AquaStroke®

Clean backup power, anytime, anywhere!

RDM Demo

The fossil-free generator

for a new standard in emergency power

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AquaStroke® is an innovative method of power generation, designed for a future without fossil fuels. This patented engine technology runs on a unique fuel blend of 70% water and 30% bio-alcohol. AquaStroke® delivers quiet, clean, and powerful energy, with significantly lower emissions than conventional generators.

Clean backup power, exactly when needed
The AquaStroke 35 kW is a fossil-free standby (backup) generator under SCIOS classification (≤500 hours/year), designed to provide reliable backup during outages or scheduled maintenance.

In partnership with technology partner MayMaan Research Inc., and as part of Vattenfall, Feenstra is introducing this innovation to the European market.

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Aquastroke Assembly vid

What Makes Aquastroke Unique?

✅ 100% Fossil-Free – runs on a renewable water and bio-alcohol  blend
✅ Exceptionally Low Emissions – no black smoke, no diesel odor
✅ Low Noise – suitable for use in residential areas
✅ Emergency power / standby — SCIOS classified
✅ Flexible Deployment – off-grid, mobile, modular, and scalable

Technical advantages

🚰 Patented Water and Bio-alcohol Fuel System
Enables clean, efficient combustion with greatly reduced harmful emissions.

⚡ High Compression Ratio
Delivers more power and torque with lower fuel consumption.

🌿 No After-Treatment Required
No particulate filters, AdBlue, or regeneration cycles needed.

🔧 Reduced Maintenance
Less carbon buildup, cleaner oil, and extended maintenance intervals.

🔌 Modular & Scalable
Operates independently or in hybrid energy applications.

Note: Performance and emissions are based on manufacturer data; independent EU validation and CE documentation will follow / are available for inspection.

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"The Fossil-Free Generator for a New Standard in Emergency and Mobile Power Supply"

A New Generation of Generators

The AquaStroke® generators are suited to situations without grid access or where sustainability is a priority:

For 35 kW (now available as pilot):
🔹 Emergency / stand-by for critical loads (IT, telecom, pumps).
🔹 Short-duration back-up during outages or maintenance.
🔹 Temporary use (≤500 hours/year, SCIOS).

For 120 kW & AquaVolt (in development):
🔹 Intended for heavier / continuous applications.
🔹 Hybrid charging solutions / DC fast charging (AquaVolt).
🔹 Projects with higher power demand.

The first models are being prepared and will be tested at pilot locations in the Netherlands from early 2026..

Check out our generators
aquastroke 35 + aquavolt
video

Cutting-Edge Technology – Proven in Practice

The AquaStroke® technology was developed in the United States, where it is already being deployed in pilot projects. In Europe, it is in the final stages of validation and certification. A CE Declaration of Conformity is now available for the 35 kW emergency/stand-by version. Additional documentation and assessment for broader market application are in preparation.

According to internal tests conducted in the U.S., MayMaan reports low emission values, with minimal soot formation and combustion temperatures below the NOx threshold of 900 °C. These results are currently being independently validated in accordance with European emission standards and requirements.

Watch the video – see the Aquastroke technology in action.

Responsible and Realistic Communication

AquaStroke® is designed to contribute to the energy transition. Claims regarding CO₂ reduction, emission performance, and cost savings are based on preliminary test results and early field experiences. Independent validation and supporting documentation are underway. We are committed to transparency and welcome you to follow the continued development of this innovative technology.

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Aquastroke 120 - 3

availability

🔵 AquaStroke 35 kW – emergency/stand-by – pilot introduction Q1 2026

🔵 AquaStroke 120 kW – powerful industrial generator (2026)

🔵 AquaVolt Max – 120 kW generator with integrated DC fast charger (2026)

Want to be the first to receive updates on progress, availability, or to attend a demonstration? Leave your details using the form below.

