HORTA

Introduction

The rapid growth of renewable energy sources such as wind and solar is essential for achieving climate neutrality, but their intermittent nature creates significant challenges for grid stability and industrial energy supply. To enable large-scale integration of these renewables, long-duration energy storage (LDES) solutions will be needed in the next decade. Current technologies often rely on scarce materials or involve high costs, limiting their scalability. Organic redox flow batteries (ORFBs) offer a promising alternative: they are safe, sustainable, and modular, and their active materials can be sourced and produced locally. This strengthens energy resilience in Flanders and the EU while reducing dependency on critical raw materials. Addressing this challenge is crucial for energy-intensive sectors such as chemicals, steel, and glass.

Goal

The HORTA project aims to develop a high-performing non-aqueous organic redox flow battery (NAORFB) technology that can serve as a competitive LDES solution for industrial and grid-connected applications. The project targets a technology readiness level (TRL) of 4 by delivering validated components and an integrated lab-scale prototype. Rather than focusing on incremental improvements, HORTA seeks to establish a robust platform for future industrial demonstrations. By combining material innovation, system integration, and sustainability assessments, the project will provide a clear pathway toward commercialization and large-scale deployment within the next decade.

Approach

HORTA adopts a multidisciplinary approach that combines advanced molecular design, material engineering, and system-level optimization. Novel organic electrolytes will be developed to achieve high energy density and long-term stability, supported by computational modeling while focusing on scalable and sustainable synthesis routes. Membranes and electrodes will be optimized for efficiency and durability, and integrated into an optimized lab-scale prototype to validate performance under realistic conditions. Beyond technical development, the project includes a comprehensive sustainability and techno-economic analysis to ensure industrial relevance. Collaboration with an Industrial Advisory Board and research partners guarantees alignment with market needs and accelerates technology transfer.

Expected impact and valorization

HORTA will deliver a breakthrough in cost-effective, modular LDES solutions, enabling Flemish industry to achieve deep decarbonization and meet Moonshot Path 4 targets. The technology has the potential to avoid significant CO₂ emissions by replacing fossil-based electricity with renewable energy storage. Its local production and CRM-free design enhance supply chain independence and competitiveness. Valorization will occur through multiple channels: bilateral R&D with industrial partners, IP licensing to manufacturers, and potential spin-off creation. The project’s strong IP position and industrial commitment confirm market appetite and readiness for adoption. With successful TRL 4 validation, integration into industrial energy systems is expected within 5–10 years, supported by follow-up demonstration projects and policy uptake.

Members of the HORTA consortium during the project kick-off meeting on 2 April 2026.