Solar isn’t anywhere near the boiling point yet. But if you want to save on diesel while you keep your truck battery charged and run basic power tools and laptop computers, it’s becoming an option.
Solar panels are a common sight in farmers’ fields and atop barns and houses. Small solar systems power parking meters and illuminated road signs. And if you look carefully enough you can sometimes spot panels on trucks.
Minnesota-based Thermo King, a division of Ingersoll Rand, manufactures truck-mounted solar systems designed to help food transport vehicles meet refrigeration needs.
Aftermarket product manager Paul Kroes says his company responded initially to growing demand to support truck batteries, and he’s now finding demand broadening beyond that.
“At the various trade shows we’ve been at, everyone’s coming out of the woodwork saying they have a particular application and asking what solar can do to support it,” Kroes says. “We’re quickly getting to the point where we will have a solution for everybody and everything.”
While heavy load demands aren’t currently feasible with solar, Kroes thinks it’s just a matter of time, economics, and technological development.
Subhed: Still years away from competing with diesel
“Given the cost of solar, a diesel generator is much more cost-efficient,” Kroes says. “But I believe in the next five to 10 years we’ll be at the point where solar could be an even more cost-effective solution than a generator. We’re just not there yet.”
Given that trucks have limited surface space, the answer will likely lie in increased power storage, he says.
For now, Thermo King concentrates on what solar can currently tackle. The company does its own end design but sources solar equipment from an outside supplier.
Thermo King dealers can install systems, and some customers do it themselves, Kroes says.
“There’s not a lot required to it,” he explains. “The panels have an adhesive backing, so you don’t have to worry about drilling holes into the tops of cabs.”
Kroes described the adhesive as very aggressive, able to withstand rough weather, but removable with special solvents. Still, he adds, metal fasteners are available.
Thermo King’s biggest seller so far is its 26-watt system, with a panel measuring one by two feet. Some customers have enough room for two or three of them.
Food industry delivery vehicles use them to boost refrigeration, utilities use them to run basic office equipment, and slowly but surely they’re moving into the service truck market.
Subhed: Solar useful for low-draw equipment
Like any new technology, it’s early days. SpaceKap, a Quebec manufacturer of fiberglass pickup truck caps and slip-in transferable service bodies, is testing solar systems and has even provided quotes to a few prospective customers, according to account manager Sean Brideau.
SpaceKap users include utilities, telecommunications companies and other fleet owners across North America. Brideau says his company acquires panels and other components from Carmanah Technologies Corp. through the British Columbia company’s Go Power! product line, and outfits service bodies so solar capability is self-contained, without messy external or extraneous wiring.
Brideau is gung-ho about new mobile uses for solar panels. But he’s equally clear that benefits are currently limited to keeping truck batteries charged and operating basic power tools, interior lights and other low-draw equipment without idling or using a generator.
“We’ve done testing so far with three 40-inch LED light bars in our SpaceKap, and the 100-watt solar panel from Go Power! provides more power than those lights draw,” Brideau says. “While the lights are running the solar panel is still keeping the battery fully topped-up so you’re not losing any power at all.”
Of course, serious service trucks employ an array of higher-draw machines that mechanics use in challenging venues such as construction sites, mines, and the oilpatch. For now, though, fiber-optics maintenance crews and others with light-duty needs are most likely to benefit, Brideau says.
“For compressors you would need extra batteries inside, and we haven’t got to the point of testing that,” Brideau says. “We’re mostly dealing with mobile office units which have a 2,000-watt inverter, a smart battery charger, transfer switch — stuff like that.”
Carmanah Technologies is a dominant player in mobile solar technology in North America. Sean O’Connor, sales channel manager for its Go Power! product line, agrees solar isn’t yet ready for larger service trucks. Compressors and small truck-mounted cranes draw immense loads and there simply isn’t enough surface room on a service truck for many panels, he explains.
“Unless they had a trailer of batteries and solar behind it, we couldn’t ever offset the whole thing.”
For now, Carmanah customizes systems for users wanting to prevent batteries from slowly discharging over time and who want to run a few basic AC devices.
These systems can deal with routine low-scale parasitic power demands from small, flashing LED indicators or other extras commonly found in trucks. “Every time it’s light out, it makes sure the battery’s topped up,” O’Connor says.
“Some trucks might sit for a length of time, say over a long weekend, and the mechanic returns to the truck and it won’t start. That costs them money, because they’re not doing the work they’re supposed to be doing, and they have to pay for a jump start or for new batteries.”
Industry still in its infancy
Carmanah isn’t the only manufacturer. Rhode Island-based eNow Energy Solutions also supplies solar auxiliary power systems for the transportation industry.
Sales manager John Switzer says customers use his company’s systems to power lighting, lift gates, HVAC, and other equipment in tractor-trailers and a range of smaller trucks used by utilities and municipalities.
“We work with our customers to understand what the electrical load is on their vehicle,” Switzer says. “We figure out how much energy they’re drawing off the battery and then we design a solar system able to offset that load.”
While eNow does its own design and manufacturing, there aren’t too many companies producing flexible solar technology for vehicles.
“It takes a lot of different design and engineering work in order to get a viable solution to be able to withstand the environment that you see on the top of a vehicle,” Switzer says, referring to factors such as wind, weather and road salt.
Although eNow has made little for the service truck market, it did produce a 5,000-watt system that went on top of a trailer as part of the U.S. Department of Energy’s SuperTruck program.
“We were told to install as much solar as we could,” Switzer says, adding that program administrators were looking to improve fuel economy.
A system that high-end will likely cost more than the industry average. Talk to each manufacturer or vendor, and prices vary depending on wattage and accessories. Panels alone can run upwards of $500, and entire systems can exceed $2,500.
Of course, prices are always subject to change in a field that is clearly in its infancy. Time will tell where solar technology goes and whether efficiencies can be found that will give it more shine in the service truck market.
Switzer expresses optimism: “As we see solar technology gaining momentum and acceptance in the market, you’re going to see increases in panel efficiency and power density.”
Saul Chernos
Service Truck Magazine