Proton exchange membrane electrolyzers (PEMEZ) are an attractive technology choice as the principal piece of equipment in power-to-gas (P2G), however their usage within the context of P2G has not yet been thoroughly investigated, and no pilot plants for power-to-gas with PEMEZ have as yet been realized in the United States. In this study, a PEM electrolyzer was modified to have dynamic dispatch capabilities, then subsequently operated and studied in detail as a part of the UC Irvine P2G demonstration. The system operated at sustained part load conditions and load followed variable renewable energy resources. Furthermore, the impact on emissions due to the addition of hydrogen to the high pressure natural gas fuel feed to the University of California Irvine (UCI) Central Plant’s combustion turbine is analyzed.

Solar PV load following was found to have minimal impact on system efficiency in producing hydrogen from electrolysis, however wind load following did result in sustained low load conditions that did impact system efficiency significantly. Reduced efficiency due to sustained low part load conditions could be circumvented by cycling PEMEZ off completely and starting up as the load signal reached the minimum effective point again. The effective compression of hydrogen electrochemically in the PEMEZ was demonstrated to nearly match the efficiency of ideal isothermal compression using a semi-empirical model developed from sustained part load operation testing of the PEMEZ.

Addition of hydrogen to the natural gas fired combustion turbine showed very little likelihood of impact on emissions of criteria pollutants (CO, NOx). A slightly significant correlation between reduction in natural gas usage, and by extension emissions of CO2, was noted.

Decarbonizing the power generation sector will indisputably need massive amounts of generation resources and infrastructure upgrades. University of California (UC) campuses throughout the state are considered, each with their own geographical and technological characteristics. The maximum photovoltaic (PV) potential for each campus is identified, an integration strategy evaluated, and the remaining off-campus resources identified to justify a claim of 100% clean electricity. The limited on-campus photovoltaic solar potential and emissions from natural gas fueled plants, where present, require additional projects to generate renewable electricity certifications and carbon offsets. Achieving carbon neutrality for scope 1 and 2 emissions requires accounting for campus fleets and independent heat generation, both of which are relatively minor relative to combined heat and power production.

Entities like the UC that desire to achieve carbon neutrality may generate demand for hydrogen as a clean fuel, instigating large amounts of centralized solar PV plants cited in remote areas. A generalized case comparing the transmission of large amounts of renewable energy as hydrogen in pipelines is compared to the traditional pathway of electricity delivery through power lines. For scenarios in which minimal energy storage is necessary, the electric pathway yields a lower system cost. However, if the state reaches high renewable penetration levels, power from storage must be available for more hours of the year. In this case, the lower cost of storage from geological hydrogen storage and the innate storage capability of pipelines suggest a lower system cost for hydrogen production and delivery despite the lower pathway efficiency.

Recent developments in the area of SOFC electrolyte materials has allowed for the creation electrolyte material sets that can be operated at lower temperatures than their traditional counterparts. By allowing lower temperature operation of SOFCs, these novel material sets introduce a potential vector for cost-savings in fuel cell design by adding potential solutions to several key challenges that face SOFCs such as reductions in: support material costs, insulation thicknesses, thermal mismatch, startup and cool-down wear on the system, and many of the (temperature dependent) SOFC degradation mechanisms. Even though the material sets are still in development, and always evolving as the general understanding of ceramics expands, existing materials are already starting to show potential to dramatically change the way in which we utilize SOFCs today.

This study focused on the development of a dynamic, spatially resolved MATLAB-Simulink model to aid in the design, analysis, and control of LT-SOFC systems. The model developed was organized to allow for study of the challenges of integrating a fuel cell system where the reformer temperature is significantly higher than the operating temperature of the cell itself. While the primary focus of the study was to investigate a single potential design that properly utilizes the temperature dynamics of a low temperature system across a wide range of test cases, a library of building blocks was created to allow for investigation into any number of design orientations or test cases in order to promote future work on the subject.

The growing market for clean, sustainable energy systems has opened to door for many technologies in both the power generation and transportation sectors. Fuel cell technology has provided a means to produce power and heat more efficiently and with fewer emissions than traditional power generation systems. The emergence of hydrogen fuel cell vehicles has demonstrated the use of fuel cells for transportation that use hydrogen fuel to achieve comparable performance to traditional vehicles while achieving greater efficiency and zero emissions. This thesis focuses on a system that brings the two sectors together by utilizing fuel cell technology to tri-generate three useful products from a renewable biogas stream: power, heat, and hydrogen. The hydrogen produced is then directly used at a fueling station to refuel hydrogen fuel cell vehicles. A fully operational system has successfully demonstrated this technology at the Orange County Sanitation District which provided the inspiration for this work. A dynamic tri-generation system has been modeled with investigation of electrochemical hydrogen separation to produce high purity hydrogen necessary for fuel cell vehicles. Results from this analysis show a wide range of design and operational values to characterize the performance under many conditions. Electrochemical separation has unique operation compared to other separation methods and can improve system performance especially in sub megawatt systems. It is shown that tri-generation systems have great promise as an energy system because of their efficient operation, near zero emissions, ability to run on renewable biogas, and the ability to produce the hydrogen fuel for fuel cell vehicles.