Dr. Colleen Spiegel

Dr. Colleen Spiegel

Dr. Colleen Spiegel is a mathematical modeling and technical writing consultant (President of SEMSCIO) and Professor holding a Ph.D. and an MSc degree in Engineering. She has seventeen years of experience in engineering, statistics, data science, research & technical writing work for many companies as a consultant, employee, and independent business owner. She is the author of ‘Designing and Building Fuel Cells’ (McGraw-Hill, 2007) and ‘PEM Fuel Cell Modeling and Simulation Using MATLAB’ (Elsevier Science, 2008). She previously owned Clean Fuel Cell Energy, LLC, which was a fuel cell organization that served scientists, engineers, and professors world-wide.

Introduction to Electrolyzers

Electrolyzers use electricity to break water into hydrogen and oxygen. The electrolysis of water occurs through an electrochemical reaction that does not require external components or moving parts. It is very reliable and can produce ultra-pure hydrogen (> 99.999%) in a non-polluting manner when...

Fuel Cell Gaskets, Spacers, and End Plates

Most people wouldn’t think that much thought needs to be put into fuel cell components such as fuel cell gaskets, spacers, and end plates, however, every part of the fuel cell stack requires careful consideration. Incorrect fuel cell gaskets and end plates can lead to gas leaks and insufficient fuel cell stack...

Materials Used for High-Temperature Fuel Cells

In a previous blog post, we described bipolar plates and the associated materials for low-temperature fuel cells. The materials previously described are selected for fuel cell stacks at or slightly above room-temperature -- which means that the materials are chemically compatible with the stack between 0 – 140 °C. The fuel cells that operate at higher temperatures require...

Flow-Field Design

In fuel cells, the flow field plates are designed to provide an adequate amount of the reactants (hydrogen and oxygen) to the gas diffusion layer (GDL) and catalyst surface while minimizing pressure drop. The most popular channel configurations for PEM fuel cells are serpentine, parallel, and...

Low-Temperature Bipolar Plates

Each component of the fuel cell must be designed properly – otherwise, you run the risk of decreasing fuel cell performance. The bipolar plates are termed “bipolar” because they have flow fields on both sides. This design is very convenient when you have membrane electrode assemblies (MEAs) on both sides. In a fuel cell with a...

Fuel Cell Modeling

After you understand the basic concepts around designing, building, and testing fuel cells, the next step is optimization. Optimization often involves extensive experimentation and testing, however, sometimes experimentation does not yield the expected results. Mathematical modeling is useful when phenomena cannot be visually...

Electrical Subsystem of Fuel Cells

If you took the electrical output directly from a fuel cell, it would be an unideal power source. The output of a fuel cell is a DC voltage that varies widely and has a limited overload capacity. The electrical output is slow to respond to load changes because it is based on a chemical reaction, and may have...

Techniques for Measuring Fuel Cell Resistance

The fuel cell polarization curve provides useful information on fuel cell performance, however; additional information is needed to study its performance characteristics accurately. Cell resistance provides insightful information about a fuel cell that is not completely captured by polarization curves. Since fuel cell current densities are high in comparison with...

Water Management For PEM Fuel Cells

One of the greatest challenges associated with PEMFCs is the water balance in the fuel cell stack. As the chemical reaction occurs in each cell, water is generated. Depending upon the load and the operating conditions, there is a tendency for the fuel cells to both flood and dry-out. The water content in the...

Fuel Cell Heat Management

Creating high-efficiency fuel cells requires proper temperature control, and heat management to ensure that the fuel cell system runs consistently. Depending upon the fuel cell type, the optimal temperature can range from room temperature to 1000 ºC, and any deviation from the designed temperature range can result in...

Polarization Curves

If you work with fuel cells, then you are definitely working with polarization curves. The polarization curve does not have a lot of specificity; however, it is one of the most common methods of testing a fuel cell. It also allows an easy comparison to other published polarization curves. The polarization curve displays the voltage output of the fuel cell for a given current density loading...

Fuel Cell System Design

Fuel cell system designs range from very simple to very complex depending upon the fuel cell application and the system efficiency desired. A fuel cell system can be very efficient with just the fuel cell stack and a few other balance-of-plant components or may require many outside components to optimize...

Fuel Cell Characterization

Different characterization techniques enable the quantitative comparison of every property and part of the fuel cell stack. By characterizing the fuel cell properly, you can understand why the fuel cell is performing well or poorly. These techniques help discriminate between activation, ohmic and concentration losses, fuel crossover, and...

Fuel Cell Operating Conditions

Fuel cell operating conditions depend upon the cell and stack design. The operating parameters that affect fuel cell performance are: Operating Pressure, Operating Temperature, Flow Rates of Reactants, and Humidity of Reactants. Using the correct operating condition for each parameter is...

Alternative Liquid Fuel Types for Fuel Cells
Fuel cells usually use compressed hydrogen as the fuel; however, there are many liquid fuels that can be used with fuel cells. Depending upon the system design, liquid fuel types may not be as efficient as pure hydrogen because...