Dr. Colleen Spiegel

The gas diffusion layer (GDL) in a fuel cell can consist of a single layer or a double layer (gas diffusion layer and a microporous layer). The GDL is an essential part of the fuel cell because it causes the gases to spread out to maximize the contact surface area with the catalyst...

When a PV cell is exposed to sunlight, the photons of the absorbed sunlight dislodge the electrons from the atoms of the cell. The free electrons then move through the cell, creating and filling in holes. It is this movement of electrons and holes that generate electricity. The process of converting...

Most of us are familiar with solar cells because we encounter them every day – in calculators, street lamps, and traffic road signs. If these devices have enough light, they can theoretically work forever. Solar or photovoltaic (PV) cells are made up of many individuals cell stacked together. The cell material is a...

Wind power generates electricity by transferring energy from wind to mechanical energy. The principle behind wind turbines is very simple: the energy in the wind turns two or three blades around a rotor. The rotor is connected to the shaft, which spins a generator to create electricity. Wind turbines are mounted on...

Imagine that something that you cannot see can have enough movement to harness energy! From a scientific perspective, air is like any other fluid -- if it can be moved forcefully, the motion provides kinetic energy. In a wind-electric turbine, the turbine blades capture the kinetic energy of the...

Low-temperature fuel cells have historically used CNC-machined graphite as bipolar plates. Graphite’s high-cost, high-permeability, and precise machining processes have presented difficulties for the large-scale market. Due to this, many other materials have been...

Thermodynamics is the study of energy changing from one form to another. Many predictions can be made using thermodynamic equations, and these are essential for understanding fuel cell and electrolyzer performance because these devices transform chemical energy into...

Selecting the appropriate technique to properly characterize the fuel cell is extremely important because it helps the user to understand why the fuel cell is performing well or poorly. These techniques will help discriminate between activation, ohmic and concentration losses, fuel crossover, and...

Hybrid renewable energy power systems are positioned to become the long-term power solution for portable, transportation and stationary system applications. Hybrid power systems are virtually limitless in possible setups and configurations to produce the desired power for a particular system. A hybrid system can consist of...

There are many novel hydrogen methods that are currently being investigated that offer the potential for higher energy density than conventional methods. These include hydrogen storage in carbon nanotubes. Carbon nanotubes are unique structures with exceptional electronic and...

A biological fuel cell (BFC) or microbial fuel cell (MFC) is a type of fuel cell that converts biochemical energy into electrical energy. Like other types of fuel cells, a biological fuel cell consists of an anode, a cathode, and a membrane that conducts ions. In the anode compartment, fuel is oxidized by microorganisms, and the result is...

The first step in building a fuel cell is to determine the power requirements needed to power the particular device or application. Fuel cells can be used to power anything including phones, laptops, automobiles, buses, houses, businesses and even space shuttles! A single fuel cell can be designed to achieve any current required for a particular application by merely increasing or decreasing the size of the...

Fuel cells with polymer electrolyte membranes are appealing because of their low-temperature operation and relatively simple construction. The polymer electrolyte membrane (PEM) fuel cell consists of two catalyst electrodes (the anode and cathode) separated by polymer electrolyte. Gaseous fuels are fed continuously to the anode (negative electrode), while...

Fuel cells produce electricity from reactants such as oxygen and hydrogen -- although other fuels besides hydrogen can be used. The electrochemical reaction produces water and heat as byproducts. Fuel cells are much more efficient than the internal combustion engine because they provide more...

There is an acute need for the development of long-lasting, efficient and portable power sources for further technology improvement in automobiles, commercial electronics devices, military and stationary applications. These systems all require the power source to be energy-efficient, and able to operate for long periods of time without...