Novel solutions for off-grid storage of renewable energy for critical infrastructures

The grant opportunity HORIZON-CL5-2026-03-D3-21 focuses on developing innovative off-grid energy storage solutions for renewable energy, particularly for critical infrastructures such as hospitals and data centers. It is part of Horizon Europe's research and innovation actions and is classified as a HORIZON Lump Sum Grant. The funding total is €12 million, with an expected allocation of approximately €4 million per project for three grants. The application process uses a single-stage submission, with proposals due by March 31, 2026.

Eligible applicants include research institutions, universities, SMEs, and large enterprises capable of conducting research and innovation activities. The opportunity is open to participants from EU member states and associated countries, with specific encouragement for the inclusion of Ukrainian beneficiaries to support reconstruction efforts in Ukraine following recent conflicts.

The target sectors involve energy storage technologies, renewable energy solutions, and critical infrastructure resilience. The projects are expected to emphasize innovation and practical implementation, advancing scientific understanding while developing prototypes suitable for real-world applications.

Funding is structured as a non-reimbursable lump sum, which simplifies financial management for beneficiaries. There are no explicit co-funding requirements mentioned, although applicants should verify this in detailed project documentation. The projects should address challenges associated with renewable energy storage, such as managing variability and ensuring robustness under demanding conditions.

The application will undergo evaluation by independent experts post-submission. Although specific success rates are not provided, previous similar opportunities suggest moderate-to-high competitiveness. Applicants are encouraged to utilize partner search tools and available resources for support in forming strong consortia and developing their proposals effectively. This call is aligned with EU goals for climate neutrality and energy independence, contributing to Europe’s leadership in clean energy technologies.

This is a Horizon Europe call, specifically HORIZON-CL5-2026-03-D3-21, focusing on "Novel solutions for off-grid storage of renewable energy for critical infrastructures." It falls under the BATTERIES and ENERGY (HORIZON-CL5-2026-03) call within the Horizon Europe (HORIZON) program. It is a HORIZON Research and Innovation Action (HORIZON-RIA) with a HORIZON Lump Sum Grant [HORIZON-AG-LS] type of Model Grant Agreement (MGA). The deadline model is single-stage, with a planned opening date of December 18, 2025, and a deadline of March 31, 2026, at 17:00:00 Brussels time.

The expected outcomes of the projects funded under this topic include: Enhanced European knowledge and leadership in off-grid clean energy storage technologies, improved energy security and cost-effectiveness of Europe's energy systems (particularly for critical infrastructure), and the elimination of fossil-based backup solutions for critical infrastructures, thereby strengthening European competitiveness.

The scope of the topic is to develop novel, cost-efficient off-grid energy storage solutions for renewable energy, tailored for critical infrastructures such as hospitals, transport hubs, data centres, and utilities. The solutions should address challenges specific to off-grid or non-interconnected area contexts, including storage scale, compromised grid interaction, resilience to potential shortages of critical materials, and multi-energy needs (electricity, heating, cooling). Emphasis should be on robustness and error-freeness, while considering sustainability, efficiency and performance. The projects should foresee these solutions for using real-world critical infrastructures through simulation and experiments and establishing a procedure for decision-making, focusing on energy security and resilience against high-impact, low-probability events, by ensuring operational efficiency both on-grid and off-grid. Where relevant, interdependencies among critical infrastructures and system redundancy should be considered. Projects are encouraged to support the reconstruction of Ukraine by including Ukrainian beneficiaries.

The general conditions include:

1. Admissibility Conditions:
 - Proposal page limit and layout are described in Annex A and Annex E of the Horizon Europe Work Programme General Annexes.
 - Proposal page limits and layout are described in Part B of the Application Form available in the Submission System.

2. Eligible Countries:
 - Described in Annex B of the Work Programme General Annexes.
 - A number of non-EU/non-Associated Countries that are not automatically eligible for funding have made specific provisions for making funding available for their participants in Horizon Europe projects. See the information in the Horizon Europe Programme Guide.

