What AquaBattery does

AquaBattery is a Netherlands-based climate technology startup founded in 2014 that develops saltwater-based flow battery systems for long-duration energy storage (LDES). Its core product is an acid-base flow battery using saltwater as the electrolyte, capable of storing renewable energy for 8 to 100 hours, an operating window that targets multi-day bridging between renewable generation peaks and demand troughs, and that conventional lithium-ion or short-duration batteries cannot efficiently serve. The technology is positioned as non-flammable, non-toxic, and free of scarce or hazardous materials, addressing grid-scale energy storage needs without the safety or supply-chain constraints of incumbent chemistries.

The company pursues a B2B enterprise and utility-focused business model, targeting grid operators, renewable energy producers, industrial facilities, ports, and horticulture operators. Commercial deployment is pre-revenue, with revenue expected to be generated through hardware sales of grid-scale storage systems and potentially managed services for energy storage capacity and grid balancing. Pricing is quote-based and not publicly disclosed. AquaBattery operates a direct enterprise field-sales motion and has begun commercial validation through pilot deployments in Delft, the Port of Rotterdam, De Kwakel, and Altena, primarily via the RenewaFLEXNL consortium coordinated by TNO.

The company is privately held and venture-backed, having raised approximately $8.96 million in cumulative disclosed funding through a December 2021 European Innovation Council grant and an April 2024 €6 million seed round led by EIT InnoEnergy with participation from InnovationQuarter, Invest-NL, and Bob Sponge. Its go-to-market relies heavily on industry consortium participation, strategic partnerships (notably the Letter of Intent with Sciven), and earned media rather than traditional marketing channels. The global long-duration energy storage market is reported at USD 3.14 billion in 2024 and projected to reach USD 4.44 billion by 2032, providing the addressable market backdrop for AquaBattery's commercialization trajectory.

Name

AquaBattery

Legal name

AquaBattery

Website

https://aquabattery.nl

Company type

Private

Founded year

2014

Operating status

Operating

Headcount range

11–50 employees

Short description

AquaBattery is a Dutch climate tech startup developing saltwater-based flow battery systems for long-duration energy storage (8-100 hours), targeting utilities, grid operators, ports, and industrial facilities across the European market.

Ownership category

akta.pro rank

Product category

Long-Duration Energy Storage

NAICS

Battery Manufacturing (335910), Battery Manufacturing (33591)

akta.pro primary industry

Electrochemical LDES (Flow Batteries & Other Long-Duration Batteries) (EUAFADAA)

Keywords

• Long-duration energy storage
• Saltwater flow battery
• Grid-scale battery systems
• Renewable energy storage
• Acid-base flow battery

Headquarters

HQ city

Leiderdorp

HQ country

Netherlands

HQ region

Europe

Offices1 record

Markets served

GTM type

B2B

Offering type

Hardware or Manufacturing

Cost components

Technology or R&D, Operations, Personnel, Supply Chain, Marketing or Sales

Revenue model

1. Grid-Scale Energy Storage Systems: Sale and deployment of large-scale saltwater flow battery systems to utilities, grid operators, and industrial customers for long-duration energy storage applications. Revenue likely generated through system sales, installation, and potentially ongoing maintenance contracts.
2. Energy Storage Services: Providing energy storage capacity and grid services to address grid congestion, renewable integration, and energy arbitrage opportunities in the European energy market.

Go-to-market motion1 record

Distribution channels1 record

Marketing channels3 records

Core offering

AquaBattery develops and manufactures saltwater-based flow battery systems designed for long-duration energy storage (LDES) of 8 to 100 hours. The acid-base flow battery technology uses saltwater as the electrolyte to provide a non-flammable, non-toxic alternative to conventional battery chemistries, targeting grid operators, utilities, and industrial customers seeking to integrate renewable energy and reduce grid congestion.

Product overview

AquaBattery offers a single core technology: its saltwater flow battery for long-duration energy storage. This acid-base flow battery technology stores renewable energy for extended periods (8-100 hours) and is designed for applications including offshore wind integration, greenhouse energy solutions, and regional energy systems. The company is scaling this technology through pilot projects in the Netherlands, supported by its €6 million seed funding round.

