Artelys releases Knitro 15.1, bringing a new wave of performance upgrades and usability improvements to help you solve large-scale optimization problems faster than ever. 

More Accessible Interfaces

• New Command-Line Interface:

The new command-line interface is available through an executable named “knitro“, which accepts MPS and LP formats as well as any Knitro user options, to easily test Knitro on your instances.

• New API Functions:

The new API functions allow to manipulate model characteristics simplifying updates and KPI generation.

• Support of Linux ARM64 architectures:

All supported platforms are available on our website, check the detailed list on our dedicated page.

More Accessible Interfaces

• New Command-Line Interface :

The new command-line interface is available through an executable named “knitro“, which accepts MPS and LP formats as well as any Knitro user options, to easily test Knitro on your instances.

• New API Functions:

The new API functions allow to manipulare model characteristics simplifying updates and KPI generation.

• Support of Linux ARM64 architectures:

All supported platforms are available on our website, check the detailed list on our dedicated page.

To learn more about Knitro 15.1 and its capabilities, visit the official documentation or review the detailed release notes.

Use-cases

Discover the use-cases that transform your ideas into practical realities, building a future where technology meets real needs in an exceptional way with Knitro.

A data-driven seating system

OPTIPLACE is a seat allocation algorithm developed for OUIGO trains.The project addresses a clear need: ensuring coherent, reliable seat placement that aligns with passenger expectations, while improving seat organisation in order to free up resellable seats during periods of high demand, all while taking into account the constraints specific to rail operations.

To achieve these objectives, the module integrates directly into the reservation system. Each day, it retrieves the initial seating plan for trains at D+4, optimises it according to several criteria, and then uploads the new proposal just before tickets are sent to passengers.

The reservation system then takes over again to handle new bookings up to departure, relying on the optimised seating plan generated by OPTIPLACE.

Towards more coherent and industrialised passenger seating

Thanks to this process, OPTIPLACE ensures more coherent, smooth and balanced seating across the trainsets, while incorporating the operational preferences defined by business teams. The project therefore helps secure and industrialise a key step in SNCF Voyageurs’ operational chain.

Artelys’ contribution

A heuristic phase, generating a list of candidate seats for each booking.

A mixed-integer linear programme, selecting the optimal assignment based on the defined business objectives

Beyond developing the module, Artelys contributed to several key aspects of the project, including:

Code quality improvement, documentation and industrialisation.

Integration of new data sources.

Co-design and prioritisation of business objectives.

Integration of the module within the existing process and its interface with the information system.

Definition of a suitable technical architecture (solver choice, infrastructure sizing, etc.).

Key figures

Since its progressive deployment in July 2024, OPTIPLACE has reached full operational scale and demonstrated its effectiveness. As of the end of August 2025, more than 15,000 trains have been optimised, including nearly 10,000 that benefited from seat release, amounting to more than 138,000 freed seats in total.

Artelys Crystal Super Grid, a state-of-the-art solution dedicated to the analysis of multi-energy systems

The evaluation of the ability of an electricity system to meet demand in multiple climatic scenarios, for various configurations of planned and unplanned outage, via Monte-Carlo simulations, leveraging refined models notably of hydro reservoirs and of cascading hydro assets, and;

The evaluation of the benefits associated with developing further interconnection capacities with neighbouring countries, for various scenarios of development of generation capacities and flexibility solutions via NTC or flow-based analyses.

By leveraging the extensive set of key performance indicators integrated into the graphical user interface, our clients are able to efficiently and robustly analyse simulation results.

Finally, thanks to the capacity expansion features of Artelys Crystal Super Grid, our clients are also able to design their own transition scenarios (e.g. with different electrification levels or different technological assumptions) and to evaluate adequacy levels and infrastructure projects in these new scenarios.

Source: Artelys Crystal Super Grid, Map view and filters.

A cutting-edge micro-services solution, integrated into business workflows

Thanks to this state-of-the-art architecture, Artelys Crystal Super Grid can be integrated into our clients’ own IT infrastructure and will be able to import datasets from and export results into their own data platforms, speeding up studies and making processes more robust.

Backed by years of developement by a team composed of operations research and artificial intelligence experts, Artelys Crystal Super Grid is based on advanced optimisation algorithms, enabling the execution of complex calculation workflows with optimal performance.

If you would like to find out more about Artelys Crystal Super Grid, visit our dedicated webpage and feel free to contact our team for a demo or a trial version via this form!

The European Commission’s Directorate-General for Energy (DG ENER) selected Artelys (leader), Trinomics, and Tractebel ENGIE to study solutions for ensuring the future frequency stability of the European power system. The study report was published in August 2025 by DG ENER. 

This study analyses the role of inertia and its evolution in the context of asynchronous renewable energy deployment. This work establishes a shared understanding of inertia’s role in power system stability. 

Inertia plays a key role in frequency stability of the electricity system

The fastest reserves and defence plans require a few hundred milliseconds to activate. If frequency or Rate of Change of Frequency (RoCoF, frequency’s derivate) exceed critical thresholds during this interval, the system risks collapse (blackout) due to the tripping of assets for their own protection. 

Inertia immediately limits RoCoF, independently of any control system, thereby preventing critical RoCoF levels from being reached before any remedial action can take place. 

Workshop Assessment of Policy Options for Securing Inertia – May 6, 2025

Grid inertia is set to decline sharply in the long term without intervention

Historically, inertia relied on the natural adjustment provided by extracting power from the kinetic energy of synchronous machines, stored in rotating machines.

With the energy transition, an increasing share of assets are connected to the grid via power electronics inverter-based resources (IBRs: photovoltaic power plants, wind turbines, batteries, …) and account for a growing proportion of instantaneous generation, replacing synchronous thermal generation. These assets are traditionally equipped with grid-following inverters and thus do not provide inertia (although grid-forming technologies associated to energy storage can). 

A significant decline in system inertia is therefore anticipated across the European power system around 2030 as analysed by ENTSO-E, with needs increasing towards 2040-2050. 

Workshop Assessment of Policy Options for Securing Inertia – May 6, 2025

Securing adequate inertia levels is a technical, regulatory and economic challenge of growing importance as Europe undertakes its energy transition

Defining the framework for inertia service provision is thus necessary for establishing the long-term foundations of the European power system’s future resilience. To this end, it is necessary to:

Assess the evolution of the European power system’s inertia requirements based on the risk levels deemed necessary to cover, and define inertia targets to securely integrate IBRs into the grid in the short- to long-term; 

Establish common parameters for inertia products in the short-term, for instance through the revision of the Requirements for Generators (RfG), in a technology-neutral manner; 

Plan inertia provision and local stability services (voltage and short-circuit levels) in an integrated manner, as solutions can be shared; 

Examine the costs, benefits, and limitations of regional inertia exchanges for the medium-long term.

Upper-bound estimates for the long-term cost of providing inertia services reach up to €4 billion per year, though significant uncertainties remain, and solutions may prove less costly. 

Enabling renewable assets and storage to effectively and rapidly contribute to maintaining the European power system’s inertia, as well as to delivering local system services, is key. 

The report contains an in-depth analysis of inertia, based on a literature review organised by Artelys and feedback from stakeholders obtained through a webinar and interviews

These analyses notably covered the challenges and risks associated with frequency stability in the electricity system, the definition of inertia, the specification of the physical quantities required to ensure this stability, the fundamentals determining inertia requirements and the definition of associated services. Artelys also analysed the foreseeable evolution of inertia requirements with the energy transition, as well as the existing inertia and fast reserve markets. 

Discover the full report here.