Fuel Cell Powered Chevrolet Equinox. Image obtained with thanks from svacher from Flickr.
Introduction to the Problem
You, like most people, may already be familiar with the fact that electric vehicles have a relatively short driving range compared to traditional gasoline powered vehicles.
Most people do not need to drive more than 40 miles per trip, but range anxiety is a problem helping to prevent the widespread adoption of electric vehicles.
People in general would like to have a driving range significantly more than the distance they usually drive, just in case they have to drive far, which is perfectly understandable.
This issue can be addressed, albeit with consequences using a gasoline or diesel fueled backup generator that can either charge the vehicle’s batteries, directly power the vehicle’s motor if the battery dies, provide additional power to the motor if necessary, or combinations of what I mentioned above.
One consequence of including a generator in an EV is that it increases the weight of the vehicle, it lowers efficiency and degrades performance. Another important consequence is that the generator is expensive, so it increases the initial cost of the vehicle and scares consumers away.
One of the benefits of a backup generator is that it can extend driving range to several hundred miles. Chevrolet did this with the Volt. Volt owners enjoy peace of mind because they can drive even farther than they could in a traditional gasoline only vehicle which provides a range of 300 miles.
Now, back to reality: Gasoline fueled backup generators are expensive and inefficient. They are, however, more efficient than a parallel hybrid gasoline engine due to the fact that they usually operate at their single most efficient speed.
The Invention
Researchers at the University of Maryland have developed a type of generator which they say would not only boost the range of electric vehicles, but also keep CO2 emissions low.
This could boost EV range because the energy density of gasoline is a high 12,500 Wh/kg. This is a member of the solid-oxide fuel cell (SOFC) family, which uses a solid ceramic electrolyte.
Solid-oxide fuel cells can be powered by some readily available fossil fuels such as natural gas, diesel, and gasoline, unlike hydrogen fuel cells.
Traditional solid-oxide fuel cells are too large for vehicles, but they say this new one produces ten times more power for it’s size.
This means that it could be ten times smaller than a traditional gasoline engine and produce just as much power, making it a much more suitable candidate (where size is concerned) for electric vehicles.
Another problem with traditional SOFCs is that they have to be heated to very high temperatures of 900 ⁰C in order to function correctly (this is the operating temperature).
The researchers say that they lowered the operating temperature by hundreds of degrees to 650 ⁰C, which is not only a cheaper and easier temperature to maintain, but cheaper materials can be used.
Higher temperature materials tend to cost more money.
This improvement is impressive, but as is the case with new technologies in general, it could use more improvement. Turning it on and off with each trip would cause too much wear and tear, shortening it’s life, so, for now, it would charge a battery pack. These fuel cells are fossil fueled, so even though they could help to facilitate the adoption of more efficient electric vehicles, they still rely on fossil fuels which are economically and environmentally unsustainable.
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Source: Technology Review
Photo Credit: svacher from Flickr.
