Creating a Climate for Change

Renewable Energy on the Road

Inside this Article

The NOLS bus powered by waste vegetable oil
The NOLS bus powered by waste vegetable oil
NOLS marketing rep Nora Kratz
NOLS marketing rep Nora Kratz explains the inner workings of the bus’s waste vegetable oil fuel system.
Installation solar-electric modules on the roof of the bus.
Two members of Creative Energies, a Wyoming-based renewable energy company, install solar-electric modules on the roof of the bus.
PV array on the roof collects solar energy to power electronics on the bus
While students practice their climbing skills, the photovoltaic (PV) array on the roof collects solar energy to power electronics and appliances on the bus.
A toggle switch allows the driver to choose between tanks
A toggle switch on the dashboard allows the driver to choose between tanks of petrodiesel or veggie oil.
The grease-gathering payoff is free fuel
The grease-gathering payoff is free fuel—used fryer oil from a restaurant’s grease barrel—for the bus.
Visitors learn more about NOLS wilderness adventures on the PV-powered TV
Visitors learn more about NOLS wilderness adventures on the PV-powered flat-screen TV.
Some of the PV system’s components are housed in the bus’s storage compartments
Some of the PV system’s components, such as the charge controller and battery bank, are housed in one of the bus’s storage compartments.
The NOLS bus powered by waste vegetable oil
NOLS marketing rep Nora Kratz
Installation solar-electric modules on the roof of the bus.
PV array on the roof collects solar energy to power electronics on the bus
A toggle switch allows the driver to choose between tanks
The grease-gathering payoff is free fuel
Visitors learn more about NOLS wilderness adventures on the PV-powered TV
Some of the PV system’s components are housed in the bus’s storage compartments

There’s nothing like a colorful 36-foot-long bus to turn heads. Especially if it has a climbing wall bolted to one side, solar-electric modules on the roof, and a tailpipe that burps out the unmistakable odor of french fries.

The bus, owned by the nonprofit National Outdoor Leadership School (NOLS) and funded through a partnership with Stonyfield Farm (maker of organic dairy products), is powered by a diesel engine with a modified fuel system designed to run on waste vegetable oil (WVO)—a renewable alternative to petroleum diesel. Eight solar-electric (photovoltaic; PV) modules on the roof produce electricity for the bus’s outdoor theater, audio equipment, lights, computers, and refrigeration units.

With 50,000 miles and 820 days on the road under its belt, the NOLS bus and its crew are crisscrossing the country to promote the school’s mission—to be the leading source and teacher of wilderness skills and leadership that serves people and the environment.

Environmental Consciousness

In its 40-year history, NOLS has been a pioneer in the field of wilderness and leadership education all over the world. In 2004, when the school was searching for an innovative way to spread its educational message, a veggie-powered bus seemed like a natural fit. As the demand for petroleum rises, the remote, wild places that serve as NOLS’ wilderness classrooms are increasingly threatened by petroleum and natural gas development—areas like Wyoming’s Red Desert, the Arctic National Wildlife Refuge in Alaska, and Utah’s Green River corridor.

NOLS estimates that their WVO approach has saved 5,000 gallons of petrodiesel so far, neutralizing associated carbon dioxide emissions, eliminating sulfur dioxide emissions, and significantly reducing the release of other harmful pollutants. Meanwhile, the PV array on the roof produces clean electricity from sunshine—eliminating the pollution associated with fossil-fuel-based electricity production.

With a new bus tour for 2007, “Creating a Climate for Change,” the use of renewable energy sources like WVO and solar electricity is both timely and influential. The campaign will combine renewable energy education with NOLS’ leadership values, along with information on Stonyfield Farm’s sustainable, organic farming practices.

As the bus travels along, stopping at schools, outdoor stores, concerts, and “green” events, the crew hosts fly fishing and wilderness medicine clinics, shows outdoor films on their PV-powered theater system, and spots climbers on their portable bouldering wall. Inside, pictures of graduates from NOLS courses around the world cover the walls, and visitors can learn more about NOLS and sample Stonyfield Farm yogurt while the crew explains the workings of the WVO system and the benefits of using renewable fuel sources.

Veggie Conversion

After the idea was sparked, NOLS implemented the bus’s WVO conversion with the help of California-based Veg Powered Systems. A diesel mechanic for more than 20 years and the company’s owner, Joel Woolf worked for a week with NOLS employees Jared Scott and Matt Armstrong to install the special fuel system.

The stock diesel fuel system—complete with 100-gallon tank, lines, pumps, and filters—was left intact and functional. Woolf and the NOLS team simply installed a second, distinct, parallel fuel system. The veggie oil fuel system is almost identical to the stock diesel fuel system with one notable extra—it’s heated. Copper tubing, coursing with hot engine coolant, is coiled around the WVO fuel line and inside the 90-gallon WVO tank.

A toggle switch in the driver’s cab controls which fuel system is being used, but the bus is always started and shut down using the conventional or “dino diesel” system. As the Caterpillar 3116 diesel engine heats up, it transfers that heat to the coolant, which in turn transfers it to the veggie oil fuel lines and tank. In approximately five minutes, the WVO is warmed and thinned enough to run through the fuel line, pumps, and a diesel fuel filter, and into the fuel injectors.

Aside from the heat needed to reduce the WVO’s viscosity, the only other requirement for running veggie oil fuel in a diesel engine is thorough filtration. To ward off the inevitable chunks of tortilla chips and wontons, Armstrong designed, built, and installed an in-line prefilter system. When compared to the low-tech solution of nylon sock filters favored by many WVO users, Armstrong Technologies’ 30-gallon filtering unit seems like a sci-fi collaboration between NASA and Rube Goldberg.

