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Greener Fleets

Posted by Jessica Porter

Jul 18, 2016 2:09:18 PM

Electric and biodiesel offer contractors renewable alternatives to fossil-fuel powered vehicles. Here’s where they stand.

THOUGH DIESEL VEHICLES remain the workhorses of many industries, owners of diesel vehicles are beginning to look to alternative fuels that lessen the environmental impact, reduce dependence on foreign oil and save some money at the pump. The two most realistic alternatives (for now) are electric and biodiesel.


City buses, delivery trucks and sanitation vehicles are good fits for electric motors because they make frequent stops.

Natural gas-powered vehicles, adopted by many municipalities, are, in our view, a non-starter. They reduce air pollution at the point of use, but the hidden costs of fracking and other extraction methods make gas a very dirty fuel. Fuel cells are promising, but so far no one can make the numbers work for small-scale commercial use. So we’re left with the big two. Let’s start with electric.

Electrics: The Battery Conundrum

Electric vehicles are taking the automotive industry by storm, due to their proven impact on reduced emissions and fuel consumption. However, manufacturers have had trouble designing an electric drive capable of enough range using current battery technology. But the sweet spot may just lie in fleet vehicles that make frequent stops, such as delivery trucks, city buses and sanitation. Some companies that fit this niche, including FedEx and Frito-Lay, are moving into the electric vehicle market.


In 2014, FedEx ordered two medium-duty powertrains from Wrightspeed, which specializes in creating range-extended electric vehicle powertrains for fleet vehicles. Soon after, FedEx ordered 25 more. The Wrightspeed Route is a “repower” powertrain kit engineered for the delivery and service fleet markets. The Route replaces a truck’s diesel engine, transmission and differential.

Magnesium Batteries. A New Hope?

Toyota Research Institute of North America has been tweaking a new battery technology it says could address the biggest issue facing heavy electric vehicles: battery storage. This technology could result in rechargeable magnesium batteries to replace lithium batteries. Magnesium metal is a safer alternative to lithium metal, which is unstable and can ignite when exposed to air in its natural state. When used in a battery, ions are taken from lithium metal and put into graphic rods—a process that results in less actual metal and makes the battery able to hold less power.

Until recently, researchers have not been able to determine ways to use magnesium in a battery, even though it’s more stable. But Toyota researchers found a way to use a hydrogen storage material that may lead to the creation of longer-lasting magnesium batteries.

The Route needs to be plugged in overnight and gets 20 to 25 miles of range on a full charge. However, every time it stops, the battery charges. During the drive, the diesel-powered turbine generator kicks on to provide extra range.

“Because the range extender is on there, you can get roughly three charges from full tank, which will get a FedEx driver through his route,” says Wrightspeed Product Manager Arlan Purdy.

This technology can save fleet vehicles that stop frequently up to 60 percent on fuel. “When you’re paying for an EV, it’s always in saved fuel,” Purdy says. “A lot of fuel is wasted in these frequent stop applications.”

These vehicles use a diesel-powered turbine generator, which is the same style of technology used in grid generators and the same combustion used on aircraft engines. “Turbines run at a very high speed” Purdy says. “By using a turbine specifically, you get best out of combustion and electric technology.” Turbines also burn cleanly and produce cleaner emissions.

Another key component to Wrightspeed’s vehicles is using a 39-kilowatt-hour lithium-ion battery pack. “We’re using one of the more expensive batteries. But that’s due to insight our founder had to package it all together using higher power batteries and motors—and then backing them up with a turbine generator,” Purdy says. “A lot of people go with a piston engine, which is less efficient.”

FedEx also is able to save significantly on maintenance with Route vehicles. “Aircrafts use turbine engines because there are fewer moving parts, making them easier to maintain,” Purdy says. “You also eliminate all common maintenance issues, such as replacing pistons and doing oil changes. Owners also are probably not doing brake jobs during life of the vehicle.”


FedEx isn’t the only company adding electric vehicles to its fleet. Frito-Lay uses more than 250 Smith Newton electric delivery vehicles, according to a National Renewable Energy Laboratory (NREL) report. NREL states the vehicles are powered by two lithium-ion batteries that provide about 350 VDC and 80 or 120 kWh of energy storage, depending on the configuration. The batteries charge overnight and provide between 50 and 150 miles of range, according to Frito-Lay. The vehicles can reach a top speed of 55 mpg.

