Hybrid trucks are already in commercial production, and with Peugeot’s pending launch of the world’s first diesel-electric hybrid passenger car, the industry is poised for considerable growth. Although the U.S. lags behind Europe in terms of favoring light-duty diesel applications, interest may soon grow as the European market takes off.

The environmental benefits of diesel hybrid technologies are impressive, allowing for an average fuel consumption saving of 20 to 35 percent. When biodiesel is added to the fuel mix, the environmental benefits are even more pronounced, especially when it comes to carbon dioxide emissions.

In mid-2011, Peugeot will launch the world’s first production-scale diesel-electric hybrid passenger car. The 3008 HYbrid4 features an average fuel consumption savings of 35 percent. A traditional two-liter, 163-horsepower diesel engine mounted in the front of the vehicle, and a 37-horsepower electric engine mounted in the rear, provide the car with a maximum power output of 200 horsepower, says Peugeot spokesman Martin Alloiteau. The electric motor can be used as the primary power source during city driving, adds Peugeot spokesman Laurent Debure, but can also be used to boost performance during highway driving.

The 3008 HYbrid4 can be driven in three different modes. The ZEV—or Zero Emissions Vehicle—mode allows the driver to run the vehicle in an all-electric mode when in the city. When placed in auto mode, the electronic components of the car automatically control the entire system, including transitions between the diesel engine and electric motor. Finally, four-wheel drive mode allows both powertrains to work together, with the rear wheels driven by the electric motor and the front wheels powered by the diesel engine.

Although the Peugeot’s 3008 HYbrid4 is particularly notable for its hybrid technology, Debure adds that great care has been taken to ensure the car meets Peugeot’s high-performance standards as well. “We’ve maintained the driving pleasure of the car, which is very important for our brand,” he says. “We don’t only talk about the low fuel consumption of the vehicle, but also try to focus on its performance and drivability. It is a clever wedding between the diesel and electric engines, and we are using the most efficient technologies for this hybrid solution. That’s why we think our world premier will be a success. It’s not a boring car, and it has been designed to be a pleasure to drive.”

While production-scale diesel-electric hybrid passenger cars are a new development for the industry, diesel hybrid technology has been commercially available in heavy-duty trucks for several years. In fact, Eaton Vehicle Group has been working to develop electric hybrid systems for two decades and has been producing them commercially since 2007. The company also began offering a hydraulic hybrid system in 2010.

Eaton provides its technology to major truck and bus manufacturers around the world. The company offers several hybrid technologies, all of which are fuel neutral and can be added to diesel powertrains, says James Parks, Eaton’s manager of global communications-hybrid. Eaton’s hybrid electric technology maintains the conventional drivetrain architecture and is designed to recover power typically lost during braking, and stores it in batteries. The company also offers two hybrid hydraulic systems: one that offers regeneration and launch assist, and another that completely replaces the conventional drivetrain.

Volvo Bus Corp. also has several different hybrid technologies in production today, including those designed for the European and North American markets. The company has been working to develop its diesel hybrid technology since 2002 and began vehicle production in 2006. “We started the industrial-scale production in May 2010,” says Edward Jobson, Volvo Bus environmental director, noting that before reaching industrial production, his company did on-demand building.

Volvo’s diesel hybrid buses are able to achieve a 30 to 35 percent reduction in fuel consumption in the city, and a 20 to 30 percent reduction when highway driving. The Volvo 7700 Hybrid model is what’s known as a parallel hybrid. This means that the diesel engine and electric motor can work either independently or in unison to power the bus. The electric motor is used to start the vehicle and can power acceleration up to approximately 20 kilometers per hour (12.5 mph). When traveling at higher speeds, the diesel engine takes over, supplying the power. Batteries used to power the electric engine are charged by both the brakes and the diesel engine.

Markets, Demand, Cost

Peugeot’s 3008 HYbrid4 vehicle has been designed specifically for the European market. The car will initially be available only in Eastern and Western Europe. Diesel passenger cars in the U.S. don’t have a very good image, which is why hybrid diesel cars—at least in the beginning—will be designed for the European marketplace, says Alloiteau. That doesn’t mean the vehicle won’t be introduced into other markets in the future, but in the beginning it really makes sense to focus on Europe, he says.

“The European market is very keen on diesel engines,” says Debure. In fact, Alloiteau notes that at least half of the passenger cars on European roads are equipped with diesel engines. According to Debure, diesel hybrids are also significantly more efficient and less expensive than their gas-electric hybrid counterparts. “We have chosen to do the diesel because our diesel engine has very good fuel consumption performance, so it was a good base to make a hybrid,” Debure says. “If we had chosen a gas engine with higher fuel consumption, it would be difficult for us to reach our objectives in terms of reducing consumption.”

