The Iberian energy market is undergoing a major transformation. Operador del Mercado Ibérico de Energía (OMIE) is transitioning to 15-minute settlement periods, a shift that will significantly reshape trading and operations across Spain and Portugal. This change increases the complexity of market participation, moving from 24 hourly trading rounds to 96 sub-hourly intervals. While other countries in Europe retain 60-minute settlement periods, market participants in the Iberian Peninsula — including utilities, retailers, independent power producers (IPPs), and financial traders — must quickly adapt to the discontinuation of hourly products in favor of more granular 15-minute offerings. To support this transition, Amperon has launched forecasting solutions that align with these new market structures while maintaining its industry-leading accuracy.
The rapid growth of solar photovoltaic (PV) and wind power in the Iberian Peninsula has profoundly influenced short-term market behavior. This surge in renewables has coincided with heightened price volatility, including an increase in very low price (<1€/MWh) and zero price hours. The current hourly settlement structure is insufficient to capture the intermittent and rapid fluctuations in generation, particularly during morning solar ramp-ups and evening ramp-downs.
The existing hourly Market Time Units (MTUs) market construct has led to substantial imbalances, resulting in market inefficiencies and costly penalties for asset owners. Transitioning to a 15-minute MTU enables the market to more accurately capture generation variability, reduce imbalance costs, improve liquidity, and better accommodate growing carbon-free generation and load flexibility.
Anticipating market evolutions like OMIE's shift, Amperon invested in developing accurate and granular forecasts for sub-hourly market time units including grid demand, grid net demand, and asset-level solar PV and wind solutions. Our forecasts provide market participants with the tools and precision they need to stay competitive and mitigate risks in more granular market structures.
Amperon's forecasting models are built on a leading hybrid regression/ML approach and data integrations that consistently deliver industry-leading accuracy. Our sub-hourly methodology is built on our forecasting principles:
Based on these principles, we’ve demonstrated differentiated accuracy through our approach to weather ensembling and machine-learning based load and generation models.
Weather forecasts play a critical role in predicting generation and load. Relying on a single weather source can increase forecast uncertainty, but Amperon mitigates this risk with a ML-driven weather ensemble model. By dynamically weighting inputs from multiple weather vendors, the model continuously evaluates each vendor’s hourly accuracy and adjusts their influence accordingly. This approach reduces the impact of errors stemming from any single provider and enhances the overall reliability of the final prediction.
Amperon’s machine learning models are specifically designed for sub-hourly load and generation forecasting to better capture the inherent variability and volatility of energy systems. These models leverage high-frequency data and advanced feature engineering to detect rapid changes in demand and generation. By incorporating sub-hourly inputs, the models adapt to granular fluctuations, providing more accurate and responsive forecasts that support precise operational and financial decisions.
We’ve achieved strong forecast accuracy for large solar PV assets, as reflected in our capacity-normalized mean absolute error (cnMAE) results below for individual solar PV assets from 2024 to Present:
Customers can visualize and evaluate our sub-hourly forecast accuracy from our user interface. Here is a screenshot from of the 80MWdc solar asset on January 12, 2025 and the 5-min granularity forecast evaluation.
The move to 15-minute settlement periods presents both challenges and opportunities. With Amperon's cutting-edge forecasting solutions, you can navigate the increased complexity, reduce costs, and capitalize on new market opportunities. Contact us to learn how we can support your transition to the new OMIE market structure.
