Next generation flexible trigeneration geothermal ORC plant

Projektinformationen

nGEL

ID Finanzhilfevereinbarung: 101148170

DOI

10.3030/101148170

EK-Unterschriftsdatum 23 April 2024

Startdatum 1 Juni 2024

Enddatum 31 Mai 2028

Finanziert unter

• Climate, Energy and Mobility

Gesamtkosten

€ 5 214 465,00

EU-Beitrag

€ 4 346 688,47

Koordiniert durch

FRAUNHOFER GESELLSCHAFT ZUR FORDERUNG DER ANGEWANDTEN FORSCHUNG EV
Germany

Periodic Reporting for period 1 - nGEL (Next generation flexible trigeneration geothermal ORC plant)

Berichtszeitraum: 2024-06-01 bis 2025-09-30

Zusammenfassung vom Kontext und den Gesamtzielen des Projekts

Europe’s transition toward climate neutrality requires flexible, low-carbon energy systems able to provide electricity, heating, and cooling in a reliable and cost-effective manner. Geothermal energy, widely available across Europe, offers a stable renewable heat source, yet most existing geothermal plants operate in inflexible baseload mode and cannot easily respond to market fluctuations or rising system-wide demands for flexibility.

nGEL aims to transform this situation by developing the next-generation flexible geothermal trigeneration system. The project integrates an Organic Rankine Cycle (ORC), high- and low-temperature thermal energy storage (HTES and CTES), an absorption chiller, and an advanced energy management system (EMS). Together, these technologies enable a geothermal plant to dynamically alternate between producing electricity, heat, and cooling depending on energy prices, grid needs, and local demand.

The project’s overarching objectives are to:
• Demonstrate a flexible ORC plant capable of responding to electricity market signals;
• Enhance operational reliability under high ambient temperatures;
• Develop novel CTES and HTES storage for efficiency and cost reduction;
• Implement AI-based forecasting, control and EMS for optimal multi-energy operation;
• Quantify environmental, economic and societal impacts through LCA, techno-economics, and public engagement;
• Validate the complete system at an industrial-scale geothermal site in Türkiye.

By enabling trigeneration, improved flexibility, and storage-supported operation, nGEL contributes to EU strategies for renewable integration, reduced fossil fuel dependency, and a more resilient energy system.

Arbeit, die ab Beginn des Projekts bis zum Ende des durch den Bericht erfassten Berichtszeitraums geleistet wurde, und die wichtigsten bis dahin erzielten Ergebnisse

During RP1 (M1–M16), the consortium established the full technical, organisational and scientific foundations of the nGEL system.

WP1 defined the operational requirements, system boundaries and functional specifications for the trigeneration concept. A detailed Process Flow Diagram (PFD), operational scenario matrix, safety assessment and preliminary control-logic structure were completed.

WP2 performed extensive laboratory research on CTES materials (87 PCMs screened, 4 shortlisted). Thermal characterisation, corrosion testing and long-term cycling were initiated, and detailed Modelica models for CTES and HTES were developed. The HTES concept was refined with new PCM options following market changes.

WP3 prepared the advanced control and EMS framework. A comprehensive forecasting dataset (electricity prices, weather, operational data) was created, and the control scope for flexible ORC and DSM was defined. Work on virtual DH network modelling and DSM/FDD logic was initiated.

WP4 completed the engineering design of the demonstration system. The small ORC module (64 kW gross) was fully designed, key components procured, and site integration plans, tie-in lists and safety documents prepared.

WP5 developed AI-based ORC output prediction models (LSTM showing best accuracy) and produced the first design of the nGEL digital twin/DSS. The social awareness campaign reached >100 participants across workshops and webinars.

WP6–7 ensured effective communication, dissemination, exploitation planning, governance, reporting and financial/administrative management.

Overall, RP1 achieved all core milestones and established strong technical progress across all WPs.

Fortschritte, die über den aktuellen Stand der Technik hinausgehen und voraussichtliche potenzielle Auswirkungen (einschließlich der bis dato erzielten sozioökonomischen Auswirkungen und weiter gefassten gesellschaftlichen Auswirkungen des Projekts)

nGEL advances geothermal trigeneration substantially beyond current industry practice.
Existing low-enthalpy geothermal ORC plants typically operate at fixed baseload conditions, with limited ability to modulate operation or shift between heating, cooling and electricity generation.

The project introduces several innovations:
• Flexible ORC operation combining ACC load-sharing, smart control, and storage-supported operation while enabling responsiveness to market signals previously not achievable.
• New CTES system designs, using refined PCM selection, corrosion-resistant materials and advanced finned-tube geometries simulated via high-fidelity Modelica models. This provides improved charge/discharge behaviour and long-term cycling capability.
• AI-driven forecasting for multi-energy operation, with high-accuracy AI-based ORC output prediction and a dedicated dataset for energy price forecasting—significantly improving planning and scheduling.
• Development of an integrated Energy Management System (EMS) capable of coordinating tri-generation assets and evaluating economic, environmental and operational trade-offs.
• Introduction of a digital twin and decision-support system (DSS) that merges thermodynamic modelling, techno-economics and LCA to support operation, planning and investment decisions.

These advances enable a new class of smart, flexible and efficient geothermal plants, positioning geothermal energy as a competitive player in future hybrid renewable energy systems.