Students strive to create clean energy future
On a cold January day, the Future Energy Challenge (FEC) team gathered atop Engineering Hall seeking answers to the world's energy problems with a World-War-ll-era ship mast and a modern wind turbine. The team has another turbine mounted on a century-old water-pumping wind tower and yet another that connects to an extension ladder that stows neatly under its tiny, red, three-wheeled Corbin Sparrow. It is the clean, carbon-free energy gathered by the Sparrow's wind turbines and solar panel that gives the vehicle its new name — the "Zero Carbon Car."
Built in 2001 by Corbin Motors in California, the single-passenger electric commuter is six feet long and weighs less than 1,400 pounds. It was one of about 200 built before the company closed its doors in 2003. A UW-Madison alumna and her husband donated the vehicle to the college in 2002. It is one of two projects that FEC students work on to gain hands-on experience with advanced technologies — technologies that hold some of the answers to the world's growing hunger for energy.
The team modified the Sparrow by adding high-tech batteries, a hydrogen fuel cell, wind generator, solar panels and by designing the related power electronics to make it all work together.
"We call it the 'Zero Carbon Car' because it can run on energy that has no carbon-based emissions that contribute to global climate change," says team mentor and WEMPEC researcher Ted Bohn. "It has no engine or tailpipe. Its primary moving part is the motor which drives the rear wheel directly via a belt similar to the belt used on a Harley Davidson."
In addition to its advanced nickel-metal-hydride batteries, Bohn says the zero-carbon Sparrow stores hydrogen in what amounts to a "metal sponge" made of nickel. Hydrogen gas from the sponge enters the 1.2-kilowatt fuel cell and combines with oxygen from the air to make electricity. Clean water is its only by-product. In the fuel cell, a special catalyst material called a proton-exchange membrane allows hydrogen protons to pass along one path while forcing electrons to form the electrical current that drives the motor. The fuel cell itself has no moving parts.
Hydrogen as a fuel is only as clean as the technology used to produce it. The team is working with Madison's Virent Energy Systems, Inc. to supply the Sparrow with hydrogen fuel derived from sugars. (Virent Energy Systems was formed to commercialize the "aqueous phase reforming" process, a carbon-neutral method for on-demand production of hydrogen and fuel gas. The technology was developed in the College of Engineering.)
"The car also carries a small wind generator and solar panel that can be set up while the vehicle is parked. Most vehicles are parked most of the day," says Bohn. "The idea here is that typical automobiles produce regulated tailpipe emissions as well as unregulated greenhouse gas emissions, including carbon dioxide. A solar/wind/hydrogen-powered car, such as ours, has potentially zero carbon emissions. That makes it a good step toward cleaner transportation in the future.
The team's efforts and innovation garnered first place in the hydrogen vehicle category at the 2004 Tour de Sol. The team will compete in the event again this coming May.
The FEC's second project involves a competition to design and build a utility-interactive inverter system for small, distributed energy generation. This relates to the Sparrow because such a system is required to collect clean energy from a multitude of sources, such as wind and solar, and then safely feed it to the electric utility system. It's a tall order.
The inverter must comply with requirements for harmonic control, interconnection and safety standards. It must also be able to operate in typical voltage and frequencies, either grid-connected or stand-alone, and its total hardware costs are targeted to $200. The unit must operate from a varying dc input voltage (30 volts to 60 volts) under varying constrained input power (250W to 1000W) to a single-phase utility line (110/240V either 50Hz/60Hz) with efficiency of at least 90 percent.
The College of Engineering's team finished in the top five out of 12 teams competing in both the 2001 and 2003 Future Energy Challenge student design competitions. The team is preparing to compete in the 2005 competition this coming August at the National Renewable Energy Laboratory in Golden, Colorado.
The technology of the Future Energy Challenge captures most of the attention. But to focus on the innovations alone would be to miss the point. It's not so much about how to meet the challenge as it is about who is meeting the challenge. The students working toward answers today are clearly the solution to how we make energy in the future.
"The Future Energy Challenge is important to me because I would ultimately like to get a job doing exactly what we are working on in the challenge," says FEC team leader Curtis Roe.
"I would like to see renewable energy become much more popular and widespread. This is my goal now and after my graduation in May."