Generation of Hydrogen from Seawater, Powered by Solar PV, Leading to Cogeneration of Electricity and Potable Water

Navy SBIR 20.2 - Topic N202-123

Naval Facilities Engineering Center (NAVFAC) - Mr. Timothy Petro timothy.petro@navy.mil

Opens: June 3, 2020 - Closes: July 2, 2020 (12:00 pm ET)

 

 

N202-123       TITLE: Generation of Hydrogen from Seawater, Powered by Solar PV, Leading to Cogeneration of Electricity and Potable Water

 

RT&L FOCUS AREA(S): General Warfighting Requirements (GWR)

TECHNOLOGY AREA(S): Chem Bio Defense, Materials

 

OBJECTIVE: Develop a shore-based system with durable components that can be used to generate hydrogen from seawater using variable solar photovoltaic (PV) power with the purpose of producing usable electricity and potable water. (Note: The system design should take into consideration lifecycle cost effectiveness and minimizing potential contaminants from the component material into the generation of water.)

 

DESCRIPTION: In order for renewable energy to provide greater resilience benefits to the Navy, Marine Corps, and throughout the U.S., its variable power output must be coupled with energy storage. Development in this area focuses on electric power and ignores potable water requirements, which are arguably a bigger limiter for continuation of mission operations when the utility supply is unavailable. Energy storage involving hydrogen often produces water as a byproduct of its power generation process. Hydrogen generated from seawater has yet to be commercially viable due to the high cost of materials, short product life of components, and low efficiency of the seawater-to-hydrogen evolution process. Studies and developments over the past 5-10 years have shown different yet effective ways of generating hydrogen that is compatible with seawater and address some of the major corrosion challenges [Refs 1, 2, 3]. Combining the two hydrogen-related processes into one system and utilizing variable renewable power can provide a greater resilience benefit for both island and coastal military installations, even for those that already have on-site power and water generation capabilities. Overcoming past and current issues with hydrogen generation, including corrosion, chlorine, and expensive materials, will improve lifecycle cost effectiveness. Designing the system to be used to generate potable water will affect its design as to reduce or eliminate potential water contamination.

 

PHASE I: Develop and demonstrate the subsystems capable of using real or simulated variable PV power and determine at least one source of real seawater from which to generate hydrogen and convert hydrogen into electricity and water. Evaluate attributes of the system, including energy density, power density, transient dynamics, system size and efficiency, water production rate and quality, component product life, and anticipated maintenance requirements using detailed models and subscale components. The U.S. Environmental Protection Agency (EPA) safe drinking water requirements for States and Public Water Systems shall be a starting point for establishing thresholds for defining potable water and target potable water production to at least 6 L/kW [Ref 4]. Finalize the systems integration and design for a 10kW-level test-bed prototype to be used for Phase II. Provide a Phase II development approach and schedule that contains discrete milestones for testing and further development.

 

PHASE II: Fabricate a test-bed 10 kW-level prototype. Validate prototype capabilities using laboratory testing and at least two sources of seawater with known major differences that can potentially affect the function and output of the system. Further evaluate attributes of the system from Phase I. Design a fully functional 10kW system that can be fabricated and tested in a non-laboratory environment. As funding permits, work toward fabrication of a fully functional system.

 

PHASE III DUAL USE APPLICATIONS: Fabricate and test a fully functional system in a real-world environment. Acquire certifications necessary to comply with connecting to a shore-based, utility grid system. Develop documentation, such as a DD-1391 and eROI (Energy Return on Investment), for sites with high potential for this application to enable the installation to request funding for construction. While this system will benefit island and coastal military installations, it can also find applications in municipalities and community microgrid systems especially where water and power are unreliable or require an alternate source. In addition, it can support a hydrogen economy or be applied to hydrogen powered vehicles.

 

REFERENCES:

1. Garcia de Jesus, Erin. “Stanford researchers create hydrogen fuel from seawater.” Stanford News, March 18, 2019. https://news.stanford.edu/2019/03/18/new-way-generate-hydrogen-fuel-seawater/

 

2. Hristovski, Kiril, Dhanasekaran, Brindha, Tibaquirá, Juan E., Posner, Jonathan D. and Westerhoff, Paul. “Producing drinking water from hydrogen fuel cells.” Journal of Water Supply: Research and Technology – AQUA, Volume 58, Issue 5, July 2009, pp.327.335. https://asu.pure.elsevier.com/en/publications/producing-drinking-water-from-hydrogen-fuel-cells

 

3. U.S. Army CCDC Army Research Laboratory. “Army hydrogen-generation discovery may spur new industry.” U.S. Army website, July 2009. https://www.arl.army.mil/www/default.cfm?article=34794. U.S. Environmental Protection Agency. “Drinking Water Requirements for States and Public Water Systems.” September 2017. https://www.epa.gov/dwreginfo/drinking-water-regulations

 

KEYWORDS: Seawater, Hydrogen, Fuel Cell, Solar Photovoltaic, Potable Water