3. Other Eligible Conditions:
 - If projects use satellite-based earth observation, positioning, navigation and/or related timing data and services, beneficiaries must make use of Copernicus and/or Galileo/EGNOS (other data and services may additionally be used).
 - Subject to restrictions for the protection of European communication networks.
 - Described in Annex B of the Work Programme General Annexes.

4. Financial and operational capacity and exclusion:
 - Described in Annex C of the Work Programme General Annexes.

5a. Evaluation and award: Award criteria, scoring and thresholds:
 - Are described in Annex D of the Work Programme General Annexes.

5b. Evaluation and award: Submission and evaluation processes:
 - Are described in Annex F of the Work Programme General Annexes and the Online Manual.

5c. Evaluation and award: Indicative timeline for evaluation and grant agreement:
 - Described in Annex F of the Work Programme General Annexes.

6. Legal and financial set-up of the grants:
 - The granting authority may, up to 4 years after the end of the action, object to a transfer of ownership or to the exclusive licensing of results, as set out in the specific provision of Annex 5.
 - Eligible costs will take the form of a lump sum as defined in the Decision of 7 July 2021 authorising the use of lump sum contributions under the Horizon Europe Programme – the Framework Programme for Research and Innovation (2021-2027) – and in actions under the Research and Training Programme of the European Atomic Energy Community (2021-2025). This decision is available on the Funding and Tenders Portal, in the reference documents section for Horizon Europe, under ‘Simplified costs decisions’ or through this link: https://ec.europa.eu/info/funding-tenders/opportunities/docs/2021-2027/horizon/guidance/ls-decision_he_en.pdf.
 - Described in Annex G of the Work Programme General Annexes.

Specific conditions are described in the specific topic of the Work Programme.

The application and evaluation forms and model grant agreement (MGA) include:
 - Application form templates: The application form specific to this call is available in the Submission System.
 - Standard application form (HE RIA, IA)
 - Evaluation form templates: Will be used with the necessary adaptations.
 - Standard evaluation form (HE RIA, IA)
 - Guidance: HE Programme Guide
 - Model Grant Agreements (MGA): Lump Sum MGA
 - Call-specific instructions: Detailed budget table (HE LS), Guidance: "Lump sums - what do I need to know?"

Additional documents include:
 - HE Main Work Programme 2026-2027 – 1. General Introduction
 - HE Main Work Programme 2026-2027 – 8. Climate, Energy and Mobility
 - HE Main Work Programme 2026-2027 – 15. General Annexes
 - HE Programme Guide
 - HE Framework Programme 2021/695
 - HE Specific Programme Decision 2021/764
 - EU Financial Regulation 2024/2509
 - Decision authorising the use of lump sum contributions under the Horizon Europe Programme
 - Rules for Legal Entity Validation, LEAR Appointment and Financial Capacity Assessment
 - EU Grants AGA — Annotated Model Grant Agreement
 - Funding & Tenders Portal Online Manual
 - Funding & Tenders Portal Terms and Conditions
 - Funding & Tenders Portal Privacy Statement

