H Power Corp.
These days, news about fuel cells can often be found throughout the media, from The Wall Street Journal to Country Living Magazine. However, the science behind the fuel cell is relatively new to most people, and it can be difficult to follow exactly what the state of the technology is and how that technology applies to the public today–hence, this history and overview of the fuel cell.
Sir William Robert Grove, a Welsh judge, inventor and physicist developed the first fuel cell in 1839. He mixed hydrogen and oxygen in the presence of an electrolyte (a nonmetallic electric conductor), and produced electricity and water. Research was continued over the years by various scientists, culminating in a design that was viable for NASA’s space program in the 1960’s. In fact, today fuel cells are still used on the space shuttle to provide power and drinking water for the crew. The design produced for NASA formed the basis for those currently being explored for private use.
Fuel cells produce power using an elec-trochemical reaction as opposed to a combustion process–as is typical today. A single cell takes hydrogen molecules (H2) and splits them into protons and electrons. The electrons flow through an external circuit to produce power. The protons travel through the cell and meet oxygen (O2) molecules from the air and combine to form water (H2O). (See graphic.)
There are several kinds of fuel cells, each differentiated by the materials that are used and the temperatures at which they operate. The fuel cells most commonly referred to in the news are proton exchange membrane (PEM) fuel cells. Recent advances in the materials they use, as well as manufacturing efficiencies, make PEM fuel cells the most versatile fuel cell technology for commercial applications.
It ain’t just fuel and cells
Since fuel cell systems are most often referred to as simply “fuel cells,” most people do not realize that a completed system is comprised of several sub-systems. At the heart of a fuel cell system is the fuel cell stack. A fuel cell stack is composed of several fuel cells mounted together. The number of fuel cells, design nuances and the materials from which they are produced, determine the amount of electricity that is produced. An electronic controller and a fuel regulation system govern the stack’s performance.
This is the most basic fuel cell subsystem. The power that is produced is typically unregulated direct current; thus, a power conditioning subsystem is required depending on the type of electricity that is required (voltage and current). Additional subsystems may also be added on the output side depending on specific requirements. For example, a sensor module may be incorporated, creating a fuel cell-powered back-up system. To increase overall system efficiency, by-product heat and water can be captured and used to provide hot water and space heating in larger systems.
A fuel cell system requires a flow of hydrogen fuel to operate. The fuel subsystem on the input side is the focus of intense research. Hydrogen can be produced in many ways. Today, it is most often generated as a by-product of industrial processes. Hydrogen is usually stored and transported in super cooled liquid form. It is then distributed in a compressed gas form from various distribution points, including standard gas cylinders and pipelines. It is easy to obtain this form from welding and industrial gas suppliers. Several on-site hydrogen generation sub-systems for use with fuel cells are currently in development. For example, a reformer is a device that uses propane or natural gas to produce hydrogen. Another process under investigation is electrolysis, wherein an electric current is passed through water to separate hydrogen from oxygen.
Fuel cell applications of all kinds are currently under development from micro-sized systems for use in small digital devices to monolithic plants used to power entire communities. While the use of fuel cells is most often discussed within the transportation industry, due to the challenges associated with hydrogen fuel storage, most automakers do not predict mass commercialization until 2010. Given the fact that fuel cells work, and that an existing direct hydrogen infrastructure is already in place, some fuel cell developers have recently launched commercially available systems. These systems usually run on hydrogen provided from standard gas cylinders and are rapidly gaining acceptance in applications such as battery recharging, distributed generation, back up power and remote power generation, to name just a few.
Tony Fatouros is the director of e-business & communications for H Power Corp., a fuel cell development and manufacturing company based in Belleville, New Jersey. He can be contacted at email@example.com or 973-450-4400 ext. 5568. More information can be found at www.hpower.com.
H Power’s considerations for fuel cell shopping
- Fuel cell companies should act as your partner and work with you every step of the way–from application analysis, through fuel acquisition, installation and finally service.
- Verify that the system you are considering is either an advanced prototype or a commercial system. The CSA (Canadian Standards Organization) has recently published a fuel cell standard and some current fuel cell manufacturers have had their systems certified.
- Clarify warranties.
- Analyze the total cost of ownership, not just the capital investment. Factor in features and benefits.
- Ask for, or propose financing options such as leasing. Also, most states offer clean energy credits, financing assistance or rebates for employing “clean” technology such as fuel cells.