For the bus’s high fuel demands and crew’s tight time constraints though, it’s just the thing. Veggie oil can be scooped, poured, or pumped straight from a waste receptacle into the filter system, where it is heated by PV-powered water heating elements and pumped through progressively finer wire-mesh filters en route to the WVO fuel tank. And the icing on the fossil-fuel-free cake? The entire process is powered with electricity from the solar-electric array.

Free Fill-Ups

When it comes time to fill up at the pump, the savings of using WVO really add up. The bus gets roughly the same mileage running on WVO as it does with petroleum diesel—between 5 and 12 mpg depending on road conditions and oil quality—but the waste veggie oil is free. Many restaurants and dining halls are happy to get rid of their unwanted, leftover oil. After being used to make french fries, chicken nuggets, egg rolls, or tempura, the oil gets filtered into the bus’s WVO fuel tank. The bus crew frequents higher-quality Chinese and Mexican restaurants for the best oil. Fast food chains, they say, use hydrogenated oil, which can clog the fuel injectors.

The fuel-finding expeditions go something like this: Slink down alleys looking in grease disposal barrels, knock on back doors, and be prepared to answer a lot of questions. “Some restaurants think it’s a prank,” says Matt Copeland, NOLS marketing manager and former bus marketing rep. “They’ve  been throwing the oil away or paying to have it removed for years, and now someone wants it.” The owner of a Chinese restaurant in Laramie, Wyoming, tried to talk the bus crew out of taking his used veggie oil. “He said to us, ‘Are you sure you want to do this? You’ll ruin a perfectly good bus!’” recalls Copeland. Besides free fuel, an added bonus is that grease-finding efforts are another opportunity to educate people about the benefits of veggie oil fuel.

PV Power

Creative Energies, a renewable energy company in Lander, Wyoming, installed the solar-electric system on the bus. Led by former NOLS instructors, their crew initially installed six BP125 125-watt PV modules, and recently added two Evergreen 120-watt modules, on the bus’s roof. The array produces DC electricity that’s stored in six Trojan L16 batteries inside one of the bus’s storage compartments. An OutBack MX60 charge controller manages and optimizes the battery charging from the solar-electric array.

Fans and interior lights are run at 12 volts DC, while everything else runs on 120 volts AC provided by a pair of OutBack FX2012, 2,000-watt inverters. The system, of course, depends on the sun, but can collect some solar energy even on cloudy days. The system is monitored with both an OutBack Mate and a TriMetric 2020 amp-hour meter, mounted in the cab of the bus. The batteries can be charged from the solar-electric array, an onboard Honda generator, or by plugging into the grid if it’s available. The system does not currently use the alternator of the bus for system battery charging.

The system generates and stores enough electricity for the bus’s educational and operational needs. The sun can hide for a few days without forcing electricity rationing for the two 12-cubic-foot Crosley high-efficiency chest refrigerators, 36-inch flat-screen television, public address system, stereo, dome lights, or outdoor theater. In fact, the only significant challenge to NOLS’ solar-electric system is powering the WVO filtering system.

But even that daunting task is managed quite nicely by Creative Energies’ design. According to Copeland, “Phil, Toby, and the rest of the Creative Energies team performed a thorough needs and use analysis. Recognizing the need to balance desired capabilities with the budget constraints of a nonprofit and the space constraints of a bus’s roof, they were able to design and implement a system that has performed beautifully. Nine times out of ten, we’re able to meet our grease-filtering needs with the solar reserves, but it’s nice to know that we have the ability to plug in or run the generator if need be.”

Promoting Change

“When we first went on tour in 2004, we were met with confusion,” admits Copeland. “But, with time and more public awareness of renewable energy, the concepts have become more accepted, and people walk away excited.”

Some seek out the bus to swap stories and tips, or to show off their own veggie-powered vehicles. “When we’re on the road, every grease car in town comes by,” Copeland says. “They’re always very helpful and willing to exchange information.” Some of them even come bearing gifts of WVO. One couple in Santa Fe, New Mexico, stopped by a bus event with leftover oil from frying their Thanksgiving turkey.

Whatever types of interactions the big bus sparks, one thing’s for sure—it’s getting people thinking about change. “Driving a veggie-powered vehicle and becoming electricity independent may not be feasible for all of us,” says Copeland, “but the power of the bus is that it gets people to take a good hard look at the status quo and consider creating change.” Meanwhile, the NOLS crew has grown used to the stares, waves, and beeping horns that follow wherever the bus goes.


Joanne Kuntz, National Outdoor Leadership School, 284 Lincoln St., Lander, WY 82520 • 800-710-6657 or 307-332-5300 • Fax: 307-332-1220 •

Creative Energies • 866-332-3410 • • PV system installer

Veg Powered Systems • 805-525-4515 • • Vegetable oil fuel system conversion

PV System Components:

Bogart Engineering • 831-338-0616 • • TriMetric battery monitor

BP Solar • 800-521-7652 • • PV modules

Evergreen Solar Inc. • 508-357-2221 • • PV modules

OutBack Power Systems • 360-435-6030 • • Inverter, charge controller, monitor

Trojan Battery Co. • 800-423-6569 • • Batteries

Xantrex Technology Inc. • 800-670-0707 or 604-422-8595 •

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