As published in Supply Chain Dive
Solar panels on trucks can supplement battery and power lift gates, though the technology today isn't enough to power a truck down the road.
Sustainability has taken a key place in logistics decisions, and also could figure strongly in a fleet manager’s consideration of solar, Maine Pointe's Michael Notarangeli told Supply
Chain Dive. Read on...
Galileo said, "The sun, with all those planets revolving around it and dependent on it, can still ripen a bunch of grapes as if it had nothing else in the universe to do."
So what’s one more task for Ol’ Sol? In addition to ripening those grapes, the sun also can help keep them fresh as they’re transported from farm to market to home. According to a report from the North American Council for Freight Efficiency (NACFE), "interest in solar panels is growing among fleet managers because truck batteries are often no longer able to meet the power needs of today’s trucks due to increased driver comfort demands, idle reduction regulations and increased tracking requirements."
The 3 use cases for solar on trucks
Solar panels for trucks differ from those we’re used to seeing on fixed buildings, which are rigid and thick. Panels for trucks are flexible, thin, lightweight and can be affixed to the curves of a tractor. The NACFE report focuses on the three primary uses of solar on tractors:
- Supplementing the battery power for heat, ventilation and air conditioning (HVAC) systems.
- Hotel loads (televisions, coffee makers and microwaves, for example) in the sleeper area.
- Lift gates.
A number of trends are driving the advancement of solar technology for trucks, including the driver shortage, hours of service regulations, the solar investment tax credit and even the emergence of commercial battery electric vehicles, the report said. "Solar technology is also constantly evolving, and the future might lead to improved technologies, cost reductions, more electrification of trucking loads, and extended trade cycles."
Solar panels can extend the run time of battery HVAC systems, not only to help the HVAC system make it through the night without draining the truck’s batteries, but also to reduce the load on the alternator the next morning, the report said.
Trucks often have to idle while waiting for a dock at the distribution center or while making deliveries. Many municipalities have regulations to prevent idling and Walmart, for one, doesn’t allow idling for trucks that stay overnight.
Idling also can lead to premature aging of the truck engine, Guy Shaffer, chief marketing officer of eNow Energy, a Rhode Island manufacturer solar panels, told Supply Chain Dive.
"Idling puts about 7 miles on an engine for every hour it idles," he said. "Engines have a diesel particulate filter (DPF) and when the truck is idling, the temperature is not as hot as it needs to be to burn off the particulate. It costs $1,500-$2,000 to replace the filter and $1,000 to clean it."
Multiple stops on a delivery route can put extra stress on lift gates, especially when they are handling heavy loads or running a high number of daily cycles. Shaffer noted a food-service company on Long Island that sends about a dozen trucks a day into Manhattan. In addition to the stress on the lift gates, the company amasses numerous traffic tickets for idling while powering the lift.
Generally, the engine’s alternator is too small or doesn’t have enough run time to keep up with battery demand, according to the eNow website. One driver, Shaffer said, told him "I’m going through alternators like candy."
Basically, solar panels replenish batteries to full charge around sunrise and then go into a "trickle" charge to continually charge the batteries during daylight hours. Energy used during the lift gate operation is continuously replaced.
The business case for solar
Solar panels, at least as the technology exists today, don’t produce enough energy to power a truck down the road, pointed out Michael Notarangeli, EVP of logistics at global supply chain consultancy Maine Pointe. They can, however, provide power to systems like lights, air conditioning, lifts and internal auxiliary power.
Adding solar panels also can play a role in easing the driver shortage, Greg Hirsch, senior vice president at Daseke, told Supply Chain Dive via email.
"Solar panel use can extend a truck’s battery life, meaning fewer jump starts or a reduced need for roadside assistance," he said. "Additionally, for day-to-day living and cab comfort, solar panels provide the necessary power to run such cab-based items as small refrigerators, TVs, microwaves and small electronic devices." Drivers also can run their HVAC system throughout the night without draining the truck or idling the tractor, which can be a key benefit toward driver recruitment.
Sustainability has taken a key place in logistics decisions, and also could figure strongly in a fleet manager’s consideration of solar, Notarangeli said via email.
The main incentive for a fleet manager to make the decision to go with solar panels would be to comply or to take a bold, first step as part of a broader, multi-faceted, sustainability program, he said. "Sustainability programs often require a minimum of annual progress reporting, and may be a table stakes issue for the award of new business, so it’s a strategic decision with longer term implications rather than a cost-savings initiative."
In addition, some buyers require their suppliers to report green initiatives, so operators may decide to install solar panels as part of an internal values-driven program. That, Notarangeli noted, would be an investment in the program, and would defray operating costs over time, but also would be a net add in the short run.
Will solar cut fuel costs?
