Annual operational data for the 10 MWe ELLO Fresnel concentrated solar power plant

This data article introduces a unique yearly dataset from the 10 MWe eLLO Concentrated Solar Power (CSP) plant, a commercial-scale Linear Fresnel Reflector (LFR) facility using Direct Steam Generation (DSG) and steam storage, located in Llo, France. The dataset, collected via a supervisory system, includes real-time operational data from 124 sensors distributed across the plant, categorized into seven types: meteorological, solar field (east/west), turbine/aero-condenser, feedwater, electricity production and storage system. Those data were collected under standard operational conditions at two different acquisition times:•a 24-hour snapshot (from July 16th, 2025, 04:00 to July 17th, 2025, 04:00) recorded with a 10-second interval.•a year-long variable data (from January 1st, 2025, 00:00 to January 1st, 2026, 00:00) with a 1-hour interval. Erroneous data were flagged as NaN, resulting in 338 usable days for 2025.The dataset is organized into three sheets:•"Description": metadata (sensors IDs, variables, units, annotated schematics).•"24-hour period": data for all variables over the 24-hour period described earlier.•"Year 2025″: data for all variables over the year 2025.This is the first open yearly dataset for a commercial LFR-DSG plant, enabling experimental validation of numerical models, simulations of part-load operation, thermal storage dynamics, and efficiency, as well as optimization of plant sizing, operational strategies, and techno-economic analyses. A reference case study for researchers, engineers and industrial stakeholders in a field where real-world data are scarce.