The budget overview for the call in 2026 is as follows:
 - HORIZON-CL5-2026-03-D2-02 - HORIZON-RIA: EUR 14,200,000, Single-stage, Indicative number of grants: 3, Contributions around EUR 4,700,000
 - HORIZON-CL5-2026-03-D3-01 - HORIZON-RIA: EUR 9,000,000, Single-stage, Indicative number of grants: 3, Contributions around EUR 3,000,000
 - HORIZON-CL5-2026-03-D3-12 - HORIZON-RIA: EUR 15,000,000, Single-stage, Indicative number of grants: 3, Contributions around EUR 5,000,000
 - HORIZON-CL5-2026-03-D3-13 - HORIZON-IA: EUR 31,500,000, Single-stage, Indicative number of grants: 3, Contributions around EUR 10,500,000
 - HORIZON-CL5-2026-03-D3-18 - HORIZON-IA: EUR 20,000,000, Single-stage, Indicative number of grants: 2, Contributions around EUR 10,000,000
 - HORIZON-CL5-2026-03-D3-19 - HORIZON-IA: EUR 24,000,000, Single-stage, Indicative number of grants: 3, Contributions EUR 4,000,000 to EUR 12,000,000
 - HORIZON-CL5-2026-03-D3-20 - HORIZON-IA: EUR 14,000,000, Single-stage, Indicative number of grants: 2, Contributions around EUR 7,000,000
 - HORIZON-CL5-2026-03-D3-21 - HORIZON-RIA: EUR 12,000,000, Single-stage, Indicative number of grants: 3, Contributions around EUR 4,000,000
 - HORIZON-CL5-2026-03-D3-22 - HORIZON-IA: EUR 12,000,000, Single-stage, Indicative number of grants: 2, Contributions around EUR 6,000,000
 - HORIZON-CL5-2026-03-D3-29 - HORIZON-IA: EUR 25,000,000, Single-stage, Indicative number of grants: 5, Contributions around EUR 5,000,000

There are partner search announcements available for those looking to collaborate on this topic. LEARs, Account Administrators, or self-registrants can publish partner requests after logging into the portal. The submission system is planned to open on the date stated on the topic header.

For support, applicants are encouraged to read all provisions carefully before preparing their application. The Online Manual serves as a guide for procedures from proposal submission to grant management. The Horizon Europe Programme Guide contains detailed guidance on the structure, budget, and political priorities of Horizon Europe. The Funding & Tenders Portal FAQ provides answers to frequently asked questions on proposal submission, evaluation, and grant management. The Research Enquiry Service can answer questions about European research and the EU Research Framework Programmes. National Contact Points (NCPs) offer guidance and practical information, and the Enterprise Europe Network (EEN) provides advice to businesses, especially SMEs. The IT Helpdesk addresses technical questions related to the Funding & Tenders Portal. The European IPR Helpdesk assists with intellectual property issues, and CEN-CENELEC/ETSI Research Helpdesks advise on standardisation in project proposals. The European Charter for Researchers and the Code of Conduct for their recruitment outline the roles and responsibilities of researchers, employers, and funders. Partner Search tools are available to help find partner organisations for proposals.

In summary, this Horizon Europe call seeks innovative and cost-effective off-grid energy storage solutions for renewable energy sources, specifically designed for critical infrastructures. The projects should aim to enhance European leadership in clean energy storage, improve energy security, and eliminate reliance on fossil fuels. The call encourages collaboration with Ukrainian beneficiaries and provides a lump sum grant. Applicants should carefully review the general and specific conditions, utilize the available support resources, and consider partner search options to develop strong and impactful proposals. The call aims to address the unique challenges of off-grid energy storage, such as scale, grid interaction, material scarcity, and multi-energy needs, while emphasizing robustness, sustainability, and operational efficiency.

Eligible Applicant Types: The eligible applicant types are not explicitly stated, but based on the nature of Horizon Europe Research and Innovation Actions (RIA) and Innovation Actions (IA), eligible applicants can include universities, research institutes, SMEs, large enterprises, and other organizations capable of conducting research and innovation activities. The program encourages the inclusion of Ukrainian beneficiaries.

Funding Type: The funding type is primarily a grant, specifically a HORIZON Lump Sum Grant. There are both Research and Innovation Actions (RIA) and Innovation Actions (IA) available.

Consortium Requirement: The opportunity does not explicitly state whether a single applicant or a consortium is required. However, given the scope and nature of the projects, a consortium is highly probable. Partner search announcements are available, suggesting that collaboration is encouraged.

