Negative day-ahead quarter-hours in Hungary, October 2025 to September 2026

Every quarter-hour with a negative day-ahead price in the Hungarian bidding zone during the first year of 15-minute day-ahead trading (1 October 2025 to 30 September 2026), with the public solar, wind, nuclear, load and net-import values for the same quarter-hour, plus monthly and month-by-hour summaries. Derived from Energy-Charts (Fraunhofer ISE) data that originates from SMARD.de and the ENTSO-E Transparency Platform. Study, charts and method notes: https://atillabijenjalili.com/research/hungary-negative-quarter-hours-2025-2026/ Source credit: Contains data from Fraunhofer ISE Energy-Charts API, from Bundesnetzagentur | SMARD.de; Fraunhofer ISE Energy-Charts API, from the ENTSO-E Transparency Platform. Files: hu-negative-quarter-hours-2025-26-monthly.csv: Monthly summary (12 rows) hu-negative-quarter-hours-2025-26-month-hour.csv: Month by hour (288 rows) hu-negative-quarter-hours-2025-26-list.csv: Every negative quarter-hour (894 rows) README.md describes every column and its unit.