According to NREL, the vehicles include a brushless, permanent magnet motor with 134-kW peak power. Regenerative braking charges the batteries when the operator brakes, giving the vehicles that range needed in traffic and when stopping frequently.

World's Largest Dump Truck is electric

An electric motor powers the world’s largest dump truck, the BELAZ-75710.

World’s Biggest Dump Truck Is Electric Powered

In case you were wondering if electric motors could handle heavy lifting, the world’s largest dump truck—the all-electric BELAZ-75710—can haul 500 metric tons of materials. According to Siemens, that’s equivalent to seven fully fueled and loaded Airbus A320-200 planes and beat the previous record by 25 percent.

The final product includes four Siemen’s 1,200-kW electric motors to haul the heavy loads and the truck’s 360-ton unloaded weight. The dump truck is all-wheel drive and includes four-wheel hydraulic steering. Unloaded, it can reach up to 64 kilometers per hour. The truck is 20 meters long, 10 meters wide and has a height of 8 meters, according to Siemens.


Biodiesel is manufactured by transesterification, a chemical process during which glycerin is separated from fat or oil. This process results in the production of biodiesel and glycerin, which is used in soap and many other products, according to biodiesel.org.

Biodiesel. Transitional Fix

Biodiesel is one solution that could transition the truck industry to a clean-air future. But the fuel isn’t perfect, and has its detractors. Critics note that growing corn for biofuels instead of food robs Peter to fuel Paul, for example. But the new sources of biofuel may address some of these concerns

“Historically, about half of all U.S. biodiesel is made from soybean oil, while the other half comes from all other feedstock sources,” says Kaleb Little, senior communications manager of the National Biodiesel Board. “As industry volumes grow, we see the sources biodiesel is made from grow, too—including more unconventional fats and oils with things like brown grease from municipal waste water treatment facilities.”

The biodiesel industry has grown from 250 million gallons to more than 2 billion gallons during the last 10 years, according to Little. Part of that growth is due to the construction industry. In the past few decades, emphasis on more sustainable building has increased dramatically, evident through programs such as LEED.

Now, these programs are mainstream—resulting in clients and owners demanding efficient buildings and construction processes. That effect is trickling down the industry, and contractors are looking at ways to increase the efficiency of their vehicles.

“Biodiesel can be a huge part of greening efforts in the construction industry,” Little says. “It’s an industry that relies heavily on diesel equipment and can make an immediate impact on air quality and reduce emissions by simply switching to a cleaner-burning fuel like biodiesel.”

Biodiesel burns much cleaner than petroleum diesel, reducing particulate matter, carbon monoxide, unburned hydrocarbons and other smog- causing particles, according to Little. It also significantly reduces lifecycle emissions and has the highest energy balance of any liquid fuel.
“For every one unit of energy it takes to make biodiesel, more than 5.5 units of energy are returned,” Little says. Biodiesel is less toxic than table salt, making it safer to store, handle and use, and it biodegrades faster than sugar.

When used as a pure fuel (not an additive), it results in 48 percent lower direct source CO2 emissions and 12 percent lower direct source emissions than petroleum diesel, according to the Environmental Protection Agency (EPA).

Currently, biofuel is the only alternative fuel designated by the EPA for commercial-scale production. In 2015, the United States consumed 2.1 billion gallons of biodiesel, which reduced carbon emissions by 18.2 million metric tons—more than the emissions from all the cars in Colorado and Connecticut combined, according to Little.

Biodiesel is the most commonly used alternative fuel option on the market today, with 18 percent of fleets in North America using it, according to The Association for the Work Truck Industry’s (NTEA) 2016 Fleet Purchasing Outlook study.

Biofuel Compatibility with Diesel Vehicles

“Biodiesel blends of 20 percent and below will work in any diesel engine without the need for modifications. These blends will operate in diesel engines just like petroleum diesel,” Little says. While a blend of 20 percent biodiesel to 80 percent petroleum diesel is not great, it’s a start. This blend also will result in similar horsepower, torque and mileage as diesel.  

Using a blend, it’s a viable option for many different industries to use in heavy machinery such as bulldozers and excavators, pickup trucks, semi-trucks, school buses, snow plows, smaller sedans, and even home heating systems and boats.

