"Bringing in GAMS’ team was the right decision. With their expert knowledge, they helped us bring our state-of-the-art model up to the best industry standards. The before and after numbers showed an impressive difference. Thanks to their work, we now have a smooth pipeline, and a reliable and fast-performing model."
Area: Energy
Problem class: LP
Technologies: GAMS
Austrian Power Grid (APG) has the statutory and therefore social mandate to provide Austria with a secure supply of electricity and is thus responsible for the country’s security of supply. With its highly qualified staff, APG has been ensuring a secure electricity supply across the country, from Lake Neusiedl to Lake Constance, for decades. The stable electricity supply in Austria is based on a strong, high-capacity transmission grid, a mix of power plants comprising many wind, hydro, and pumped storage plants, additional reserve power plants, and APG’s intensive, ongoing coordination with national grid operators and European transmission system operators.
As the national Transmission System Operator, APG is dedicated to ensuring a reliable and sustainable energy supply by strategically planning and developing its grid assets. This involves coordinating both the refurbishment of existing infrastructure and the construction of new assets in close collaboration with national initiatives and international processes such as the Ten-Year Network Development Plan (TYNDP). Through this coordinated approach, APG aims to integrate advanced technologies and innovative grid solutions, promote energy market harmonization, and support the broader objectives of the European energy transition while maintaining system resilience and operational excellence.
To achieve these objectives, APG has developed an advanced GAMS model that optimizes energy flow—including distribution, storage, and trade—over the span of an entire year. Based on extensive data sets, the model is structured as a large-scale linear program that is decomposed into smaller, weekly sub-models using a rolling-horizon approach. This dynamic methodology enables APG to manage evolving scenarios by breaking the problem into smaller, overlapping intervals and solving them iteratively.
Despite these advancements, challenges remained. Model generation and solver times exceeded desired limits, and some instances resulted in infeasibility, preventing the establishment of a consistent annual solution. Consequently, APG’s System Development Unit faced time-consuming efforts to identify and resolve these inconsistencies, leading to missed opportunities for energy optimization.
Our team of experts collaborated with APG to conduct a comprehensive review and refactoring of their market optimization pipeline. Focusing on improving model generation time, solver efficiency, and stability, the results were truly impressive. Following our consulting project, APG achieved significant advances in every metric, and a substantial impact in both the efficiency and reliability of their model.
Prior to partnering with GAMS, several model instances were infeasible, which limited APG’s ability to solve all scenarios to optimality. A thorough analysis revealed that numerical issues—specifically, inconsistencies in the rounding of input data—prevented the solver from finding optimal solutions within the default tolerances. Once these issues were identified, our GAMS experts achieved complete stability across all model instances, ensuring every scenario can now be solved optimally.
Our team also realized a significant reduction in total model-solving time; some instances are now solvable in just 225 seconds, compared to over 900 seconds previously. These improvements stemmed from two key areas: model generation and solver time. Model generation times were reduced by up to 30%, while solver times decreased by as much as 70%.
Lastly, the refactored model demonstrated considerably more efficient memory usage, with a significantly reduced high-water mark, i.e. peak memory requirement. Memory consumption was reduced by approximately 80%, from over 42 GB to under 9 GB. This enhancement not only boosted overall performance but also enabled the system to handle large-scale problems more reliably, particularly on shared computer resources.
Our collaboration with APG is a data-driven success story that underscores the powerful impact of GAMS’ targeted consulting services on transforming complex, large-scale optimization models. The partnership has led to substantial improvements in system performance and resilience, clearly demonstrating the considerable benefits of applying expert optimization strategies to modern energy challenges.
“Bringing in GAMS’ team was the right decision”, said Valentin Wiedner, Teamlead of System Modelling at APG. “With their expert knowledge, they helped us bring our state-of-the-art model up to the best industry standards. The before and after numbers showed an impressive difference. Thanks to their work, we now have a smooth pipeline, and a reliable and fast-performing model. Their proactive approach and commitment significantly contributed to the timely and high-quality completion of our project. We are highly pleased with the results and greatly appreciate the professional and collaborative partnership.”
Throughout the project, GAMS provided deep technical insight and industry-leading expertise to address key performance barriers. By meticulously refining model generation processes and optimizing solver efficiency, GAMS ensured that the optimization pipeline not only met but exceeded top industry standards. This technical enhancement has resulted in a streamlined pipeline and a system that consistently delivers rapid, optimal solutions. The upgraded model now solves every instance within shorter time frames and without the computational inefficiencies that once hampered performance.
Furthermore, this initiative has enhanced APG’s operational readiness, equipping them with a robust foundation to execute their regular system development processes and strategic planning with absolute confidence. The collaboration has not only improved immediate performance metrics but has also contributed to building a more resilient and future-proof system, positioning APG at the forefront of energy optimization and innovation.