Archive for November, 2010
Torrington Stop & Shop using fuel cell
The Torrington Stop & Shop Supermarket on East Main Street installed a 400-kilowatt fuel cell on Monday, providing 94 percent of the store’s needed electricity.
Published Nov 24, 2010.
Read more: Hartford Business Journal
Hydrogen Fuel Cells
Hydrogen fuel cell technology promises to help us deal with the dwindling supply of fossil fuel. But how far away is this technology for you and me?
Aren’t you tired of the high price of gasoline for your car? Not to mention your concern for the environment. Well, a solution to both of these concerns may be just around the corner. For years, scientists have being working on an alternative energy source that promises to change the way we live by changing the source of fuel for some of our most basic energy-using engines. This new technology is called a fuel cell, and it’s based on using water as the original source of the fuel! A fuel cell provides a DC (direct current) voltage that can be used to power motors, lights, or any number of electrical appliances–including cars.
The technical name for a fuel cell is an electrochemical energy conversion device. You’ve actually been using one for many years, which is a battery. All batteries are electrochemical energy conversion devices.
But hydrogen fuel cell technology is a new twist on an old theme. Here’s the basic idea of how it works:
A fuel cell converts the chemicals hydrogen and oxygen into water, and in the process it produces electricity. The difference between a simple battery and a fuel cell is that all the chemicals are stored inside the battery. The battery converts those chemicals into electricity but eventually it “goes dead” as the chemicals are used up. So you end up either throwing it away or recharging it.
On the other hand with a fuel cell, chemicals constantly flow into the cell. So as long as there is a flow of chemicals into the cell, electricity flows out of the fuel cell. Simply put, a fuel cell releases electrons from the hydrogen gas, creating electricity with the waste product being pure water! The electricity is used to power an electrical device–like the electric motor to run your car.
In an internal combustion engine, the gasoline engine burns gas and the battery converts chemical energy back into electrical energy when needed. However, fuel cells should do both tasks more efficiently.
This reaction in a single fuel cell produces only about 0.7 volts. To get this voltage up to a reasonable level, many separate fuel cells must be combined to form a fuel-cell stack.
One problem with using hydrogen is that it is not easily stored for consumer use. Other alternatives could be natural gas, propane, and methanol gas. But the primary objective of using fuel cell technology is pollution reduction. The fuel cell is also very efficient. Around 80% of the fuel used in these hydrogen fuel cells is converted into usable energy compared to only 20% for a gasoline powered engine and about 30% overall for a battery powered electric vehicle.
There is no question that the fuel cell holds great promise for the future. However, many challenges remain, and it’s been predicted that hydrogen fuel cell technology won’t be available for the masses until around 2050.
Originally published here.
Charles Brown
Control of Fuel Cell Power Systems: Principles, Modeling, Analysis and Feedback Design (Advances in Industrial Control)
The problem of greenhouse gas (particularly carbon dioxide) release during power generation in fixed and mobile systems is widely acknowledged. Fuel cells are electrochemical devices offering clean and efficient energy production by the direct conversion of gaseous fuel into electricity. As such, they are under active study for commercial stationary power generation, residential applications and in transportation. The control of fuel cell systems under a variety of environmental conditions and over a wide operating range is a crucial factor in making them viable for extensive use in every-day technology.
In Control of Fuel Cell Power Systems the application of fuel cells in automotive powertrains is emphasized because of the significance of the contribution to global CO2 emissions made by ground vehicle propulsion and because of the challenge presented by the accompanying control problems. The authorsÆ comprehensive control-oriented approach provides:
-Â An overview of the underlying physical principles and the main control objectives and difficulties associated with the implementation of fuel cell systems.
-Â System-level dynamic models derived from the physical principles of the processes involved.
-Â Formulation, in-depth analysis and detailed control design for two critical control problems, namely, the control of the cathode oxygen supply for a high-pressure direct hydrogen fuel cell system and control of the anode hydrogen supply from a natural gas fuel processor system.
-Â Multivariable controllers that attenuate restraints resulting from lack of sensor fidelity or actuator authority.
-Â Real-time observers for stack variables that confer redundancy in fault detection processes.
-Â Examples of the assistance of control analysis in fuel cell redesign and performance improvement.
-Â Downloadable Simulink” model of a fuel cell for immediate use supplemented by sample Matlab” files with which to run it and reproduce some of the book plots.
Primarily intended for researchers and students with a control background looking to expand their knowledge of fuel cell technology, Control of Fuel Cell Power Systems will also appeal to practicing fuel cell engineers through the simplicity of its models and the application of control algorithms in concrete case studies. The thorough coverage of control design will be of benefit to scientists dealing with the electrochemical, materials and fluid-dynamic aspects of fuel cells.