Grantee Research Project Results

Final Report: Grid-independent Electricity Generation for Remote Areas Based on a Unitized Hydroxide Exchange Membrane Fuel Cell System

EPA Grant Number: SU834726
Title: Grid-independent Electricity Generation for Remote Areas Based on a Unitized Hydroxide Exchange Membrane Fuel Cell System
Investigators: Tam, Kawai , Yan, Yushan , Contreras, Christian , Hammar, Gregory , Skovgard, Jason , Lee, Joon-Bok , Chiu, Marcus , Chavez, Steven , Vandergrift, Trevor
Institution: University of California - Riverside
EPA Project Officer: Page, Angela
Phase: I
Project Period: August 15, 2010 through August 14, 2011
Project Amount: $10,000
RFA: P3 Awards: A National Student Design Competition for Sustainability Focusing on People, Prosperity and the Planet (2010) RFA Text |  Recipients Lists
Research Category: Pollution Prevention/Sustainable Development , P3 Awards , P3 Challenge Area - Air Quality , P3 Challenge Area - Safe and Sustainable Water Resources , Sustainable and Healthy Communities

Objective:

1. Background and Problem Definition: Currently a quarter of the world’s population does not have access to electricity. This is apparent in rural and remote areas of the world, especially in developing countries. Without access to electricity from a power grid, necessities such as heat, for cooking and warmth, lighting and clean water are much more difficult to attain and must rely on combustion processes that emit pollution. One of the major challenges of implementing sustainable and renewable energy sources such as solar and wind is the intermittent nature of these sources. If a clean, simple energy storage system can be attained, this would be beneficial in further use of these renewable sources.
2. Purpose, Objectives, and Scope: A unitized regenerative hydroxide exchange membrane fuel cell system (URHEMFC) was investigated as a means to store and generate electricity cleanly for remote communities. Unitized regenerative fuel cell refers to a system that can be used as a fuel cell to generate power using hydrogen as fuel, and in reverse as an electrolyzer to split water to generate hydrogen. The key innovation is the newly developed quaternary phosphonium-based hydroxide exchange membrane (HEM), TPQPOH. HEMFCs allow the use of inexpensive catalysts such as nickel and silver in lieu of platinum; significantly reducing the costs of the system.
3. Challenge and Proposed Design Relating to Sustainability: The featured membrane has been previously demonstrated to be efficient in a hydrogen fuel cell. This project demonstrated the capability of this HEM to be used in an electrolyzer and integrate the system into a unitized regenerative fuel cell system. Solar photovoltaic electricity will be used in the electrolysis reaction to generate hydrogen and oxygen. The stored hydrogen and oxygen will then be available to generate electricity in the fuel cell system and resupply the water for subsequent electrolysis. This system uses renewable energy, generates electricity that is applicable to rural and remote areas and generates no pollution.

Summary/Accomplishments (Outputs/Outcomes):

The viability of this concept of using TPQPOH in an electrolyzer was confirmed. TPQPOH HEM membranes of various thicknesses were tested, and an 80-micron thick TPQPOH membrane was shown to produce hydrogen at a sufficient level to power a connected fuel cell over a five-hour period. A laboratory-scale regenerative fuel cell/electrolyzer system powered by three solar cells with a HEM membrane electrolyzer and a commercial fuel cell stack was completed to show the viability of this design. An economic analysis based on the power requirements of a family situated in a developing area with no previous access to electricity Grid-independent Electricity Generation for Remote Areas – Phase II was completed, showing the economic viability of this design. The net payback period of the designed product as a whole is less than one year for such a family, demonstrating the inexpensive nature of the system. An environmental analysis based on a comparison with the smallest possible diesel power generator was used to show the potential of this system to save over 8,800 kg of CO₂ per year, even after including all the cost involved with the initial manufacturing of the system.

Conclusions:

Our system is a combination of both an original discovery (the TPQPOH membrane), and an adaptation of existing knowledge (a regenerative fuel cell). A prototype demonstrating the viability of a TPQPOH-based regenerative fuel cell system has been developed. This system successfully generated hydrogen using a hydroxide membrane as an electrolyzer. Specifically this project has proven the applicability of TPQPOH as a hydroxide exchange membrane for electrolysis. This project has great potential to bring about positive impacts in making progress toward sustainability as it relies on two natural resources, sunlight and water, where water is regenerated throughout the process. This system has great applicability to each element of P3 competition: people, prosperity, and the planet. It not only has the potential to provide an accessible method for third world countries to gain electricity, it also does so in an affordable manner that is completely sustainable and has no harmful emissions to the environment. This URHEMFC completely eliminates the emissions seen by even the smallest of stand-alone diesel and other fossil fuel generators amounting to reductions of 8,800 kg CO2/year that would be emitted from fossil fuel sources. This system produces hydrogen in a completely regenerative manner and with sunlight as its sole input.

The potential impacts are broadly applicable to industry sectors or other situations. Many members from the hydrogen energy sector expressed interest in the results of this project and its potential for further development after the student members placed second in a design of a residential hydrogen fueling and energy production system based on HEM. Support letters from a number of organizations including the Hydrogen Education Foundation, Fuel Cell and Hydrogen Energy Association (FCHEA), American Public Power Association (APPA), Electrochem Inc., Proton Energy Systems, and Riverside Public Utilities are included in this Phase 2 proposal, with a pending letter from Honda Motors. In addition, Mr. John Wells and other members of the off-the-grid living movement in the United States have stated their interest in this project. These supports, in addition to the support we received in the beginning of this project from entities such as Ballard Power Systems, Full Cycle Energy, and Engineers Without Borders are a true testament to the potential held by this project. This system has great potential to bring about large improvement in the quality of life of many people around the world. More than one fourth of the world’s population will gain access to steady illumination at night, clean and safe sources of water, and sanitation.

Supplemental Keywords:

portable energy, clean energy, energy storage, hydroxide exchange membrane, HEM, proton exchange membrane, PEM