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Reena Obediah, team manager for the braking/steering system, sits inside the zero-emissions vehicle with Professor Tai-Ran Hsu, the senior project supervisor.

Mobilizing green tech

SJSU team creates award-winning zero-emissions vehicle

By: John Ellis

Posted: 12/4/08

Think the Flintstones meet the Jetsons.

After 40 years of challenging universities to create a marketable human-powered automobile, the Society of Mechanical Engineers has yet to reach its goal.

Imagine a vehicle with an electric motor, four solar panels and eight eco-friendly batteries attached to a custom frame with two sets of power-generating foot pedals.

"I asked myself, 'Why not?'" said Tai-Ran Hsu, a professor of mechanical and aerospace engineering. "Using solely human power isn't practical enough for today's society."

Hsu's answer to the 40-year-old question is a collision between green and human-powered technologies. The result is a new class of energy-efficient automobile destined to get consumers' feet pumping away from gas stations.

"You can't go on the freeway, but you don't need gas," said Yusuf Ali, a mechanical engineering graduate student.

The student-designed zero-emissions vehicle, dubbed ZEM, incorporates a pedaling system that initiates movement and generates storable power, as well as solar and electrical systems to back up the human element.

"It's based on human power and sustainability for the environment," said Hsu, who helped lead the project.

The ZEM vehicle moves at lower speeds when using the pedal- and solar-powered systems, and drives up to 35 mph when the electric motor is engaged, Hsu said.

DESIGNING THE FUTURE

The hybrid human-powered car is the final product of a three-year research, design and construction venture undertaken by mechanical and electrical engineering students for their senior projects.

The project went through three phases, Hsu said. The first phase was the design and construction of a single-seat, three-wheel, solar- and human-powered vehicle, now referred to as the mini-ZEM. The second phase consisted solely of the design of the two-seat, dual-pedaled ZEM model.

It won the $15,000 first prize at the 2007 "Idea-to-Product Competition" held at Purdue University. The third phase was the construction of the award-winning design.

"It looks bulky, but it is really easy to drive," said Reena Obediah, a senior mechanical engineering student working on the project. "I was impressed by how smooth the pedaling was."

URBAN USAGE

Hsu said that ZEM isn't intended to replace all vehicles. Instead, it's meant to relieve heavy traffic congestion within cities and provide a greener option for off-street locations such as campuses and resorts.

"It is a great value for urban commuting," Hsu said. "Even more for light duty work, like for the post office or UPS."

The ideal consumers are targeted as people living in highly populated areas in industrialized and developing countries, Hsu said.

"Congested urban cities in developing countries have big ecological footprints," Hsu said. "The (ZEM) would mitigate their use of sustainable vehicles."

Obediah, the project manager for the steering and breaking systems, added that the ZEM could be used in numerous locales.

"It would be great on college campuses, for maintenance crews, convention centers - even hotels and golf courses," she said.

Even if pedaling a motorized vehicle may be construed as extra work, it doesn't mean that work crews are against the idea.

"I like going green," said Leroy Barnett, an SJSU building services engineer. "When it's practical and functional, I can get with it. But sometimes green can cost you money."

Hsu said the ZEM vehicle is developed to be affordable for everyone. It can be mass produced for a retail price of around $4,000 with very little maintenance needed, he added.

"I wonder how people will transition to it," said Lauren Caldwell, a senior kinesiology major. "It's an interesting idea, but I don't know if people are ready for it."

Yolanda Torres-Kirkpatrick, a junior environmental studies major, said that in the developing world, the vehicle might be more utilized.

"You see what they can do with just a bicycle," she said. "Imagine what they can do with something like this."

Unlike other electric automobiles, the pedal system offers one feature that is expected to keep it on the road.

"With the pedals, you will never get stuck," Hsu said. "If you run out of power, you can always pedal home."

Hsu pointed out another benefit of the unique pedal system: physical activity.

"If you're in a congested street, you might as well get some exercise," he said.

TECHNOLOGICAL INNOVATION

The ZEM is the first vehicle powered by human, solar and electric energy, according to the team's Web site.

The vehicle also utilizes industry-leading, solar-generation panels and locally designed, eco-friendly batteries. The team chose sponsors that complemented its environmentally conscious ideas.

SunPower Corporation of San Jose provided the team with four solar panels. The ZEM has a real-world rating of 18 percent, meaning 18 percent of the energy absorbed can be used.

Hsu said that solar-powered vehicles are becoming realistic options because the technology is improving.

"It's getting better. Conversion rates were 10 percent. Now they're 21," Hsu said. "That can be doubled in 10 years, and that would supply half of the power needed to drive the vehicle."

Clean Battery Technologies Inc. of Santa Clara provided eight 12-volt batteries used in the vehicle. The company recently developed silicone-based batteries that do not use sulfuric acid, which is present in the environmentally hazardous batteries used in mainstream hybrids, such as Toyota's popular Prius hybrid.

Ali noted that when most batteries drain down to a certain level, they can never be fully charged again.

"The batteries work really good," Ali said. "One of the batteries was drained and it went back to a full charge."

GREEN OBJECTIVE

The objective of the project was to produce a marketable human-powered vehicle that would attract investors and provide students with vital, real-world experience, Hsu said.

The ZEM team had to make sure the parts fit the right way and procure the best price possible.

"As a team, we collaborated with people and companies, dealing with different vendors for all the little stuff and custom parts," Obediah said.

She said the team worked with eight companies just in Northern California.

While the patent for the ZEM is still pending, the vehicle's design may suit even the most eco-savvy buyer. The patent covers six aspects of the vehicle, including the ZEM's original electrical system and transmission.

The engineering department is set to reveal a commercial-grade prototype of the ZEM in a celebration on Dec. 5.

"We welcome any commercial interest," Hsu said.

SUSTAINABLE AWARDS

Professor Hsu and undergrad Obediah, who has spent more time on the project than any other student, will be honored at the Dec. 9 San Jose City Council meeting.

They are expected to receive an award from Mayor Chuck Reed on behalf of the SJSU College of Engineering for its work on the ZEM vehicle.

"I'm very excited," Obediah said. "But I'm not exactly sure what it's about."

"It's a good idea," said Katie Doyle, a senior communications major. "But I don't think some people will get it or want to use it."