Open Water Power has developed a novel aluminum-water platform technology for undersea power generation. Invented and patented by our founders at MIT, the electrochemical system provides safe, scalable & non-toxic energy storage with extremely high energy density, promising a 10x improvement in the endurance of Unmanned Underwater Vehicles (UUVs) and sensors.



Our Technology

Open Water’s technology harnesses the significant electrochemical energy stored in aluminum metal. While a variety of technical hurdles have traditionally made this energy difficult to access, our proprietary and patent-pending technology overcomes these issues. In addition to improved energy densities, the aluminum-water chemistry is inherently safer and more stable than many other battery and fuel cell chemistries typically found in maritime use. Prior to activation our systems are chemically inert, with no risk of explosion and a virtually unlimited shelf life. Once our systems are activated with water, their safety profile is similar to that of household alkaline batteries. The Naval Surface Warfare Center at Carderock recently conducted preliminary safety testing of some of our cells and found them to be inert over a range of abusive conditions that would typically cause lithium-ion and even silver-zinc batteries to fail dangerously. The public-release report of their testing is available here; a summary of results can be found on Slide #12.

Energy Densities

Cell-Level Energy Density and Safety

The graphic below depicts the effective cell-level energy density of Open Water’s technology vs. various other energy storage technologies typically found in underwater applications. The graphic also contains a subjective, qualitative metric of the technology’s safety. The graphic demonstrates the general trend that the more energy-dense a technology is, typically the more dangerously it can fail. The graphic shows that Open Water’s technology is an exception to this trend.

System-Level Energy Density

The first graphic below depicts the system-level energy densities of Open Water’s technology vs. various energy storage technologies for maritime use. The graphic contemplates the two common design scenarios in subsea system design: where neutral buoyancy is required (e.g. in UUVs), and where it is not (e.g. ocean-floor sensors and systems). The system-level energy density of Open Water’s neutrally buoyant systems is aided by our ability to use as a buoyancy compensation media the hydrogen byproduct that is generated by our reaction. Hydrogen offers a lower (i.e. better) density at all depths than syntactic foams and alternative gasses, as the second graphic illustrates. Furthermore, our chemistry’s continuous production of hydrogen at negligible gauge pressure allows us to control buoyancy dynamically using only lightweight bladders and plumbing, turning UUVs equipped with our power systems into powerful hybrid gliders.

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The hydrogen gas produced by Open Water’s chemistry can be used as a buoyancy media. Hydrogen has a density that is lower than foams and other gasses, requiring less volume for a given level of buoyancy. This is an added contributor to Open Water’s high system-level energy densities for systems requiring neutral buoyancy.

Current Development Status

Open Water’s core chemistry is fully developed. We have run large-scale cells for over a week and smaller-scale low-power cells for months. Our focus now is on systems integration: building full-up power solutions for extant platforms and fielding them (e.g. man-portable UUVs, ocean-floor sensors, and sonobuoys). In this light we say that our Technology Readiness Level is TRL 6 on a cell level and TRL 4 on a system level. Specifically, our prototype cells have been tested on the benchtop using lab-grade pumps, electronics, and monitoring equipment, but they are run on real seawater, at environmental temperatures, generating operationally relevant power levels.
We have demonstrated cell-level energy densities in excess of 2.0 kWh/L and sustained power densities of up to 35 W/L, with higher power available in bursts. At a recent conference at the Woods Hole Oceanographic Institute (WHOI) we debuted our first public demo, which allowed users to interact with running cells by varying the load and monitoring the cells’ performance. We followed that a few weeks later with a 3-day live demo at the OCEANS ’16 conference in Monterey, California. The video below shows the OCEANS ’16 demonstration. The system consisted of our cells in a tank driving a UUV motor and prop, and a controller by which visitors to the booth could adjust the power output of the cells and watch the prop speed vary accordingly.
Open Water holds a prime contract with the US Department of Defense to develop power systems for man-portable UUVs. We hold a separate contract with NAVSEA for the development of an ocean-floor power system. We are working with corporate partners on other platforms. Our technology’s performance makes it a great fit for UUVs, ocean sensors and manned submersibles of all sizes. We are not a good fit for extremely high sustained power-density systems like torpedoes, nor are we a good fit, because of our water-based chemistry, for high temperature applications like downhole drilling. But if your application requires long-duration, moderate power underwater, our chemistry’s performance is the best in class.

Use Case

From both an operational cost and a strategic point of view, current UUV use is limited by the need for manned surface and submarine support vessels for deployment, operation & retrieval.  A significant increase in the range of UUVs would allow many operations to be conducted by UUVs launched directly from shore, without the need for a support vessel and its crew.  An example from the oil & natural gas industry is depicted below, illustrating how significant of an impact Open Water’s technology could have on such operations.

Oil & Gas Operations in the Gulf of Mexico:

Current vs. potential out-and-back ranges for a standard 21″ UUV in the Gulf of Mexico. Current UUV range (red circles) is insufficient to reach the vast majority of pipeline assets and lease blocks. The same standard UUVs powered by Open Water’s technology would offer complete coverage (gray area) of the Gulf’s resources, enabling fully autonomous ocean floor surveying, pipeline inspection and well monitoring for virtually all assets in the field, requiring little more than shore launch & recovery at, for example, Galveston, TX and New Orleans, LA.

What the Market is Saying

Low-cost, high energy density, safe, reliable, long-duration power sources are needed in all categories
-US Navy: UUV Master Plan
[Current] power and energy technologies for traditional, torpedo-like AUVs are deemed immature
-RAND: A Survey of Missions for UUVs
“The interplay of launch and recovery capabilities with vehicle endurance will be a crucial factor in the commercial success of AUV systems
-BP: Application of AUV Technology in the Oil Industry