Differentiator

Problem solved

Functional benefit

Products and services

• Saltwater Flow Battery A long-duration energy storage technology using saltwater as the electrolyte, based on acid-base flow battery principles. Designed to store renewable energy for 8 to 100 hours for utilities, grid operators, and industrial facilities addressing grid congestion and renewable integration challenges.
• Long Duration Energy Storage (LDES) Solutions

Segments3 records

Ideal customer profiles3 records

Technology focussed Yes

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature3 records

Partnerships

Five partnerships are on record, tiered core, flagship and minor.

• TNO (Netherlands Organization for Applied Scientific Research)coreStrategic or Co-development Partner · 17 February 2026TNO coordinates the three-year RenewaFLEXNL project in which AquaBattery's saltwater flow battery is being deployed in three pilot locations (Rotterdam Port, De Kwakel, Altena). TNO provides research infrastructure and coordinates 17 partners across the Dutch energy value chain.
• RenewaFLEXNL Consortium (17 partners)coreStrategic or Co-development Partner · 17 February 2026A consortium of 17 partners coordinated by TNO for the three-year RenewaFLEXNL project to integrate long-term energy storage into the Dutch energy system. Technologies tested include AquaBattery's saltwater flow battery alongside ORE Energy's iron-air system and BB1 Project's thermal-electric hybrid storage.
• ScivenflagshipStrategic or Co-development Partner · 30 October 2025Aquabattery and Sciven signed a Letter of Intent to collaborate on long-duration energy storage solutions through joint pilot projects and technical validation. The partnership aims to accelerate commercialization of AquaBattery's LDES technology and explore deployment opportunities in target markets.
• ORE EnergyminorStrategic or Co-development PartnerFellow storage technology provider in the RenewaFLEXNL consortium testing iron-air (reversible iron oxidation) multi-day storage technology alongside AquaBattery's flow battery solution.
• BB1 ProjectminorStrategic or Co-development PartnerFellow storage technology provider in the RenewaFLEXNL consortium testing hybrid thermal-electric storage combining heat pumps, water-based thermal storage, and sodium-ion batteries alongside AquaBattery's solution.

Scale indicators5 records

Recent moves6 records

Expansion highlights5 records

Direct peers

• ESS Inc. US-based flow battery company commercializing iron-saltwater flow batteries for long-duration grid storage. Most direct peer to AquaBattery given the flow battery architecture and grid-scale LDES focus.
• Invinity Energy Systems: UK-based vanadium redox flow battery manufacturer targeting commercial and utility-scale long-duration storage. Direct peer in flow battery category for grid applications.
• ORE Energy: Dutch iron-air LDES developer participating in the same RenewaFLEXNL consortium as AquaBattery. Direct peer competing head-to-head for Dutch pilots and utility validation.
• CellCube (Enerox): Austria-based vanadium redox flow battery company commercializing large-scale stationary storage. Direct peer in flow battery technology for long-duration grid applications.

Broad incumbents

• Form Energy: US-based LDES leader developing iron-air batteries targeting 100+ hour discharge. Broad incumbent in the same long-duration storage market AquaBattery addresses, with significantly more capital.
• Energy Vault: Public company developing gravity-based mechanical LDES plus battery energy storage solutions. Competes for the same utility-scale long-duration procurement budgets in Europe.
• Highview Power: UK-based liquid air energy storage (LAES) developer for multi-day grid storage. Targets the same long-duration niche as AquaBattery with an alternative non-lithium approach.
• Sumitomo Electric: Large Japanese industrial conglomerate with a commercialized redox flow battery business for grid-scale storage. Broad incumbent with established deployments competing in the same addressable market.
• Lockheed Martin (GridStar Flow): US defense contractor that developed an iron redox flow battery (GridStar Flow) for grid storage. Broad incumbent with adjacent flow battery technology targeting utility customers.

Emerging players

• StorEn Technologies: US/Australian vanadium flow battery developer for residential, commercial, and grid-scale markets. Emerging flow battery peer with overlapping LDES use cases.

Market position

Strengths4 records

Weaknesses4 records

Competitive moat4 records

Key risks5 records

Key highlights6 records

Customer concentration

Revenue estimate

Valuation estimate

Number of profiles

Profiles1 record

Funding overview

Funding rounds2 records

Investors5 records

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about AquaBattery