Grid Scale, Solar

Bus Uses Sun to Take Alternative Power Miles Ahead

Tom Tripp and Ben Cooper recently set out to make history — again — with one of CARTA’s electric buses.

(condensed from the Times & Free Press, Dec 27) The two men took one of the smallest of CARTA’s electric shuttle buses and added solar panels to its roof, hoping to increase the vehicle’s mileage between electric charges. In doing so they turned the bus, built originally for the city transit company by Chattanooga-based Advanced Vehicle Systems, into a second-generation environmental laboratory on wheels. The trial worked, said Tripp, a Chattanooga entrepreneur who designs alternative power systems sold all over world under the name of Big Frog Mountain. Cooper, special projects engineer for AVS, agreed, adding that solar panels atop the bus roof to gather solar power during the day’s travels extend the vehicle’s range by about 5 to 7 percent. That’s about two bus loops around downtown, he said. “It may not sound like much, but think of it this way,” Tripp said. “That one bus with solar panels saves 1,900 to 2,100 pounds in carbon dioxide emissions a year.” That’s the amount of greenhouse gases that will not be released to the atmosphere in electric power production to fuel the 5 to 7 percent battery charge accomplished by alternative solar power, according to Tripp and Cooper, the system’s designers. In dollar figures, the solar option would add $4,000 to $5,000 to the cost of each new small bus sold, said Cooper. “On bigger buses, we can put double the number of panels and double the energy savings,” said Tripp. “We could offset two tons of emissions a year.” Cooper agreed. “AVS and Big Frog Mountain have the same goal, to provide solutions that will clean up the environment,” he said. And it is good public relations for a lot of customers looking to buy the 100 buses AVS hopes to market in the coming year. Nationwide, solar power as a way to lower energy consumption seems finally to be finding a place in the sun, though the South has been slower than other regions to see the light. “Department of Energy figures estimate that solar panels more than 100 square miles in Texas would produce enough electricity to power the entire United States,” said Tripp. But as the experimental bus shows, it’s no longer necessary to think in terms of one large area. Already, solar systems are increasingly used to power highway signs, railroad warning signals and other outdoor needs. And now with more states signing on to offer tax credits for installations of environmentally friendly and energy-conserving systems, home and business uses are increasing as well. Whether AVS will adopt the solar experiment as one of its new options to offer bus customers in the coming year remains to be seen. Cooper said a decision likely will be reached in the coming week. If company officials don’t approve solar power as a option, the panels on the experimental bus will be deassembled and returned to Tripp. Tripp said his business has increased 350 percent in the past year — mostly to customers in California and other western states. And as the technology improved over the past few decades, the cost of building solar systems is 28 times less than that in the 1970s, he said. That’s one reason Tripp and Cooper are so excited about their mobile solar power trial. “A lot of people all over the country are interested in this project,” said Tripp. “With electric buses, we’ve already got diesel vehicles beat on maintenance costs and environmental benefits. But this now increases their range,” said Cooper. “We already were the first to do that with turbines. So we did the solar thing as an experiment to see how much additional range we can get when we’re on the road.” Seeing the bus with solar panels on top is also a good way to get the word out about the growing uses and technologies of solar energy, he said, adding that CARTA has been a great resource. “Not many companies would loan us a bus and let us attach something into its electrical system.” But highway and vehicle uses aren’t the only advances. Some of the most important changes in alternative power are legislation and devices making it easy to sell excess homemade power generated in home and business uses, Tripp said. Homeowners and business owners now can actually return excess solar, wind or stream-turbine power back to the power grid. And as that process occurs, it turns a power meter backward. The idea is not to put Tennessee Valley Authority or other large commercial power producers out of business, Tripp said. Rather, it’s to conserve energy and help clean up the environment. Alternative power actually helps commercial electricity makers, especially in peak power consumption times. “That’s when they have to fire up more of the coal-fired plants,” said Tripp. “And alternatives can also stop brown-outs,” said Cooper. “It’s our version of green power,” said Tripp. “The difference is, ours lowers the bill as opposed to helping TVA pay for it.” But energy savings does not mean free. A solar system in a typical home can cost thousands of dollars. But Tripp said the first process in designing any alternative power system, even before a home is built, is to review the family’s energy use. With a little awareness, most people can trim their electricity use up to 70 percent, he said. Tripp has been a solar proponent and worker for more than a decade, practicing what he preaches and using what he sells. In remote Polk County, on Big Frog Mountain, the 40-year-old entrepreneur uses the sun to generate his own electricity to power his home. And in his office at the business incubator in North Chattanooga where he markets his designs around the globe, he is installing window canopies that double as a solar energy collectors to power his business needs.