialise costs related to grid adaptations.

• Benefits to business and economic growth:

  • Creating environments to launch new business models based upon secure, anonymised, real-time consumption data maximising the electricity system efficiency.
  • Eliminating proprietary barriers from devices controlled by the vendor under trade-protected patents, thus opening market access to reduce monopolistic behaviour and increase competition.
  • Using single agreed standards to support the scalability and faster deployment of new business models related to decarbonisation and their implementation within many jurisdictions.
  • Offering benefits to electricity grid operators, electricity consumers, and businesses, while increasing symbiotic relationships between and among market players to design and provide new energy services.

Interoperability efforts drive innovation, leverage emerging technologies, and optimise performance through a culture of collaboration and continuous improvement standards. There are four major enablers to implementing interoperability as stringent technology development constraints:

• Reaching an acceptable maturity level for the actual state of the company system-of-interest [5].
• Testing interoperability in accordance with the expected maturity level [5] from the ongoing R&D project about “Interoperability Network for the Energy Transition” (Int:NET).
• Ensuring compliance with existing standards, their evolution, and the definition of new standards.
• Describing new business processes using reference models at a meta level, which allows different national implementations but guarantees that all processes can be interpreted the same way across Europe.

Pursuing an unprecedented digital and green transition remains a challenging task for European TSOs, which operate the most complex legacy electricity system in the world. Nonetheless, they have introduced interoperability in the Common Grid Model Exchange Specification (CGMES), an IEC technical specification (TS 61970-600-1, TS 61970-600-2) based on the IEC Common Information Model (CIM) family of standards.

The specification was developed to meet the necessary requirements for TSO data exchanges in the areas of system development and system operation. In this scenario, the agents – the modelling authorities – generate their individual grid models (IGMs) that can be assembled to build broader common grid models (CGM). Boundaries between IGMs are well defined, whereby the boundary data is shared between the modelling agents and developed to meet the necessary requirements for TSO data exchanges.

Finally, the Int:NET project aims to establish an open, cross-domain dedicated community that brings together all relevant stakeholders in the European energy sector. They are jointly working on an agreed maturity model, which will be the key enabler to develop, test, and deploy interoperable energy services [5,6].

Data flows between sectors according to the concept of interoperability are addressed in the Data Governance Act [7], covering:

• a framework to enhance trust in voluntary data sharing for the benefit of businesses and citizens;
• principles of data spaces across sectors that will exchange energy data with other sectors such as mobility and industrial manufacturing, as well as health and agriculture.

A Smart energy Grid Architecture Model (SGAM) model was shaped by the CEN-CENELEC-ETSI Smart Grid Coordination Group in 2014. It is a three-dimensional architectural framework that can be used to model interactions – mostly exchanges of information – among different entities located within the smart energy arena [8].

The smart meter implementation and daily data delivery in the EU27 member states illustrates how several organisations of the electricity value chain can work together seamlessly under different regulations, electricity networks, and electricity generation profiles.

A detailed description of the involved methodology to test the challenging interoperability issues of complex control and protection systems is described for HVDC grids in [9]. It allows pinpointing further R&D needs on interoperability approaches:

• Improved methodologies to quantify the functional requirements of complex innovative power systems: past vendor studies might have focused on specific implementations, and thus general methodologies need to be developed to define system studies required to quantify the functional requirements of components.
• Standardisation of validation tests in view of de-risking interoperability issues: new methodologies should be developed to define the necessary dynamic studies in terms of validating the interoperability level of complex systems or components.
• Specifications of the performance ratings of components involved in complex innovative power systems: new methodologies might be developed to specify the ratings of components involved in complex interactions of controls or protections.
• Communication architecture and protocols: developing new communication protocols or extending IEC 61850 standards might be necessary to meet bandwidth/speed for selective control or protection.
• Simulation models and information exchange: a classification of appropriate modelling tools and data inputs is needed to provide guidelines on carrying out necessary studies using appropriate models.
• Extensive use of hardware-in-the-loop (HIL) to validate the interoperability of tentative vendor modules and/or solutions at appropriate costs.

BRIDGE [10] is a European Commission initiative that unites Horizon 2020 and Horizon Europe Smart Grid, Energy Storage, Islands, and Digitalisation Projects. It aims to create a structured view of cross-cutting issues that are encountered in the demonstration projects and might constitute an obstacle to innovation.

A working group on data management has worked on data handling, including the framework for data exchange and related roles and responsibilities. It has issued a report entitled “European (energy) data exchange reference architecture 3.0” [11]. Recommendations are made to implement the data exchange reference architecture (DERA) 3.0 in line with other standardisation processes dealing with data interoperability in the smart grid area.

Challenges to reaching the scope are currently related to achieving an appropriate level of maturity. The core of the maturity model developed in Int:NET [5] comprises the following components:

• Categories
• Dimensions
• Maturity level
• Questionnaire

The framework of the int:NET interoperability maturity model is visualised in the radar diagram below using a fictitious application example.

• Categories at the outermost edge represent groupings of associated dimensions labelled near the centre.
• From the centre, the areas to which maturity levels are assigned are defined in an ascending order.
• Each dimension can be assigned to a maturity level by marking the area.
• This maturity model uses categories as a grouping tool for the relevant topics within the energy sector.

The technology is in line with milestone “Demonstration of interoperability of HVDC converters” under Mission 2, milestones “Vendor agnostic architectures for system control applications” and “Vendor agnostic modules & tools for system control applications” under Mission 4, milestone “Definition of ICT requirements and standards to collect data for flexibility markets” under Mission 5 and milestone “Standards for cross-sector interoperability and data exchange” under Mission 6 of the ENTSO-E RDI Roadmap 2024-2034.

Examples

TRL 9 for projects as MCCS to be reached by pioneer TSOs in 2026.
TRL 8 for Int:NET results to be achieved in April 2025.

1. D. Mee, “An Introduction to Interoperability in the Energy Sector,” 2018.

2. M. Robinius et al., “Linking the Power and Transport Sectors—Part 1: The Principle of Sector Coupling,” Energies, vol. 10, no. 7, p. 956, 2017.

3. N.Putkonen, “How the future energy system will benefit from sector integration”, VTT, 2023.

4. B. Reidenbach et al., “Towards net-zero: Interoperability of technologies to transform the energy system,” OECD Going Digital Toolkit Notes, No. 24, OECD Publishing, Paris, 2022.

5. R. Kuchenbuch et al., “D2.1 Interoperability Maturity Model Framework and Background”

6. https://cordis.europa.eu/project/id/101070086

7. Regulation (EU) 2022/868 of the European Parliament and of the Council of 30 May 2022 on European Data Governance.

8. R. Kuchenbuch et al., “Quality properties of IEC 62559 use cases and SGAM models,” Energy Informatics, vol. 6, supplement 1, p. 38, 2023.

9. M. Wang et al., “Multi-vendor interoperability in HVDC grid protection: State-of-the-art and challenges ahead,” IET Generation, Transmission & Distribution, vol. 15, p. 2153, 2021.

10. BRIDGE, “Smart energy systems research and innovation”.

11. J.M. Couto et al., “European (energy) data exchange reference architecture 3.0”, Publications Office of the European Union, 2023.

12. ENTSO-E, “ENTSO-E Research, Development, & Innovation Roadmap 2024-2034”, ENTSO-E.

13. MCCS, “Developing the new grid control system for a successful energy transition”, MCCS.