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The generators

AquaStroke® generators are being developed for a wide range of applications and power ratings. Discover which model best fits your needs.
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AquaStroke 35

Automatic emergency (back-up) 35 kW generator (SCIOS, ≤500 hours/year)
35KW 230V / 400V - 50Hz
Equipped with a 2.3 L turbo engine
Manufacturer: Ford
Model: Duratec 4-cylinder

View this model
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aquastroke 120

Automatic Standby and Primary Power 120kW Generator
120 kW | 230V / 400V - 50 Hz
Powerful 6.2 L Naturally Aspirated Engine
Manufacturer: GM
Model: LT1GenV 6.2L

View this model
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AquaVolt Max

Automatic Standby and DC fast-charger up to 250 kW
120 kW | 230V / 400V - 50Hz
6.2 L engine + DC fast-charge
Manufacturer: GM
Model: LT1GenV 6.2L

View this model

ABOUT US

AquaStroke® Europe is an initiative of Feenstra, part of Vattenfall, in collaboration with the U.S. technology developer MayMaan Research Inc. Together, we aim to deliver practical, scalable, and sustainable solutions for today’s—and tomorrow’s—energy challenges.

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Frequently Asked Questions

The AquaStroke® generator is an innovative power solution that runs on a unique blend of 30% bio-alcohol and 70% water. This fossil-free fuel delivers clean, reliable energy with low emissions – without relying on fossil fuels like diesel or gasoline.

AquaStroke® has been developed as an alternative to conventional fossil fuel systems, aiming to enable cleaner energy generation and potential CO₂ reduction. We communicate transparently about this: claims regarding CO₂ reduction, low emissions, and possible cost savings are based on preliminary test results and field experience, and are currently being further assessed and validated by independent parties.

No. The 35 kW is classified as an emergency/standby generator and falls under SCIOS (≤500 hours/year). Applications such as prime power or peak shaving do not apply to this model. For those use cases, please refer to the 120 kW model / AquaVolt (in development).

In line with the SCIOS classification, the limit is a maximum of 500 operating hours per year, including test runs.

The generators are currently only available through pre-registration. The expected delivery time is approximately 6 months, subject to final approval and completion of additional certification and documentation for the European market.

A CE Declaration of Conformity is available for the 35 kW version. Additional documentation and certification for full market deployment in Europe — including emissions and safety assessments in accordance with EU legislation — is currently in preparation.

🔹 Energy-Limited Areas: Locations with (temporarily) limited grid capacity
🔹 Events: Festivals, concerts, and outdoor activities where quiet, clean power is needed
🔹 Emergency Backup: Backup power during grid outages
🔹 EV Charging Stations: Temporary or mobile charging stations
🔹 Construction & Infrastructure: Power for tools, lighting, and temporary energy needs

🔹 Fossil-free: powered by a biogenic ethanol mix derived from renewable sources such as sugarcane or agricultural waste.
🔹 Lower emissions: internal tests show virtually no black smoke or diesel odor.
🔹 No Additional Emission Systems Needed: No particulate filter or AdBlue required
🔹 Reduced maintenance: less carbon buildup and cleaner oil may result in lower maintenance needs.

Note: These benefits are based on internal testing in the US; validation according to European standards will follow later.

Based on internal testing, the clean combustion of AquaStroke® does not require diesel particulate filters, catalytic converters, or AdBlue. Note: European validation will follow later.

🔹 Fewer Filter Replacements and Regeneration Cycles
🔹 Cleaner Oil for Longer Periods
🔹 Reduced Wear on Engine Components
🔹 Longer Maintenance Intervals and Lower Costs

Yes. AquaStroke® is modular and can be linked with multiple units or integrated with batteries, solar panels, and microgrids for hybrid applications.

🔹 Construction & Infrastructure
🔹 Events & Recreation
🔹 Industrial Applications
🔹 Commercial Buildings
🔹 Medical Applications
🔹 Sustainability Projects
🔹 Off-Grid Locations & Defense
🔹 Transport & Marine

These models are in development and intended for heavier/continuous applications (with DC fast charging for AquaVolt). Availability and deployment details will follow after validation and certification.