Lead organisation

To lead a collaborative project or to work alone, your organisation must be a UK registered business of any size.

More information on the different types of organisation can be found in our Funding rules.

Academic institutions cannot lead or work alone.

Project team

To collaborate with the lead, your organisation must be one of the following UK registered:

• business of any size
• academic institution
• charity
• not for profit
• public sector organisation
• research and technology organisation (RTO)

If your project is collaborative, you must ensure no single organisation claims more than 70% of the total project costs.

Number of applications

An eligible organisation can only lead on one application.

An eligible organisation that is leading an application can be included as a collaborator in a further two applications. An eligible organisation that is not leading an application can collaborate in any number of applications.

We welcome and encourage applications from people of all backgrounds and are committed to making our application process accessible to everyone. This includes making reasonable adjustments for people who have a disability or a long-term condition and face barriers applying to us.

You can contact us at any time to ask for guidance.

We recommend you contact us at least 15 working days before this competition’s closing date to allow us to put the most suitable support in place. The support we can provide may be limited if you contact us close to the competition deadline.

You can contact Innovate UK by email or call 0300 321 4357. Our phone lines are open from 9am to 12pm and 2pm to 5pm UK time, Monday to Friday (excluding bank holidays).

Your project must:

• have a grant funding request of between £350,000 and £700,000
• last between 3 and 9 months
• start by 1 January 2027
• end by 30 September 2027

Any organisation receiving funding must carry out its project work in the UK, intend to exploit the results in the UK, and spend most of the funding within the UK.

This Phase 1 competition is providing funding for project development studies (formally classified as feasibility studies) to strengthen demonstration project proposals under the planned future Phase 2 competition. A first draft of your project development study must be completed by 31 May 2027. This is to ensure that your project is able to inform your application to a Phase 2 competition.

Your project under Phase 1 must show a clear route to construction and operation in the UK, with a specific site identified as part of the project development study. Your selected site may be located at a demonstration or test facility that you have an arrangement with, a facility you already own, or within a greenfield development. Your choice of proposed site will be considered in the context of the maturity and scale of your technology.

You must demonstrate a credible route to deployment, including how you will secure any outstanding permits, consents, infrastructure and site arrangements within the project timescales. Any site preparation and development risks must be clearly outlined. Project sponsors must prioritise sites that minimise such risks.

Your project development study must contain, as a minimum:

• technology assessment
• engineering design
• cost and scale-up roadmap
• market assessment
• development plan
• manufacturing and supply chain plan

Changes from the previous scope are shown in bold below.

The aim of this competition is to support the development, scale-up, and UK manufacture of electrochemical ultra long duration energy storage (ULDES) technologies. These ULDES technologies must be capable of delivering cost effective electrical power to the UK’s electricity grid with a discharge availability of at least 100 continuous hours at rated power, regardless of the time required to charge the system. They must also achieve a working life of at least 25 years.

Your project must:

• involve the proposed deployment of electrochemical ULDES technologies which have a round trip power to power cycle, where electricity is used to charge the system and electricity is produced on discharge
• fulfil the requirements under one of the two streams outlined in this section
• support a planned UK demonstration project by 2030, meeting the scale and timetable requirements of your selected stream, as part of a pathway to scalable deployment in the UK energy system
• demonstrate that the proposed lead or team has the capabilities required to progress from project development studies through to demonstration and deployment

A technology neutral approach has been adopted within defined boundaries.

These have changed since the original publication: please consult the revised competition page to ensure you have the correct details. Sections which have changed are shown in bold.

Stream 1: near commercial scale-up

Stream 1 aims to develop and demonstrate near commercial electrochemical ULDES systems that have the potential to achieve installed system costs of $40/kWh or less, by 2030.

Your project must:

• feature an electrochemical ULDES technology able to store energy for several days and provide intraday and interday energy arbitrage, uninterruptible power supply (UPS) and backup power for long outages including commercial and industrial applications and critical infrastructure
• plan to deliver a grid connected demonstration project of at least 1 MW and 100 MWh (rated to discharge) by 2030
• envisage achieving a total installed cost of US$40/kWh, or less, by 2030
• provide a commercialisation plan showing how the technology will scale in the UK energy system
• demonstrate your ambition for developing UK manufacturing capacity and building domestic supply chains

Stream 2: system innovation and low cost pathways

Stream 2 aims to develop early stage electrochemical ULDES technologies that have the potential to achieve installed system costs of US$15/kWh or less, by 2035.

Your project must:

• feature an electrochemical ULDES technology that can provide monthly and seasonal energy arbitrage, equivalent to a UK strategic reserve, demonstrating the potential for minimal degradation or self discharge over long periods
• plan to deliver a grid connected pilot demonstration project of at least 1kW and 100 kWh (rated to discharge) by 2030
• envisage achieving a total installed cost of $15/kWh, or less, by 2035
• provide a commercialisation plan showing how the technology will scale in the UK energy system
• demonstrate your ambition for developing UK manufacturing capacity and building domestic supply chains

System costs calculation

(this section was not included in the original competition brief)

Installed system costs include the total system CAPEX required to deliver a storage system with a 25 year system lifetime, including the capital cost of any component replacement required during that period, but excluding grid connection costs. Installed system costs are different from total cost of ownership (TCO) and levelised cost of storage (LCOS). You do not need to provide LCOS or net present value (NPV) calculations as part of your application.

If you choose to include LCOS and NVP calculations, you must clearly state your assumptions, including:

• cycles per year
• charging electricity price
• discount rate
• system lifetime
• efficiency
• degradation

The core storage cost assessment must exclude additional revenue streams. You can provide information on potential additional revenue streams separately.

Changes to the previous list of exclusions are shown in bold below.

We are not funding projects that are:

• focused on laboratory scale or early stage discovery research
• limited to component, material or subsystem development, or manufacturing process optimisation
• focused on incremental improvements to existing short duration battery energy storage technologies
• focused on the development or deployment of lithium ion, hydrogen fuel cell or lead acid technologies
• focused on the combustion of hydrogen, or other molecules, to produce electricity
• focused on technologies that store energy in the form of thermal, mechanical or electrical energy, including molten salts, compressed air, pumped-hydro storage and capacitors

7 August 2026: Online briefing event: watch the recording here

27 August 2026: informal ‘drop-in’ surgery to ask any questions you may have about your application. Download the surgery Q&A.

2 November 2026: Applicants notified

1 January 2027: Project start by

An online briefing event was held on 7 August 2026 (recording link below) and a surgery on 27 August at 13:30 (not recorded).

View the briefing event recording, slides and Q&A.

Download the surgery Q&A.

If you would like help to find a collaboration partner, contact Innovate UK Business Connect’s Energy team.