Fuel efficiency is important to the trucking industry for cost and sustainability reasons. After all, the average Class 8 truck (the heaviest at more than 33,000 pounds) gets just 6.4 miles per gallon and travels about 100,000 miles per year, according to trucks.com. The addition of a solar panel system to a trailer may both extend battery life and reduce emergency roadside calls due to dead batteries. If there is a positive return on investment for the addition of a solar panel system, this is where to expect the savings, according to the NACFE report. Fuel savings are generally a very small part of the overall benefit that comes from a solar panel installation.
"Most fleets we talked to implemented solar panels primarily based on an assumption of improving driver retention and thus avoiding hiring and training expenditures," the report said. "We think it is reasonable given the very high cost of hiring and training drivers that a benefit of $100 per truck per year is a valid assumption if solar panels are installed on the vehicle.”
However, the fleet manager still must convince the C-suite, especially the CFO, that solar is worth the investment.
"Logistics managers are all about the bottom line — getting product from point A to point B," Hirsch said. "Therefore, the decision to adopt solar paneling is entirely dependent on efficiency. Ideally, if the sun is high and the weather is good, solar power can cut back on certain kinds of delays, jump starts and idle time, ultimately easing a logistics manager’s job."
Don’t expect to see heavy-duty trucks powered entirely by the sun rumbling down the highways any time soon. There have been some limited tests for lighter vehicles that have been somewhat successful, according to Notarangeli, but not for the hours of service necessary to fuel a solid business case.
"It’s really a physics problem — weight, mass and friction," he said. "The solar panels would not be able to keep up with the consumption of energy required to move the weight of a truck down the road."
As it currently stands, solar isn't able to produce sufficient energy to completely power a truck and replace diesel with electric-powered engines. It is, however, mature enough to play a considerable role in any sustainable freight program and can be used to power adjacent systems such as lights, AC, lifts and internal auxiliary power.
Increasingly, buyers are requiring suppliers to report their green initiatives as part of their overall annual sustainability goals. Also, the operators themselves may decide to install solar panels as part of their own internal program. Operators can make the decision today to incorporate solar as part of a broader compliance initiative.
Trucks versus cars
Solar innovators looking for a good use case for pilot programs will need to compare the practicality and costs involved of solar on truck fleets versus passenger automobiles. The first and most important factor in creating an initiative is to have reasonable expectations from the panels. Solar panels may make more sense on truck fleets because the panels would be on the roof of the trailer, out of sight, and could provide power to auxiliary systems or be used to recharge the main batteries, potentially reducing maintenance and roadside service calls.
Automobiles, however, lack the surface area of trucks and, unlike solar on trucks, the panels on cars would be visible. The smaller surface area, along with the aesthetic factor, would play a major role. Some industrial fleet operators may prefer the visibility of solar panels for public relations reasons, to illustrate their compliance with green goals or to promote their own value-driven programs. For consumer passenger vehicles, the aesthetic factor would have to match buyer expectations.
Factors in the decision to go solar
Pilots of solar-enabled fleets are already in place. While there is not yet enough data to gauge the real impact, we can look forward to meaningful data in the future as large-scale efforts continue. From a cost perspective, installing panels has to be seen as a long-term investment. Operators considering running a pilot need to be fully aware that, while going solar would defray operating costs over time, it would result in a net add in the short run.
Part of the decision on whether or not to deploy a solar-enabled fleet is simply geography. It stands to reason that the best places to begin a pilot would be the areas which get more days of sunshine per year, such as Arizona or Florida; migrating to other areas later on as appropriate. Another factor is the type of fleet; a dry van fleet will be best suited to pilots because of the available real estate on the roof. A further consideration is that installing panels may add height to the vans, something that will have to be factored into the overall design.
Since the monetary benefits are longer-term, the short-term cost of panels and associated equipment, installation and maintenance would need to be budgeted on a go-forward basis, and the program would need to be part of a strategic policy decision by company leadership. The decision to go solar would be incremental to other fleet costs, and therefore must be a new investment.
Sustainability programs become table stakes for new business
Fleet managers may have several powerful incentives to deploy a solar initiative, including compliance with green goals, or taking a bold - and highly visible - first step as part of a multifaceted sustainability program. Generally speaking though, these initiatives rely on a portfolio of initiatives, one of which would include solar but would, by necessity, have to include multiple approaches.
These sustainability programs typically require annual progress reporting and may even be table stakes for gaining new business. As such, fleet operators may see solar initiatives in a positive light, not necessarily as a cost-savings tactic, but as part of a longer-term strategy for growth. Taking a Total Value Optimization (TVO) approach may require an early investment to gain longer-term cost reductions as well as driving growth and attaining new business by attracting buyers seeking strategic partners with formal sustainability programs.
Michael Notarangeli is Executive Vice President Logistics at Maine Pointe, a global supply chain and operations consultancy.