In fact, respondents to the NTEA’s study represented a wide range of fleet sizes, vehicle weight classes and truck applications in the government, municipal, construction, delivery, utility and agricultural industries. “Biodiesel has widespread support across all diesel applications because it is easy to use with existing infrastructure,” Little says. “The use of biodiesel is as diverse as the diesel engine itself.”
Today, most major engine manufacturers support using biodiesel, including Ford, General Motors and Fiat Chrysler. “More than 78 percent of all diesel vehicles coming off production lines today cite biodiesel use in their owner’s manuals,” Little says.

Biodiesel and Heavy Equipment

Catepillar 336E H Hybrid

Cat’s 336E H Hybrid is a hydraulic hybrid excavator that reduces fuel consumption by 25 percent.

Contractors that regularly use heavy equipment are reaping the benefits of biodiesel in their machines as well, due to higher fuel savings and lower impacts on the environment. Biodiesel works with most diesel engines, but only as a blend.

For example, John Deere engines can handle biodiesel blends of B5 to B20, which means 5 percent to 20 percent biodiesel mixed with 80 percent to 95 percent petroleum diesel. Without an exhaust filter, up to B100 (100 percent biodiesel) can be used, if permitted by law and certain specifications are met, according to John Deere’s website.

However, because biodiesel is considered an ultra-low sulfur diesel fuel, it increases lubricity and can cause users to need to replace filters more frequently. In addition, many contractors switch to a lower blend, such as B5, in cold weather months due to the fuels increased lubricity.

However, biofuel is a controversial topic among rental companies. For some, the reduction in harm to the environment and client demand for cleaner fuel make the switch to biodiesel easy. But others are less willing to make the jump, as they are nervous about the fuel’s potential impact on equipment’s engines.  

Currently, most manufacturers recommend a maximum of B5, meaning 5 percent biodiesel mixed with 95 percent petroleum diesel. Some contractors are fueling with significantly higher blends without experiencing negative consequences, but others are hesitant to not follow manufacturer recommendations.

Hybrids: Meeting in the Middle

Hybrids use a combination of fuel and alternative power, which typically is electric. While truck manufacturers are producing electric hybrid pickups (see Part 1), equipment manufacturers are working on other forms of hybrid power. Hydraulic hybrids can be more efficient options for heavy equipment because they don’t need the same cooling controls as electric motors.

Cat’s 336E H Hybrid, its newly released hydraulic hybrid excavator, uses the company’s already established and standard hydraulic components to reduce fuel consumption and decrease cooling demands. And just because it’s a hybrid doesn’t mean users will sacrifice performance—it provides the same power as the standard machine.

The machine reduces fuel consumption by 25 percent, which is results in 66 fewer tons of CO2 produced than the standard 336E in one year, according to Cat. The fuel reduction is due to lower engine rpm than the standard model compensated by a larger displacement, electronically controlled pump. It’s also due to an auto engine idle shutdown process and auto engine speed control, according to Cat. In addition, the 336E H Hybrid is 98 percent recyclable.

The potential market for more efficient work vehicles is wide open. We expect that opening will be filled with a combination of new fuels, better engineering, and changes in how work is done. 

Fueling with 100 Percent Biodiesel

Though most diesel engine manufacturers don’t recommend using blends higher than B20, some people choose to fuel with B100—100 percent biodiesel. While it may be better for the environment, owners must take a few extra steps when fueling with B100.

B100 is compatible with engines built in the last 20 years with biodiesel-compatible material for hoses, gaskets and other parts, according to the U.S. Department of Energy’s Alternative Fuels Data Center. However, if a vehicle is not equipped with compatible parts, they can be installed by a mechanic.

Straight Vegetable Oil Straight vegetable oil (SVO), another type pf plant-based fuel alternative, can also be used in modified engines. Diesel motors designed for low-emissions or low-sulfur typically are easier to convert to SVO. Because SVO is thicker than diesel, it works best with trucks that have an injection pump. Cars Direct recommends converting Chevrolet Silverado, GMC Sierra and Ford Super Duty trucks.

Kits are available that can make diesel vehicles run on vegetable oil. They typically cost between $1,000 and $2000 depending on the size of the vehicles—and another approximately $1,500 for installation. However, drivers can install the kits themselves with the proper education. To view installation instructions for select vehicles, visit www.goldenfuelsystems.com.

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