Beneficiary Scope (Geographic Eligibility): The geographic eligibility includes EU member states, associated countries, and potentially non-EU/non-associated countries with specific provisions as detailed in Annex B of the Work Programme General Annexes and the Horizon Europe Programme Guide.

Target Sector: The target sector is energy, specifically renewable energy and energy storage solutions. It also touches upon critical infrastructure, climate, and mobility.

Mentioned Countries: Ukraine is explicitly mentioned as projects are encouraged to support its reconstruction by including Ukrainian beneficiaries. The opportunity is open to EU member states and associated countries, and potentially non-EU/non-associated countries.

Project Stage: The project stage varies depending on the type of action. Research and Innovation Actions (RIA) typically support activities from research to validation, while Innovation Actions (IA) focus on demonstration and deployment. Therefore, the project stage can range from research and development to demonstration and validation.

Funding Amount: The funding amounts vary depending on the specific topic within the call. The budget overview provides the following ranges:
HORIZON-CL5-2026-03-D2-02: EUR 14,200,000 (around EUR 4,700,000 per grant, 3 grants)
HORIZON-CL5-2026-03-D3-01: EUR 9,000,000 (around EUR 3,000,000 per grant, 3 grants)
HORIZON-CL5-2026-03-D3-12: EUR 15,000,000 (around EUR 5,000,000 per grant, 3 grants)
HORIZON-CL5-2026-03-D3-13: EUR 31,500,000 (around EUR 10,500,000 per grant, 3 grants)
HORIZON-CL5-2026-03-D3-18: EUR 20,000,000 (around EUR 10,000,000 per grant, 2 grants)
HORIZON-CL5-2026-03-D3-19: EUR 24,000,000 (EUR 4,000,000 to EUR 12,000,000 per grant, 3 grants)
HORIZON-CL5-2026-03-D3-20: EUR 14,000,000 (around EUR 7,000,000 per grant, 2 grants)
HORIZON-CL5-2026-03-D3-21: EUR 12,000,000 (around EUR 4,000,000 per grant, 3 grants)
HORIZON-CL5-2026-03-D3-22: EUR 12,000,000 (around EUR 6,000,000 per grant, 2 grants)
HORIZON-CL5-2026-03-D3-29: EUR 25,000,000 (around EUR 5,000,000 per grant, 5 grants)

Application Type: The application type is an open call with a single-stage submission process.

Nature of Support: The beneficiaries will receive money in the form of a lump sum grant.

Application Stages: The application process involves a single stage.

Success Rates: The success rates are not explicitly stated, but the indicative number of grants for each topic provides some insight. For example, HORIZON-CL5-2026-03-D3-29 aims to award around 5 grants from a budget of EUR 25,000,000.

Co-funding Requirement: The need for co-funding is not explicitly mentioned. However, Horizon Europe grants often fund a percentage of the total eligible costs, implying that applicants may need to secure additional funding from other sources.

Summary: This Horizon Europe call, under the BATTERIES and ENERGY theme (HORIZON-CL5-2026-03), aims to foster research and innovation in novel, cost-efficient off-grid energy storage solutions for renewable energy sources. The call is structured around several topics, each with a specific budget and scope, targeting different aspects of energy storage and grid interaction. The projects should focus on critical infrastructures like hospitals, transport hubs, data centers, and utilities, addressing challenges related to storage scale, grid interaction, material resilience, and multi-energy needs. The call encourages the inclusion of Ukrainian beneficiaries to support the reconstruction of Ukraine. The funding is provided as a lump sum grant, and the application process is a single-stage submission. Applicants should consult the Horizon Europe Programme Guide and other relevant documents for detailed guidance on eligibility, evaluation criteria, and submission procedures. Partner search opportunities are available to facilitate the formation of strong consortia. The call aims to enhance European knowledge and leadership in off-grid clean energy storage technologies, improve energy security and cost-effectiveness, and eliminate fossil-based backup solutions, thereby strengthening European competitiveness.