“In Europe, we are facing very demanding norms in terms of reductions of emissions,” Alloiteau says, noting that the carbon dioxide reduction goals are particularly demanding. Our brand is a leader in the field, and we want to maintain our position, he says. In fact, the 3008 HYbrid4 is just the beginning. Since the HYbrid4 technology is built into the rear suspension of the vehicle, it’s very adaptive to similar platforms and will be added to more Peugeot and Citroën vehicle models in the future.
“The technology will expand to other cars—not small cars and very compact cars in the beginning, but more on the medium and medium-high segment of cars,” Alloiteau says. “In 2015, we think for Peugeot and Citroën the sales on the open market could be approximately 100,000 cars equipped with hybrid diesel technology.”

While the price of the 3008 HYbrid4 has not yet been released, it’s clear there will be a price premium when compared to traditional diesel passenger vehicles. However, a significant portion of the additional cost can be recouped through fuel savings. The price premium for diesel hybrid technology is also expected to reduce as the technology is transferred to additional models and economies of scale improve.

Increased future demand for diesel hybrid technology is not exclusive to passenger cars. Volvo also supplies gas-powered buses to the market. Since the May 2010 launch of its 7700 Hybrid diesel model, Jobson notes that his company has sold more hybrid diesel buses than gas buses. In fact, Volvo has received orders for nearly 200 hybrid buses in its first six months of production. In mid-December, the company secured its largest single order to date when bus operator Arriva ordered 27 Volvo 7700 Hybrid buses, which will be used in Dordrecht, Netherlands.

“Customers are very happy with the hybrid, with the performance, the reliability and the fuel consumption, of course,” Jobson says. “Also—dare I say—the pricing.” Even though hybrid technology does add cost to the vehicle, Jobson says that most customers understand that they can save money over the lifetime of the vehicle. Many also see it as a sort of insurance to protect them from rising oil prices, he continues. Strong demand also means that Volvo will be offering more hybrid options to its customers in the future.

While Peugeot and Volvo are most active in the European marketplace, Eaton has been more active in North American markets. “The majority of our sales are in North America; with China, city bus sales growing quickly,” Parks says. “We’re working hard to grow in Europe, but a lot of the manufacturers there are vertically integrated and, when it comes to hybridization, they’re trying it themselves.” Even with obstacles in the European marketplace, Parks says interest in Eaton’s products has been growing quickly. “Sales have increased steadily since production began in 2007, and we absolutely expect that to continue,” he says.

Like Volvo, Eaton has received extremely positive feedback from its customers, many of whom are placing additional orders. “Some of our earliest customers, who [bought] one or two trucks, are now returning and placing orders for 10 or more hybrids at a time,” Parks says. Eaton is also working to expand its offering. “We’re definitely working to improve the systems and offer our customers more combinations that better fit the needs of their customers,” he says.

Considering Biodiesel

Eaton’s hybrid systems are all designed to be fuel-neutral, and are compatible with biodiesel. “It really doesn’t matter what fuel runs through the truck with our system,” Parks says. “We really don’t touch the fuel.” Rather, each manufacturer employing Eaton’s hybrid technologies likely has its own unique thresholds and guidelines for biodiesel use in its vehicles.

According to Debure, Peugeot’s 3008 HYbrid4 is compatible with fuel containing up to 30 percent biodiesel. “All of our diesel engines are compatible with B30,” he says. Customers who chose to fuel their vehicles with biodiesel-blended fuel will compound fossil-fuel reduction benefits that the hybrid can achieve on its own. This is because the hybrid technology alone can reduce fossil fuel usage by approximately 35 percent. A diesel hybrid fueled by B30 will further reduce consumption of fossil fuels by nearly one-third.

Volvo’s actions in regard to biofuel are particularly notable. The company is currently field testing its hybrid buses with B100. “The evaluation is not finished yet, but the expectation is that we will find that B100 is okay from a technical standpoint, but that you will need to take some service measures,” Jobson says.

When it comes to biodiesel, Volvo is only testing B100 in its diesel hybrid bus systems, no blends. “Either you have it or you don’t,” Jobson says. “If you allow biodiesel, you should be able to run them on up to 100 percent.”

Volvo’s field tests are expected to conclude in 2011. “We don’t know exactly when they will be finished, but we know that it will be finished [this] year,” Jobson says. Some of the anticipated service measures that are expected to be required for biodiesel use include increased intervals for oil and fuel filter changes. “You will also have to change—before you start with the B100—some seals and the fuel lines,” he continues. Specifically, fuel lines made of an alloy that contains copper must be replaced with stainless steel.

Although it is likely Volvo will approve the use of B100 in its hybrid buses, only time will tell if customers will be interested in taking the steps needed to implement the fuel. The use of biodiesel is largely politically driven at the moment, Jobson says, noting that interest in biodiesel tends to rise and fall with political sentiment. “I think there will be some local requests, but it’s very early to guess what the demand will be on the market.”

Author: Erin Voegele
Associate Editor, Biodiesel Magazine
(701) 850-2551
evoegele@bbiinternational.com